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Clinical Anatomyfor Your Pocket

Douglas J. Gould, Ph.D.Associate Professor, Division of Anatomy

The Ohio State University College of Medicine

Columbus, Ohio

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Library of Congress Cataloging-in-Publication Data

Gould, Douglas J.

Clinical anatomy for your pocket / Douglas J. Gould.

p. ; cm.

Includes index.

ISBN-13: 978-0-7817-9193-9 (pbk. : alk. paper)

ISBN-10: 0-7817-9193-6 (pbk. : alk. paper) 1. Human anatomy—

Outlines, syllabi, etc. I. Title.

[DNLM: 1. Anatomy. QS 4 G696c 2009]

QM31.G68 2009

611—dc22

2008024080

DISCLAIMER

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Health professions’ curricula around the world are continu-ally evolving: new discoveries, techniques, applications, andcontent areas compete for increasingly limited time with tra-ditional basic science topics such as gross anatomy. It is inthis context that the foundations established in grossanatomy become increasingly important and relevant forabsorbing and applying our ever-expanding knowledge ofthe human body. As a result of the progressively morecrowded curricular landscape, students and instructors arefinding new ways to maximize precious contact, preparation,and study time through more efficient, high-yield presenta-tion and study methods.

Clinical Anatomy for Your Pocket is designed to serve thetime-crunched student. The presentation of gross anatomyin bullet and table format streamlines study and exampreparation. This pocket size, quick reference book isportable, practical, and necessary; even at this small size,nothing is omitted and a large number of clinically signifi-cant facts, mnemonics, and easy-to-learn concepts are usedto complement the tables and inform the reader.

I am confident that Clinical Anatomy for Your Pocket willgreatly benefit all students attempting to learn clinically rel-evant anatomy in a variety of settings, including all graduateand professional gross anatomy programs.

iii

Preface

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I dedicate this book to my mother—Margaret.My first teacher.

iv

Dedication

I would like to thank the student reviewers for their inputinto this book: I hope that I have done you justice and cre-ated the learning tool that you need. I would also like tothank Dr. Robert DePhilip, the faculty reviewer of ClinicalAnatomy for Your Pocket, whose suggestions have provedinvaluable in creating an accurate and functional tool forstudents.

Acknowledgments

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Contents

v

Preface iiiDedication and Acknowledgments iv

1 Thorax . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Abdomen . . . . . . . . . . . . . . . . . . . . . 33

3 Pelvis . . . . . . . . . . . . . . . . . . . . . . . . 77

4 Back . . . . . . . . . . . . . . . . . . . . . . . 113

5 Lower Limb . . . . . . . . . . . . . . . . . . 126

6 Upper Limb . . . . . . . . . . . . . . . . . . 158

7 Head . . . . . . . . . . . . . . . . . . . . . . . . 196

8 Neck . . . . . . . . . . . . . . . . . . . . . . . . 237

List of Mnemonics 260Index 261

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Bone Characteristic SignificanceTypical ribs (3–9)

Atypical ribs (1–2, 10–12 )

Bones of the thoracic wall

Head

Neck

Tubercle

Body

• 1st and 2ndribs—heads

• Ribs 10–12sternalattachments

Bears 2 facets that articulate withvertebra of same number and thevertebra superior to it

Joins head with body of rib

• Articulates with transverse processof vertebra of same number

• Located at junction of neck and body

• Bears pronounced angle• Inferior internal border has costal

groove for intercostalneurovascular elements

• The heads of the first 2 ribs onlyattach to one vertebral body, unliketypical ribs that attach to two

• The 1st and 2nd ribs haveadditional tubercles for muscleattachments

INTRODUCTIONThe thorax is that portion of the trunk inferior to the neck(superior thoracic aperture) and superior to the diaphragm,to which the pectoral girdle and upper limbs are attached.

THORACIC WALLThe bones of the thoracic wall are the ribs and sternum.Ribs 3–9 possess characteristics common to the majority ofribs and so are considered “typical,” whereas ribs 1–2 and10–12 have specializations or are lacking typical characteris-tics and so are considered “atypical.”

1Thorax

1

(continued)

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2 CLINICAL ANATOMY FOR YOUR POCKET

Bone Characteristic Significance

Thoracic vertebrae (12)

Sternum

Bones of the thoracic wall (continued)

Body

Spinous process

Transverseprocess

Laminae andpedicles

Vertebralforamen

Vertebralnotches—superior andinferior

Articulatingprocesses—superior (2) andinferior (2)

Manubrium

Sternal angle

Body

Xiphoid process

• Ribs 10–12 attach indirectly (rib 10)or not at all to the sternum (ribs11–12, the floating ribs)

Supports weight

Serve for muscle attachments

Form vertebral arch that enclosesspinal cord

• Formed from vertebral arch andposterior aspect of vertebral body

• Encloses spinal cord• Successive vertebral foramen form

vertebral canal

Inferior and superior notches ofadjacent vertebrae formintervertebral foramen that permitspassage of spinal nerves betweenthe vertebral canal and periphery

Form zygapophyseal joints witharticulating processes on adjacentvertebrae

• Superior part of sternum• Superior border bears jugular notch• Clavicular notches (2) are found on

each side of the jugular notch forarticulation with the clavicles

• Landmark for the 2nd ribs’ costalcartilage articulation with thesternum

• Marks articulation betweenmanubrium and body

Bears costal notches along lateralborder for articulation with costalcartilages

• Most inferior part of sternum• Landmark for central tendon of

diaphragm, superior margin of liver,and inferior border of heart


Additional ConceptTrue, False, and Floating RibsRibs 1–7 are considered “true” ribs, as they attach to thesternum via their individual costal cartilages; ribs 8–10 areconsidered “false” ribs, as they attach indirectly to the ster-num via the costal cartilages of more superior ribs; ribs11–12 are considered “floating” ribs, as they do not connectto the sternum.

Clinical SignificanceRib FractureFracture of the upper ribs may injure the lungs and of lowerribs may damage the liver or spleen or may tear thediaphragm. All rib fractures are painful owing to the brokenpieces moving during respiration, coughing, sneezing, orlaughing.

Sternal PunctureA wide-bore needle may be used to harvest bone marrowfrom the sternum for transplantation or biopsy.

CHAPTER 1 | THORAX 3

Proximal DistalMuscle attachment Attachment Innervation Main ActionsExternal Inferior Superior Intercostal Elevate ribsintercostal aspect of ribs aspect of ribs nerves

Internal Depress andinter- elevate ribscostal

Innermostintercostal

Transverse Posterior inferior Posterior Depress ribsthoracic aspect of aspect of

sternum costal cartilages 2–6

Subcostal Deep aspect of Superior Depress andlower ribs, near aspect elevate ribsangles of 2–3 ribs

below proximal attachment

Muscles of the thoracic wall(Figures 1-2 and 1-4)

(continued)



Muscles of the thoracic wall (continued)

Diaphragm Sternum, Central Motor: Increases inferior 6 ribs tendon of phrenic; the volumeand their costal the diaphragm sensory: of the thoraxcartilages, medial phrenic and to cause& lateral arcuate intercostal inspirationligaments, and nerves1st 3 lumbar vertebrae

Levator T7–T11 Subjacent ribs C8–T11 Elevate ribscostarum transverse between posterior

processes tubercle and ramiangle

Serratus Nuchal ligament, 2nd–4th ribs 2nd–5th posterior C7–T3 spinous superior intercostalssuperior processes borders

Serratus T11–L2 spinous 8th–12th ribs 9th–11th Depress ribsposterior processes inferior borders, intercostalsinferior near angles and subcostal

Lung

Visceral pleura

Parietal pleura

Innermost intercostalmuscleIntercostal vein,artery, nerve

Internal intercostal muscleExternal intercostal muscle

Needle

Tube

Pleural cavity

FIGURE 1-1. Thoracocentesis. An intercostal nerve block (needle

in image) produces anesthesia of an intercostal space by introduc-

tion of an anesthetic agent around the intercostal nerve and its col-

laterals. The tube in the diagram indicates the position for thoraco-

centesis. (From Dudek RW, Louis TM. High-Yield Gross Anatomy.3rd ed. Baltimore: Lippincott Williams & Wilkins; 2008:56.)

Proximal DistalMuscle attachment Attachment Innervation Main Actions



Additional ConceptDiaphragmThe diaphragm has three openings that permit passage ofstructures between the thorax and abdomen. These open-ings are found at T8—caval foramen, T10—esophageal hia-tus, and T12—aortic hiatus.

Clinical SignificancePhrenic Nerve InjuryPhrenic nerve injury results in hemiparalysis of thediaphragm and paradoxical movement during inspiration.Instead of descending during inspiration, the paralyzedhalf ascends in response to increased intra-abdominalpressure.

Sternum

T8

T10

T12

Superiormesenteric artery

Celiac trunk

Aorta

Esophagus

Inferiorvena cava

Diaphragm

FIGURE 1-2. Holes in diaphragm. There are three large aper-

tures in the diaphragm for major structures to pass to and from

the thorax into the abdomen. The caval opening for the inferior

vena cava (IVC), most anterior, is at the T8 level and to the right

of the midline; the esophageal hiatus, intermediate, is at T10 and

to the left of the midline; the aortic hiatus for the aorta passes

posterior to the vertebral attachment of the diaphragm in the

midline at T12. (From Moore KL, Dalley AF. Clinically OrientedAnatomy. 5th ed. Baltimore: Lippincott Williams & Wilkins;

2006:329.)



Artery Origin Description

Internal Subclavian Gives rise to anterior intercostals and thoracic musculophrenic

Anterior Internal Supplies intercostal muscles and intercostals thoracic (1–6) and parietal pleura

musculophrenic (7–9)

Posterior Supreme intercostalintercostals (1–2) and thoracic aorta

Subcostal Thoracic aorta Supplies anterolateral abdominalmusculature

Arterial supply of the thoracic wall(Figures 1-1 and 1-4)

Nerve Origin Structures Innervated

Nerves of the thoracic wall(Figures 1-1 and 1-4)

Intercostals Anterior rami Intercostal muscles and parietal pleuraof T1–T11

Subcostal Anterior Abdominal wall musculature and rami of T12 parietal pleura

Rami Connect • White—convey presynapticcommunicantes intercostals sympathetic fibers from spinal nerve

and subcostal to sympathetic chain and visceralnerves to afferents to spinal nervessympathetic • Gray—convey postsynaptictrunk sympathetic fibers from the

sympathetic chain to spinal nerve

Sympathetic Sympathetic Composed of sympathetic gangliatrunk chain ganglia containing postsynaptic sympathetic

(paravertebral cell bodies connected by ascendingganglia) and descending fibers

Thoracic Sympathetic Convey presynaptic sympathetic fiberssplanchnics chain: to the prevertebral ganglia of the

• Greater— abdomen; convey visceral afferents to T5–T9 the sympathetic chain

• Lesser—T10–T11

• Least—T12


Additional ConceptVenous DrainageVenous drainage of the thoracic wall generally parallels arte-rial supply. However, the posterior intercostal veins drain tothe azygos system, which is discussed with the posteriormediastinum.


Joint Type Articulation Structure

1st Cartilaginous 1st costal Joint strengthened by sternocostal cartilage sternocostal radiate

with manubrium ligaments

2nd–7th Synovial 2nd–7th costal sternocostal cartilages with

sternum

Sternoclavicular Synovial Sternal end of • Divided into twoclavicle with compartments bymanubrium and articular disc1st costal cartil- • Joint strengthened age by anterior and

posterior sternoclavi-cular and costoclavi-cular ligaments

Manubriosternal Cartilaginous Manubrium with Joint often fuses inbody of sternum older people

Xiphisternal Xiphoid process with body of sternum

Interchondral • 6th–9th: Costal cartilages Strengthened bysynovial of adjacent ribs interchondral

• 9th–10th: 6–10 ligamentsfibrous

Costochondral Cartilaginous Costal cartilage • Bound together bywith end of rib periosteum

• Little if any movement permitted

Intervertebral Symphysis Adjacent verte- Strengthened by bral bodies anterior and posterior

longitudinal ligaments and the anular ligament

Joints of the thoracic wall

(continued)


BREASTThe breast extends from the sternum to the midaxillary lineand from ribs 2–6. It rests on the pectoral fascia and the fas-cia over serratus anterior.



Joints of the thoracic wall (continued)

Costovertebral Synovial Head of ribs with • Strengthened byvertebral bodies radiate and intra-at same level articular ligamentsand the • 1st, 11th, 12th, andvertebral body and sometimes 10th superior to it ribs articulate only

with vertebral body of same level

Costotransverse Tubercle of rib • Strengthened by with transverse lateral and superiorprocess of costotransverse vertebral body ligamentsat same level • 11th and 12th ribs do

not participate in costotransverse joints

Structure Description SignificanceMammary • Modified sweat glands • Accessory reproductive glands • Arranged in 15–20 lobules organs in the female

• Contained within thebreast

Areola • The skin around the nipple • Turns a darker color• Studded with sebaceous during pregnancy

glands that form eleva- • Stimulation from thetions suckling infant triggers

ejection and production of milk—the let-down reflex

Nipple • Round, raised area of skin Stimulation from the sucklingin the center of the areola infant triggers erection of

• Surrounded by circularly the nipple and the ejectionarranged smooth muscle and production of milkfibers that cause erection on stimulation

Structure of the breast(Figure 1-3)

(continued)


Additional ConceptThe size and shape of the adult female breast is due to itscontained fat, which forms the bulk of the breast tissue.


Structure Description Significance

Structure of the breast (continued)

Suspensory Connective tissue supports • Provide support for theligaments that extend from the dermis breast

to the pectoral fascia • If invaded by carcinoma, the ligaments shorten and produce skin dimpling and nipple inversion

Lactiferous duct 15–20 total, open onto Drain the mammary glandularthe nipple tissue

Lactiferous sinus Expansion of lactiferous duct Function as a milk reservoir near the nipple during lactation

Axillary process Extension of breast tissue High percentage of breast into the axilla tumors occurs here

Externalabdominal

oblique

Serratusanterior

Axillary tail

Areola

Nipple

Lactiferous ducts

Lactiferous sinusLobes Fat

FIGURE 1-3. Breast, anterior view. (From Tank PW, Gest TR.

LWW Atlas of Anatomy. Baltimore: Lippincott Williams & Wilkins;

2009:39.)


Additional ConceptVenous drainage of the breast parallels the arterial supplyand drains mainly to the axillary vein, whereas some venousdrainage is to the internal thoracic vein.



Medial mammary Internal thoracic Supplies medial aspect of breastbranches

Anterior intercostals

Lateral mammary Lateral thoracic Supplies lateral aspect of breastbranches

Thoracoacromial Axillary Supplies breast through pectoral branches

Posterior Thoracic aorta Supplies lateral aspect of breast intercostals through lateral mammary branches

Arterial supply of the breast

Clinical SignificanceQuadrantsThe breast is divided into four quadrants for the anatomiclocation and description of pathologies. The inferior quad-rants are less vascular and, therefore, the preferred area forsurgical incisions when necessary.

Retromammary SpaceBetween the breast and the pectoral fascia is the retromam-mary space, which permits movement of the breast on thethoracic wall. Diminishment of this movement may indicatepathology.

Nerves of the breast


Anterior cutaneous Intercostal • Sensory to skin of breastbranches nerves 4–6 • Postsynaptic sympathetic fibers to

Lateral cutaneous the smooth muscle of the nipple and

branches blood vessels


Additional ConceptThe contralateral breast receives a significant amount oflymphatic drainage.

MISCELLANEOUSThoracic cavityThe thoracic cavity is bounded by the thoracic wall—a flexi-ble musculoskeletal cage. It is divided into 2 laterally placedpleural cavities and a central region—the mediastinum.Thethoracic cavity contains the heart, lungs, thymus, trachea,esophagus, and multiple neurovascular elements.


Lymphatic Structure Description DrainageSubareolar Located deep to the nipple, Drains lymph from the nipple,lymphatic areola, and around the areola, and glandular tissueplexus lobules of the glandular of the breast to regional nodes

tissue of the breast

Axillary Composed of pectoral, Drains �75% of lymph from lymph nodes humeral, subscapular, the breast—the lateral

central, and apical nodes quadrant in particular

Parasternal Located along the sternum Drains mostly lymph from lymph nodes the medial quadrant of the

breast

Abdominal Located inferior to the dia- Drains mostly lymph from thelymph nodes phragm in the abdominal inferior quadrants of the breast

cavity; also known as inferior phrenic lymph nodes

Infraclavicular Located inferior to the Drains lymph from the axillarylymph nodes clavicle lymph nodes

Supraclavi- Located superior to the cular lymph claviclenodes

Subclavian Formed from efferent vessels • On the right—joins withlymphatic of the axillary nodes, apical bronchomediastinal & trunk in particular jugular trunks to form

the right lymphatic duct• On the left—joins the

thoracic duct

Lymphatics of the breastKnowledge of the lymphatic drainage of the breast is impor-tant owing to the high incidence of breast carcinoma.


Area Structure SignificanceSuperior Boundaries: • Also known as the thoracicthoracic • Anterior—manubrium inletaperture • Posterior—T1 • Allows passage of the

• Lateral—1st ribs and their trachea, esophagus, andcostal cartilages neurovascular elements

between the thoracic cavity and the neck

Inferior Boundaries: • Also known as the thoracicthoracic • Anterior—xiphisternal outletaperture joint • Closed by the diaphragm

• Anterolateral—costal • Allows for passage of cartilages of ribs 7–10— the inferior vena cava, aorta,the costal margin and esophagus between the

• Posterior—T12 thoracic cavity and abdomen• Posterolateral—11th and

12th ribs

Intercostal Space between adjacent ribs Contains intercostal musclesspace and costal cartilages and intercostal neurovascular

elements

Superior • Superior border—superior Contains superior vena cava,mediastinum thoracic aperture brachiocephalic veins, arch of

• Inferior border—plane aorta, thoracic duct, esophagus,passing from sternal angle trachea, left & right vagusthrough the T4–T5 nerves, left recurrent laryngealvertebral level nerve and left & right phrenic

• Lateral borders—pleural nerves, and the thymuscavities

Inferior • Superior border—plane Subdivided by the pericardial mediastinum passing from sternal angle sac into anterior, middle, and

through the T4–T5 posterior mediastinavertebral level

• Inferior border—diaphragm• Lateral borders—pleural

cavities

Anterior • Most anterior part of the Contains the thymus, loose mediastinum inferior mediastinum connective tissue, sternoperi-

• Bounded anteriorly by the cardial ligaments, lymphsternum and transverse nodes, and fatthoracic muscle and post-eriorly by the pericardium

Middle Middle part of inferior Contains the heart, pericardialmediastinum mediastinum sac, roots of the great vessels,

arch of the azygos vein, and primary bronchi

Posterior Most posterior part of the Contains the thoracic aorta,mediastinum inferior mediastinum esophagus, azygos and

hemiazygos veins, vagus nerves, thoracic duct, sympathetic trunks, and splanchnic nerves

12

Thoracic cavity (continued)


MnemonicV-A-N: Intercostal neurovascular elements are arrangedfrom superior to inferior as:

intercostal Veinintercostal Arteryintercostal Nerve

Clinical SignificanceThoracic Outlet SyndromeObstructions in the root of the neck may affect structurespassing through the superior thoracic aperture; problems areoften manifested in the upper limb.


Structure Significance

Organ

Esophagus • Located posterior to the trachea, anterior to vertebral bodies• Begins at inferior aspect of pharynx (C6)• Terminates by entering the stomach after passing through the

esophageal hiatus (T10) of the diaphragm

Nerve

Esophageal • Formed of parasympathetic fibers from the vagus nerves andplexus sympathetic fibers from sympathetic chain ganglia and the

greater splanchnic nerve• Supply glands and musculature of inferior 2/3 of esophagus

Sympathetic • Located on either side of the vertebral column along posterior trunks wall of the thorax

• Chain of paravertebral ganglia containing presynaptic sympathetic cell bodies

• Ganglia connected by presynaptic sympathetic and visceral afferent fibers

• Connected to thoracic spinal nerves by rami communicantes

Thoracic • Greater, lesser, and leastsplanchnic • Convey presynaptic sympathetic fibers from T5–T12nerves to prevertebral ganglia of the abdomen

• Convey visceral afferents from the abdomen

Vessel

Thoracic • Continuation of the arch of the aorta; becomes abdominal aorta aorta after passing through the aortic hiatus (T12) of the

diaphragm• Found to the left of thoracic vertebral bodies

Posterior mediastinum

(continued)


Clinical SignificanceEsophageal ConstrictionsThree constrictions of the esophagus occur where it is compressed by, from superior to inferior: (1) arch of theaorta, (2) left main bronchus, and (3) the diaphragm.These constrictions are areas susceptible to damage from swallow-ing caustic substances and are places where ingested objects



Posterior mediastinum (continued)

Bronchial • Left: branches of thoracic aortaarteries • Right: branches of posterior intercostal arteries

• Supply oxygenated blood to the tissues of the lung

Pericardial • Branches of thoracic aorta and pericardiophrenic arteriesarteries • Supply the pericardium

Posterior • Branches of thoracic aortaintercostal • Supply intercostal spaces 3–11arteries—9 pairs

Superior • Branches of the thoracic aortaphrenic • Supply the diaphragmarteries

Esophageal • Branches of the thoracic aortaarteries • Supply the esophagus

Subcostal • Branches of the thoracic aortaarteries • Supply body wall inferior to the 12th ribs

Thoracic • Conveys lymph from entire body, except the right upper limb,duct right aspect of the thorax and right side of head & neck

• Begins in abdomen at chyle cistern and empties into the junction of left internal jugular vein and left subclavian vein

• Found along the vertebral column between the azygos vein and esophagus

Azygos vein • Drains mediastinum and posterior thoracic & abdominal walls on the right; found on right side of vertebral bodies

• Begins in the abdomen and terminates by emptying into superior vena cava

• Receives hemiazygos and accessory hemiazygos veins at the T8–T9 vertebral level

Hemiazygos • Drains mediastinum and posterior thoracic and abdominal vein walls on the left as high as T9 vertebral level, where it

crosses to the right side to enter the azygos vein

Accessory • Drains mediastinum and posterior upper thoracic wall on the hemiazygos left as far inferiorly as T8 vertebral level where it crosses tovein the right side to enter the azygos vein

The trachea is presented with the superior mediastinum.


may become lodged; the constrictions are visible on radi-ographs and are useful landmarks.

Azygos VeinsThe azygos system provides a collateral pathway for venousblood that connects the superior and inferior vena cavae.

MnemonicFour birds of the thorax:

esophaGOOSEvaGOOSE nerve azyGOOSE veinthoracic DUCK


Sympatheticchain

Azygosvein

Rightprimary

bronchus

Intercostalvein, artery,

and nerve

Cut edgeof costal

pleura

Esophagus

Trachea

Leftprimarybronchus

Thoracicduct

Diaphragm

FIGURE 1-4. Posterior mediastinum viewed from the right: parietal

pleura is intact on left side and partially removed on right. A portion of

esophagus, between bifurcation of trachea and diaphragm, is also

removed. (From Agur AMR, Dalley AF. Grant’s Atlas of Anatomy, 12th

ed. Baltimore: Lippincott Williams & Wilkins; 2009:82.)



(continued)

Superior mediastinum(Figure 1-5)

Structure SignificanceLigamentum • Remnant of the ductus arteriosus (shunt for blood from the arteriosum fetal pulmonary trunk to aorta)

• Connects left pulmonary artery to the arch of the aorta• Left recurrent laryngeal nerve wraps around to then ascend to

the larynx

OrganThymus • Located mostly in the superior mediastinum

• Lymphatic organ that involutes after puberty and is replacedby fat

Trachea • Located anterior to the esophagus• Begins at cricoid cartilage of the larynx• Terminates at the level of the sternal angle into 2 main bronchi• Skeleton of posteriorly oriented U-shaped rings, posterior

deficiency spanned by the trachealis muscle

Esophagus • Located posterior to the trachea and anterior to the vertebralbodies

• Begins at inferior aspect of the pharynx, terminates by enteringthe stomach after passing through the esophageal hiatus (T10) of the diaphragm

NerveLeft vagus • Found anterior to the arch of the aorta where it gives off the

left recurrent laryngeal nerve• Passes posterior to the root of the lung, where it ramifies

to contribute to the pulmonary, cardiac, and esophageal plexuses

Right vagus • Found anterior to the right subclavian artery, where it gives off the right recurrent laryngeal nerve

• Passes posterior to the root of the lung, where it ramifiesto contribute to the pulmonary, cardiac, and esophageal plexuses

Left • Branch of left vagus nerve as it passes over the anterior recurrent surface of the arch of the aortalaryngeal • Ascends to the larynx between the trachea and esophagus

Right • Branch of the right vagus nerve as it passes over the anteriorrecurrent surface of the right subclavian arterylaryngeal • Ascends to the larynx between the trachea and esophagus in

the tracheoesophageal groove

Left phrenic • Passes anterior to the root of the lung, found between thenerve fibrous pericardium and mediastinal pleura

Right • Sole motor supply to the diaphragmphrenic • Sensory to central aspects of diaphragmnerve


Additional ConceptLymphatic DrainageIn addition to the brachiocephalic veins forming at the junc-tion of the internal jugular and subclavian veins, it is also thepoint where the right lymphatic duct joins the venous sys-tem on the right and the thoracic duct on the left—knownas the jugular angle.



Superior mediastinum (continued)

Vessel

Left • Formed by junction of the internal jugular and subclavian veinsbrachioce- • The left and right brachiocephalic veins join to form the phalic vein superior vena cava

Right brachioce-phalic vein

Superior Drains most venous blood from structures superior to the vena cava thorax into the right atrium

Arch of the • Continuation of the ascending aorta; becomes the thoracic aorta aorta as it descends

• Gives off 3 branches in the superior mediastinum:1. brachiocephalic trunk2. left common carotid artery3. left subclavian artery

• Left vagus nerve courses on its anterior surface

Brachioce- • 1st branch of the arch of the aortaphalic trunk • Terminates by dividing into the right common carotid and right

subclavian arteries• Indirectly supplies the right side of head and neck and right

upper limb through its branches

Left • 2nd branch of the arch of the aortacommon • Terminates in the neck by dividing into internal & external carotid carotid arteriesartery • Indirectly supplies left side of head and neck through its

branches

Left sub- • 3rd branch of the arch of the aortaclavian • Continues as it passes over the lateral border of the 1st rib toartery become the left axillary artery

• Supplies the left upper limb

The thoracic duct is presented with the posterior mediastinum.


MEDIASTINUMAdditional ConceptPericardiumThe pericardium receives its arterial supply from the peri-cardiacophrenic arteries, which run with the phrenic nervebetween the mediastinal pleura and the fibrous pericardium.Sensory innervation to the pericardium is carried via thephrenic nerves.


Structure Description SignificancePericardial Formed of 2 layers: • Double-layered fibroseroussac 1. outer—fibrous sac that encloses the heart

pericardium • Fused with adventitia of the2. inner—parietal layer of great vessels

serous pericardium • Attached to the deep surface of the sternum by the sterno-pericardial ligament

• Fuses with the central tendon of the diaphragm; therefore, moves during respiration

Visceral layer Mesothelium—simple Also known as the of serous squamous epithelium epicardium—the outer layer pericardium of the heart

Parietal layer Lines inner surface of fibrousof serous peri- pericardiumcardium

Pericardial Potential space between • Filled with serous fluidcavity the layers of serous peri- • Allows heart to beat in a

cardium friction free environment

Fibrous peri- • Strong collagenous outer • Inflexible nature preventscardium layer of the pericardial overfilling of the heart

sac • Phrenic nerve travels • Fuses with adventitia of inferiorly through the thorax

great vessels, central on its lateral surfacetendon of the diaphragm, and sternum

Transverse Extension of the pericardial Allows for control of blood out sinus cavity posterior to the pul- of the heart during surgery

monary trunk and aorta

Oblique sinus Extension of the pericardial Ends as a cul-de-sac betweencavity on the posterior the pulmonary veinsaspect of the heart

Structure of the pericardial cavity(Figure 1-5)



Clinical SignificancePericarditisInflammation of the pericardium that may cause chest painand pericardial friction rub, which can be detected duringauscultation.

Pericardial TamponadeAn increase in fluid in the pericardial cavity (e.g., fromchronic inflammation) may decrease the efficiency of theheart as it is compressed. Pericardiocentesis is the drainageof excess fluid from the pericardial sac.

Structure of the heart(Figure 1-6)

The heart is contained within the pericardial sac. It islocated within the middle mediastinum, left of the medianplane in the thorax. The heart is essentially a cone-shapedmuscular pump, the apex of which is directed anteroinferi-orly to the left and the base posterolaterally to the right.Thebase of the heart is the location of the superior vena cava,ascending aorta and pulmonary trunk.

Structure Description SignificanceHeart • Anterior (sternocostal) • Anterior—formed mainly by surfaces • Inferior (diaphragmatic) right ventricle

• Right and left pulmonary • Diaphragmatic—formedsurfaces mainly by left ventricle

(some right ventricle) related to central tendon of diaphragm

• Left pulmonary—formed mainly by left ventricle, related to cardiac notch of left lung

• Right pulmonary—formed mainly by right atrium

Pectinate Muscular ridges found on • Found in primitive parts of muscles the walls of the atria both atria

• Presence indicates “rough” part of atrial walls

Trabeculae Muscular ridges found on • Found in primitive parts of carneae the walls of the ventricles both ventricles

• Serve to increase mechanical advantage during ventricularcontraction

• Presence indicates “rough” part of ventricular walls

(continued)



Structure Description SignificancePapillary Conical muscular projections Contract immediately beforemuscles from the ventricular wall ventricular contraction to pull

that attach to chordae chordae tendineae taut to tendineae prevent backflow during

ventricular contraction (systole)

Chordae Attached to margins of Hold valve cusps taut duringtendineae atrioventricular valves and ventricular contraction to

papillary muscles prevent backflow (regurgitation)

Interatrial Muscular septum separating Right side—location of fossa septum the atria ovalis: remnant of foramen

ovale, an embryologic shunt for blood from the right atrium to the left atrium

Interventricular Composed of a membranous Separates right and left septum (superior) part and a muscular ventricles

(inferior) part

Right and • Right—3 cusps • Right—permits passage of left atrioventri- (tricuspid) blood from right atrium to cular valves • Left—2 cusps right ventricle and prevents

(bicuspid, mitral) backflow in the reverse direction

• Left—permits passage of blood from left atrium to left ventricle and prevents backflow in the reverse direction

Fibrous • Collagenous skeleton of • Provides stability and attach-skeleton heart ment for valve cusps and

• Forms fibrous rings that muscle fiberssurround heart orifices • Provides electrical insulation

• Fibrous trigones connect between the atria and rings ventricles

Right atrium Forms right border of heart Receives deoxygenated blood from the superior and inferior vena cavae & coronary sinus

Sinus venarum Smooth-walled part of right Formed from incorporation of atrium the embryonic sinus venosus

during development

Sulcus Groove on outside of right External representation of terminalis atrium meeting of primitive atrium and

sinus venarum derived tissues

Crista Ridge on inside of right Internal representation of terminalis atrium meeting of primitive atrium and

sinus venarum derived tissues

Structure of the heart (continued)

(continued)



Structure Description SignificanceRight auricle Small, conical projection Remnant of primitive right

from right atrium atrium

Left atrium Forms most of base of heart Receives oxygenated blood from 4 pulmonary veins

Left auricle Finger-like projection from Remnant of primitive left left atrium atrium

Right Forms inferior border of Receives blood from right ventricle heart atrium

Conus Smooth-walled superior Entry to the pulmonary trunkarteriosus aspect of right ventricle(infundibulum)

Supraventri- Muscular ridge on inside of Separates rough part of cular crest right ventricle chamber from smooth-walled

part of chamber

Septomarginal Muscular ridge that extends Conveys right atrioventricular trabecula from the inferior aspect of bundle—part of conduction (moderator the interventricular septum system, to the anterior band) to the base of the anterior- papillary muscle

most papillary muscle

Pulmonary • 3 semilunar cusps Prevents backflow valve • Located at apex of conus (regurgitation) of blood during

arteriosus ventricular relaxation (diastole)

Pulmonary Located between cup-shaped Prevent valve cusps from sinuses semilunar valve leaflets and sticking to pulmonary trunk

dilated pulmonary trunk wall wall during ventricular contraction

Left ventricle Forms apex and left border Thicker wall (4�) than right of heart ventricle because it pumps

against greater pressure

Aortic vesti- Smooth-walled superior Entry to ascending aortabule aspect of left ventricle

Aortic valve • 3 semilunar cusps Prevent backflow • Located near origin of (regurgitation) of blood during

ascending aorta ventricular relaxation (diastole)

Aortic sinuses Located between cup- • Prevent valve cusps from shaped semilunar valve sticking to ascending aorta leaflets and dilated ascend- wall during ventricular ing aorta wall contraction

• Right and left sinus give origin to the right and leftcoronary arteries respectively

Structure of the heart (continued)


Additional ConceptHeart is a “Double Pump”Right side of the heart: right atrium receives deoxygenatedblood from the vena cavae; the right ventricle pumps thisblood to the lungs for oxygenation via the pulmonary trunk.Left side of the heart: left atrium receives oxygenated bloodfrom the pulmonary veins; the left ventricle pumps thisblood to the body via the aorta.

Walls of the HeartThe walls of all 4 chambers of the heart consist of the samethree layers from superficial to deep:

epicardium—layer of mesothelium; also known as viscerallayer of serous pericardium

myocardium—middle layer composed of cardiac muscletissue

endocardium—layer of endothelium that lines heartchambers and valves


Right brachiocephalic vein

Left brachiocephalic veinSuperior vena cava

Reflection ofpericardium

Right auriclePectinatemuscles

Fossaovalis

Rightatrium

Inferiorvena cava

Tricuspid valvePapillary

muscle

Rightcoronary

artery

Left subclavian arteryLeft common carotid artery

Brachiocephalic trunkArch of aorta

Ligamentumarteriosum

Pulmonarytrunk

ConusarteriosusLeft auricle

Leftventricle

Abdominalaorta

Apex of heart

Muscularinter-ventricularseptum

Chordaetendineae

Moderatorband

Anterior inter-ventricularartery

FIGURE 1-5. Heart. Right interior view. (Asset provided by

Anatomical Chart Company.)


AuscultationAuscultation of the valves: each of the 4 valves of the heartis heard best at specific locations on the thoracic wall:

bicuspid valve—5th intercostal space on the lefttricuspid valve—4th intercostal space to the left of the

sternumpulmonary valve—2nd intercostal space to the left of the

sternumaortic valve—2nd intercostal space to the right of the

sternum

VentriclesVentricle characteristics—fewer, larger papillary muscles,more numerous trabeculae carneae, fewer, thicker atrioven-tricular valve cusps and fewer, thicker chordae tendineae arecharacteristics of the left ventricle owing to its increasedworkload relative to the right ventricle.

Clinical SignificanceForamen OvaleIncomplete closure of the foramen ovale occurs in15%–25% of adults, it is typically asymptomatic.

Septal DefectsThe membranous part of the interventricular septum isthe most common site of interventricular septal defects;severe defects may result in hypertension and cardiac failure.


Nerves of the heart

Nerve Origin Structures InnervatedSuperficial • Sympathetic— • Sympathetic—terminate on SA and cardiac plexus sympathetic AV nodes, increases heart rate and

trunks force of contraction, produces vasodi-• Parasym- lation of coronary arteries

pathetic—vagus • Parasympathetic—terminate on SA nerves and AV nodes and coronary arteries,

• Located inferior decreases heart rate and force ofto the aortic arch contraction, causes vasoconstrictionand anterior to of coronary arteriesthe right pulmo-nary artery

(continued)



Nerves of the heart (continued)

Nerve Origin Structures InnervatedDeep cardiac • Sympathetic—plexus sympathetic

trunks• Parasym-

pathetic—vagus nerves

• Located posterior to the aortic arch and anterior to the tracheal bifurcation

Visceral Fibers travel with • Fibers traveling with sympatheticsafferents of sympathetics and convey pain information to T1–T5 cardiac plexuses in the vagus nerve spinal cord segments; these fibers are

involved in pain referred to the left upper limb during heart attack

• Fibers traveling in the vagus nerve innervate baroreceptors and chemoreceptors that monitor pressureand gas concentrations in the blood

Sinuatrial (SA) Group of self- Pacemaker of the heart, gives an node excitable cardiac impulse ~70 times per minute

muscle cells located near the junction of the superior vena cava and the right atrium

Atrioventricular Located on the • Receives impulse from wall of atria(AV) node right side of the that was initiated in the SA node

atrial septum near • Passes impulse to ventricles via the the opening of the AV bundlecoronary sinus

AV bundle Fiber bundle pass- Only bridge of conduction system(Bundle of His) ing from the AV between atria and ventricles

node to membran-ous part of inter-ventricular septum, where it terminates by dividing into bundle branches

Right and left Formed by termina- • Supply cardiac muscle cells ofbundle branches tion of AV bundle, ventricular walls through ramifications

follow interventri- (subendocardial branches)cular septum to • Right bundle branch sends a branchventricular walls through the septomarginal trabeculaewhere they ramify of the right ventricle to the anterior

papillary muscle


Additional ConceptPostsynaptic parasympathetic ganglia are located near theSA and AV nodes.


Vessels of the heart

Artery Origin DescriptionRight coronary Right aortic Supplies right atrium & ventricle, left

sinus ventricle, SA and AV nodes, and inter-ventricular septum

SA nodal branch Right coronary Supplies SA node

Right marginal artery Supplies right ventricle and apex of branch heart

Posterior Supplies both ventricles and posterior interventricular aspect of interventricular septum

AV nodal branch Supplies AV node

Left coronary Left aortic sinus Supplies left atrium and ventricle, right ventricle, and interventricular septum

Anterior interven- Left coronary Supplies right and left ventricles andtricular (left artery interventricular septumanterior descending

Left circumflex Supplies left atrium and ventriclebranch

Left marginal Left circumflex Supplies left ventriclebranch branch

Posterior interven- Left coronary Supplies interventricular septumtricular branch artery

Vein Termination DescriptionCoronary sinus Right atrium Large vein on posterior aspect of heart

in coronary sulcus; accepts most venousblood from the heart before emptying into right atrium

Great cardiac Coronary sinus Runs with anterior interventricular artery in anterior interventricular sulcus;becomes coronary sinus on posterior aspect of heart

Middle cardiac Runs with posterior interventricular artery in posterior interventricular sulcus

Small cardiac Runs with right marginal branch

Oblique vein of Remnant of primordial left superior left atrium vena cava

Left posterior Drains posterior aspect of left ventricleventricular

Left marginal Drains left margin of heart

Anterior cardiac Right atrium Drains right ventricle

Smallest cardiac Chambers of Drains walls of all 4 chambers of heartheart


Additional ConceptVenous DrainageVenous drainage of the heart is said to be “indirect” becausemost venous blood enters the coronary sinus before beingemptied into the right atrium.

Clinical SignificanceCoronary ArteriesCoronary artery disease is a leading cause of death, typicallyas a result of decreased blood flow to the heart. An area ofmyocardium that has undergone necrosis (as a result of lackof blood) constitutes a myocardial infarction or heart attack.

LUNGS AND PLEURA


Structure Description SignificanceEndothoracic Fibroareolar layer between Invests muscular and skeletalfascia parietal pleura and thoracic elements of thoracic wall and

wall adheres parietal pleura to inner surface of thoracic wall

Costal pleura Parietal pleura adherent to Intercostal and phrenic nervesthe inner surface of the ribs provide sensory innervation; and costal cartilages via the therefore, pain may be referred endothoracic fascia to the thoracic wall and neck

Mediastinal Parietal pleura adherent topleura the outer surface of the

mediastinum via the endothoracic fascia

Diaphragmatic Parietal pleura adherent topleura the superior surface of the

diaphragm via the endotho-racic fascia

Cervical pleura • Parietal pleura extending into the root of the neck

• Covered by the supra-pleural membrane—a regional thickening of the endothoracic fascia

Pulmonary Double-layered fold of pleura Area of reflection—visceralligament extending inferiorly from the pleura from the surface of

root of the lung the lung is continuous with parietal pleura

Structure of the pleural cavities(Figures 1-4, 1-6 and 1-7)

(continued)




Structure of the pleural cavities (continued)

Visceral pleura Covers all surfaces of each • Continuous with parietal lung pleura at the root of the

lung• No or very limited pain

afferents

Pleural cavity Potential space between the • Contains capillary layer of visceral and parietal pleura serous fluid

• Negative pressure here maintains lungs in inflated state

Left and right Potential space between During inspiration the lungscostodiaphrag- costal and diaphragmatic enter the recessesmatic recesses pleura

Left and right Potential spaces betweencostomediastinal costal and mediastinalrecess pleura

IVC andpericardium

Pericardium

Left ventricle

Pulmonary trunk

Right atrium

Superiorvena cava

FIGURE 1-6. Anteroposterior chest radiograph. Radiograph

shows the various components of the heart and great vessels. (From

Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore:

Lippincott Williams & Wilkins; 2008:85.)


Clinical SignificanceCervical PleuraThe cervical pleura and apex of the lung are subject toinjury from neck wounds because the pleural cavity extendsinto the root of the neck.


FIGURE 1-7. Pneumothorax. A pneumothorax is air in the plural

cavity; this has the effect of collapsing the elastic lung as the negative

pressure maintaining it in its expanded state is lost. Posteroanterior

radiograph shows a left apical (straight arrows) and subpulmonic

(curved arrow) pneumothorax in a 41-year-old woman with respira-

tory distress syndrome. (From Dudek RW, Louis TM. High-YieldGross Anatomy. 3rd ed. Baltimore: Lippincott Williams & Wilkins;

2008:64.)


Tracheal rings 20 U-shaped hyaline • Keep trachea patentcartilages • Posteriorly oriented opening

of U-shaped cartilage allowsfor expansion of the esoph-agus during swallowing

Tracheobronchial tree(Figure 1-4)

(continued)




Tracheobronchial tree (continued)

Trachealis Layer of smooth muscle Spans posterior deficiency of tracheal rings

Right and left • Extend from tracheal bifur- • Form part of root of the lungmain bronchi cation to hilum of lungs • Enter lung at hilum

• Supported by U-shaped • Right main bronchus is shor-hyaline cartilage ter, wider and more vertically

• Terminate by dividing into oriented than the leftlobar bronchi • Hyaline cartilage keeps both

main bronchi patent

Carina Keel-like septum projecting Visible on radiographs; superiorly at the bifurcation displacement may indicate of the trachea thoracic pathology

Lobar (secondary) • Supported by hyaline • Hyaline cartilage keeps bronchi (3; right) cartilage lobar bronchi patent

Lobar (secondary) • Extend from main bronchi • Each lobar bronchus

bronchi (2; left) until termination as seg- corresponds to a lobemental bronchi of the lung

Segmental • Supported by hyaline • Supply bronchopulmonary (tertiary) bronchi cartilage segments—right lung: 10

• Formed from terminal segmental bronchibranches of lobar bronchi • Left lung: 8–10 segmental

bronchi

Bronchopulmo- Pyramidal-shaped with • Each receives a segmental nary segments apex directed toward root of bronchus and a branch of

lung and base toward outer both pulmonary andsurface of lung bronchial arteries

• Intersegmental veins help identify boundaries between segments for resection

Additional ConceptBronchopulmonary Segments

■ Right lung—Superior lobe: Apical, Posterior, AnteriorMiddle lobe: Lateral, MedialInferior lobe: Superior, Anterior basal, Posterior basal,Lateral basal, Medial basal

■ Left lung—Superior lobe: Superior division—Apicoposterior,Anterior; Lingular division—Superior, Inferior

Inferior lobe: superior, Anterior basal, posterior basal,Lateral basal, Medial basal




Right lung 3 lobes (superior, middle, The right lung is larger than and inferior) separated by the lefta horizontal and oblique fissure

Left lung 2 lobes (superior and inferior) The left lung is smaller thanseparated by an oblique the right owing to the positionfissure of the heart

Cardiac notch Indentation of superior lobe Result of the heart and of left lung along the pericardial sac bulging to theanteroinferior border left

Lingula Tongue-like process of superior lobe of the left lung inferior to the cardiac notch

Root of lung • Formed by pulmonary and Located on medial aspect of bronchial arteries, pulmo- lung, site at which structuresnary and bronchial veins, enter and leave the lunglymphatics, nerves, and main bronchi

• Enclosed by pleural sleeve

Hilum of lung Located on medial aspect of Root of lung enters lung herelungs

Horizontal and • Right lung has 1 horizontal Separate lungs into lobes:oblique fissures and 1 oblique fissure right lung 3, left lung 2

• Left lung has 1 oblique fissure

MnemonicInhale a Bite, Goes Down the Right Inhaled objects more likely to enter right bronchus, as it iswider, shorter, and more vertical than the left.

Structure of the lungsThe lungs are the elastic organs of respiration. Their function depends upon surface tension in the pleural cavity keeping the parietal and visceral layers of pleuratogether.


Additional ConceptPostsynaptic parasympathetic ganglia are found distributedthroughout both plexuses.


Nerves of the lungs


Anterior • Sympathetic— • Sympathetic—inhibit bronchialpulmonary plexus sympathetic smooth muscle (bronchodilate) and

trunks glands, motor to vessels • Parasym- (vasoconstrict)

pathetic—vagus • Parasympathetic—inhibit vessel nerves musculature (vasodilate), motor to

• Located anterior smooth muscle of bronchial tree to root of lung (bronchoconstrict) and glands

(stimulates mucous secretion)

Vessels of the lungs


Right and left Pulmonary Give rise to lobar arteries; carrypulmonary trunk deoxygenated blood to the lungs

Lobar Pulmonary 3 right and 2 left lobar arteries carry arteries deoxygenated blood to each lobe of the

lung; accompany secondary bronchi

Right and left • Right— Supply oxygenated blood to the tissuesbronchial posterior of the bronchial tree

intercostal artery

• Left—thoracic aorta

Vein Termination DescriptionRight and left Left atrium 2 pairs of pulmonary veins convey pulmonary oxygenated blood to the left atrium

(continued)

Posterior • Sympathetic—pulmonary plexus sympathetic

trunks• Parasym-

pathetic—vagus nerves

• Located posterior to root of lung

Visceral afferents Fibers travel in Sensory to tissues of the lungs andof pulmonary vagus nerve bronchi—touch, stretch, temperature,plexuses and chemical irritants


Additional ConceptThe superficial and deep lymphatic plexuses of the lungscommunicate freely.

Clinical SignificanceBronchopulmonary nodes are an early site of tumormetastases in bronchogenic carcinoma.

Additional ConceptLigamentum ArteriosumThe ligamentum arteriosum is the remnant of the ductusarteriosus—an embryologic shunt connecting the arch ofthe aorta and the left pulmonary artery.


Lymphatic structure Description Drainage

Superficial Located immediately deep to Drains to bronchopulmonary lymphatic plexus visceral pleura lymph nodes

Deep lymphatic Located in the submucosa of Drains to pulmonary lymph plexus bronchi and connective nodes

tissue around the bronchi

Pulmonary Located along the lobar Drain to bronchopulmonary lymph nodes (secondary) bronchi lymph nodes

Bronchopul- Located in the hilum of the Drain to tracheobronchialmonary (hilar) lung(s) lymph nodeslymph nodes

Superior and Located at the bifurcation of Drain to bronchomediastinal inferior tracheo- the trachea trunks (right and left)bronchial lymph nodes

Lymphatics of the lungs

Vessels of the lungs (continued)

Vein Termination Description

Right and left • Right— Drain deoxygenated blood from the bronchial azygos vein bronchial tree

• Left—accessory hemiazygos vein


INTRODUCTIONThe abdomen is that portion of the trunk inferior to thediaphragm and superior to the pelvis with which it is con-tinuous. The abdomen extends inferiorly to the superiorpelvic aperture.

AREAS AND FASCIA OF THE ABDOMEN

2Abdomen

33

Area Structure SignificanceAbdominal cavity

Regions (9)

Areas of the abdomen

Boundaries:

• Superior—diaphragm

• Inferior—continuous withpelvic cavity atsuperior pelvicaperture

• Anterolateral—muscular abdominalwall

• Posterior—vertebral column

Divided into regionsby:

• 2 horizontalplanes—subcostaland transtubercular

• 2 vertical-midclavicularplanes

Larger, superior part of theabdominopelvic cavity

• Regions: • Right and left

hypochondriac• Right and left inguinal• Right and left lateral• Epigastric• Umbilical• Pubic

• Used for description oforgan location or locationof pathologic processes

(continued)



Area Structure SignificanceQuadrants (4)

Inguinal canal

Subinguinal space

Areas of the abdomen (continued)

Divided intoquadrants by ahorizontal(transumbilical) and avertical (median)plane

• 4–6 cm long,inferomediallydirected passageextending betweenthe deep andsuperficial inguinalrings

• Walls of canal: • Anterior—

external obliqueaponeurosis

• Posterior—transversalisfascia andmedially theconjoint tendon

• Roof—transversalisfascia and archingfibers of theinternal obliqueand transversusabdominis

• Floor—iliopubictract, inguinalligament, andlacunar ligamentfrom lateral tomedial

Space located deep tothe inguinal ligamentand iliopubic tract

• Quadrants: • Right and left upper• Right and left lower

• Used for description oforgan location or locationof pathologic processes

• Transmits the spermaticcord or round ligament ofthe uterus, ilioinguinalnerve, and the genitalbranch of thegenitofemoral nerve

• One result of the obliquenature of canal is that thesuperficial and deep ringsdo not overlap; therefore,increases in intra-abdominal pressure forcethe canal “closed” toprevent herniation

Serves to connect theabdominopelvic cavity withthe lower limb

Additional ConceptsDeep Inguinal RingThe deep inguinal ring, the internal opening of the inguinalcanal, is an evagination of transversalis fascia, just superiorto the middle of the inguinal ligament and immediately lat-eral to the inferior epigastric vessels.


Superficial Inguinal RingThe superficial inguinal ring is the slitlike external open-ing of the inguinal canal in the aponeurosis of the externaloblique muscle, just superior to the public tubercle. Themedial and lateral margins of the opening are the medialand lateral crura, which are prevented from spreadingapart by intercrural fibers.

CHAPTER 2 | ABDOMEN 35

Feature DescriptionSuperficial fascia

Investing fascia

Endoabdominal fascia

Parietal peritoneum

Rectus sheath

Structures of the abdominal wall

Inferior to umbilicus, it is composed of 2 layers: • A superficial fatty layer (Camper’s fascia)• A deep membranous layer (Scarpa’s fascia)

Covers the muscles (4) forming the muscular wall ofthe abdomen

• Lines inner surface of abdominal wall• Named according to muscle it lines:

• Transversalis fascia lines the transverseabdominal muscle• Divided into anterior, middle, and posterior

layers• Middle and posterior layers enclose the

intrinsic muscles of the back—relativelythick, provides attachment for anterolateralabdominal wall muscles

• Anterior layer is fascia of quadratuslumborum muscle—thickened superiorly toform lateral arcuate ligament, inferiorlyattaches to iliolumbar ligament

• Lumbar fascia lines the quadratus lumborum• Psoas fascia lines the psoas major muscle

• It is thickened superiorly to form the medialarcuate ligament

• It is continuous with the thoracolumbarfascia

• Lines abdominopelvic cavity• Located deep to the endoabdominal fascia

from which it is separated by extraperitoneal fat

• Formed by the aponeuroses of the external andinternal oblique and transverse abdominal

• The sheath contains the rectus abdominis, the superior and inferior epigastric vessels, the pyramidalis, segmental nerves, andlymphatics

(continued)


Additional ConceptRectus SheathRectus sheath—Above a line midway between thepubic symphysis and umbilicus the anterior layer of thesheath is formed by the external oblique and the ante-rior portion of the internal oblique, which splits to con-tribute to the posterior layer of the sheath with thetransverse abdominal muscle. Below this line, thesheath is deficient posteriorly, with the aponeurosis ofall three muscles forming the anterior layer of thesheath, with only the transversalis fascia separating therectus abdominis from the parietal peritoneum. Thelower edge of the aponeurotic “line” of the posteriorsheath is the arcuate line.


Feature Description

Conjoint tendon

Inguinal ligament

Iliopubic tract

Lacunar ligament

Pectineal ligament

Structures of the abdominal wall (continued)

• Fused tendons of internal oblique and transverseabdominal at their attachment to the pubis

• Forms medial portion of posterior wall of inguinalcanal

• Free, fibrous inferior edge of external oblique,extending between the anterior superior iliacspine and pubic tubercle

• Laterally provides attachment for transverseabdominal and internal oblique

• Thickened inferior margin of the transversalisfascia

• Forms portion of floor and posterior wall ofinguinal canal

• Located posterior and parallel to the inguinalligament

• Forms the anterior boundary of the subinguinalspace

• Medial-most internally directed portion of theinguinal ligament

• Forms portion of floor of inguinal canal• Attaches to superior pubic ramus

Continuation of lacunar ligament as it runs alongthe pectin pubis



Proximal Distal Muscle Attachment Attachment Innervation Main ActionsAnterolateral Abdominal WallExternal oblique

Internal oblique

Transverse abdominal

Rectus abdominis

Pyramidalis

Spermatic Cord and ScrotumCremaster

Dartos

Posterior Abdominal WallPsoas minor

Muscles of the abdominal wall

Ribs 5–12

Thoracolumbarfascia,anterior iliaccrest, inguinalligament

Costalcartilages7–12,thoracolumbarfascia, iliaccrest, inguinalligament

Pubicsymphysis andpubic crest

Pubis

T12–L1vertebrae andintervertebraldiscs

Linea alba,pubic crestandtubercle,anterior iliaccrest

Ribs 10–12,linea alba,pectin pubis(via conjointtendon)

Linea alba,pubic crest,pectin pubis(via conjointtendon)

Xiphoidprocess,costalcartilages5–7

Linea alba

Pectin pubis

T5–T12

T6–T12 andL1

T6–T12

T12

Genitofemo-ral

Autonomic

L1

Compress,protect, andsupportabdominalcontents; flexand rotatetrunk

Compress,protect, andsupportabdominalcontents

Compress,protect, andsupportabdominalcontents; flextrunk (lumbarregion)

Tenses lineaalba

Draws testescloser to body

Wrinkles skinof scrotum

Weak trunkflexor; oftenabsent

Found within cremaster fascia

Found within superficialfascia of scrotum

ABDOMINAL WALL

(continued)



Skeletal elements (attachments) discussed above are presentedwith the thorax and pelvis.

Clinical SignificanceGuarding ReflexIn addition to the functions mentioned previously, the flatabdominal wall muscles provide protection to abdominalviscera through involuntary contraction when touched orwhen an underlying structure is inflamed, becoming rigid;this is known as the “guarding” reflex.

MnemonicsOrientationHands-in-your-pockets orientation:

When you put your hands in your pants pockets, your fin-gers have the orientation of fibers of the externaloblique inferomedially.

Internal oblique fibers are at right angles to externaloblique fibers.

Psoas MajorInnervation of psoas major: Hitting L2, L3, and L4 makesthe psoas sore.

Vessels of the abdominal wall

Artery Origin DescriptionMusculophrenic Internal thoracic Supplies: diaphragm, anterolateral

Superior epigastric abdominal wall

Inferior epigastric External iliac Supplies: rectus abdominis, antero-lateral abdominal wall

(continued)

Proximal Distal Muscle Attachment Attachment Innervation Main ActionsPsoas major

Iliacus

Quadratus lumborum

Muscles of the abdominal wall (continued)

T12–L5vertebrae andintervertebraldiscs

Iliac fossa

12th rib

Lessertrochanterof femur

Iliolumbarligament andiliac crest

L2–L4

Femoral

T12–L4

Together formiliopsoas—thechief flexor ofthe thigh

Extends andlaterally rotatesvertebral column


Additional ConceptAbdominal AortaThe abdominal aorta is the continuation of the thoracic aortaafter it passes through the aortic hiatus of the diaphragm.Theabdominal aorta terminates by dividing into common iliacarteries at L4 vertebral level.The abdominal aorta gives:

■ paired visceral branches: suprarenal, renal, and gonadal■ unpaired visceral branches: celiac trunk, superior mesen-

teric and inferior mesenteric arteries■ paired parietal: inferior phrenic and lumbar■ unpaired parietal: median sacral artery.

Venous DrainageVeins generally parallel arteries and drain into the inferiorvena cava, with the notable exception of the portal system,which drains to the liver.


Vessels of the abdominal wall (continued)

Artery Origin DescriptionSuperficial Femoral Supplies: region between umbilicusepigastric and pubis

Superficial circum- Supplies: inguinal region and flex iliac anterosuperior thigh

Deep circumflex External iliac Supplies: iliacus and anterolateraliliac abdominal wall

Subcostal Thoracic aorta Supplies: anterolateral abdominal wall

Lumbar Abdominal aorta Supplies: back and posterior (4–5 pairs) abdominal wall

Testicular Supplies: testes and epididymis

Artery of the Inferior vesical Supplies: ductus deferensductus deferens artery

Cremasteric Inferior epigastric Supplies: cremaster muscle andartery fascia

Vein Termination DescriptionPampiniform Plexus converges Drains the spermatic cord and testesplexus to form the

testicular veins

Nerves of the abdominal wall

Nerve Origin Structures InnervatedThoracoabdominals T7–T11 Anterolateral abdominal wall superior

Subcostal T12 to iliac crest

(continued)


MnemonicLumbar PlexusLumbar plexus nerve roots: 2 from 1, 2 from 2, 2 from 3:

2 nerves from 1 root: ilioinguinal (L1), iliohypogastric (L1).2 nerves from 2 roots: genitofemoral (L1–L2), lateral cuta-

neous nerve of the thigh (L2–L3). 2 nerves from 3roots: obturator (L2–L4), femoral (L2–L4).


Feature Description SignificanceWall Double layered: skin and • Outpouching of lower

superficial fascia (dartos): anterior abdominal wallcontains smooth muscle • Dartos muscle receives fibers—dartos muscle autonomic innervation and

functions to wrinkle the skin

Arterial SupplyPosterior scrotal Origin: perineal artery Supplies posterior aspectbranches

Anterior scrotal Origin: external pudendal Supplies anterior aspectbranches artery

Cremaster Origin: inferior epigastric Supplies the superior aspectartery artery

Structure of the scrotum

Nerves of the abdominal wall (continued)


Lumbar PlexusIliohypogastric L1 Anterolateral abdominal wall of

inguinal and hypogastric regions

Ilioinguinal Scrotum/labia majorum, mons pubis,medial thigh, and lower-most aspect of anterolateral abdominal wall

Genitofemoral L1, L2 Divides into genital and femoral branches;genital branch supplies cremaster and cutaneous innervation to anterior aspectof scrotum; femoral branch is sensoryto anteromedial aspect of thigh

Lateral cutaneous L2, L3 Supplies sensory innervation to nerve of the thigh anterolateral aspect of thigh

Obturator L2–L4 Supplies adductor compartment of thigh

Femoral Supplies hip flexors and knee extensors

Lumbosacral trunk L4, L5 Participates in formation of sacral plexus (L4–S4)

(continued)


The testes and epididymis are presented with the reproductiveorgans in the pelvis and perineum chapter.

Clinical SignificanceSensory Innervation of the ScrotumAs the anterior aspect of the scrotum is supplied bybranches of the ilioinguinal nerve and the posterior aspectby the branches of the perineal and posterior femoral cuta-neous nerves, care must be taken to properly anesthetize thescrotum for surgical procedures.

Structure of the spermatic cordThe spermatic cord runs through the inguinal canal into thescrotum.The cord contains structures coursing between thescrotum and the abdominopelvic cavity.


Feature Description SignificanceNerve Supply

Genital branch Origin: genitofemoral nerve Supplies anterolateral of genitofemoral (L1–L2) surfacenerve

Anterior scrotal Origin: ilioinguinal nerve Supplies anterior surfacenerves (L1)

Posterior scrotal Origin: perineal branches of Supplies posterior surfacenerves pudendal nerve (S1–S4)

Perineal Origin: posterior femoral Supplies inferior surfacebranches of cutaneous nerve (S2–S3)posterior femoralcutaneous

Structure of the scrotum (continued)


Fascial coverings • Internal—internal • Internal spermatic—of spermatic spermatic fascia derived from transversalis cord • Middle—cremaster fascia fascia

• External—external • Cremaster—derivedspermatic fascia from internal oblique

• External spermatic—derived from external oblique

(continued)


Clinical SignificanceTemperature RegulationThe cremaster muscle (skeletal muscle), found with thecremaster fascia, draws the testes toward the body in coldtemperatures as part of the cremasteric reflex. The dartosmuscle (smooth muscle) causes wrinkling of the scrotum todraw the testes nearer the body and reduce the surface areaof the scrotum in cold temperatures.

PERITONEAL CAVITY


Structure of the peritoneal cavity(Figure 2-1)

The peritoneal cavity is a potential, fluid-filled spacebetween adjacent layers of peritoneum in the abdomen. It isdivided into a lesser and a greater sac that correspond totheir embryologic origins as the right and left halves of theintraembryonic cavity.

Structure Description SignificanceComponentsDuctus deferens Tube composed of smooth Conveys sperm from the

muscle epididymis to the ejaculatory duct

Testicular artery Arises from abdominal aorta Supplies testes andepididymis

Artery of the Arises from inferior vesical Supplies ductus deferensductus deferens artery

Cremasteric Arises from inferior Supplies cremaster muscle artery epigastric artery and fascia

Pampiniform Venous plexus that drains the Converges to form the plexus of veins testes and spermatic cord testicular veins

Autonomics Sympathetic and • Innervates dartos and parasympathetic nerve vessels of regionnetwork • Responsible for peristaltic

contractions during emission

Genital branch Origin: L1–L2; divides into Supplies cremaster muscleof genitofemoral genital and femoral

branches

Structure of the spermatic cord (continued)



Bounded by:• Anterior—liver,

stomach and lesseromentum

• Posterior—diaphragm• Right—liver• Left—gastrosplenic

and gastrorenalligaments

Limited by diaphragm andposterior leaf of coronaryligament of the liver

Limited by fusion ofanterior and posteriorleafs of greater omentum

All of the peritonealcavity that is not thelesser sac

Located posterior to theportal triad and anteriorto the inferior vena cava

Depressions runningparallel with theascending anddescending colon alongthe posterior abdominalwall

Formed by the mesenteryof the transverse colon—the transverse mesocolon

Superior extensions of theperitoneal cavity betweenthe diaphragm and liver

Extension of peritonealcavity inferior to the liverand anterior to the kidneyand suprarenal gland

• Smaller portion of theperitoneal cavity

• Formed by embryologicrotation of the gut

Superior extent of thelesser sac

Inferior extent of thelesser sac

• Larger portion of theperitoneal cavity

• Formed by embryologicrotation of the gut

Connection between thelesser and greater sac

• Function as channelsthat convey peritonealfluid

• Communicationbetween supra- andinfracolic compartments

Part of the peritonealcavity superior to thetransverse mesocolon

Part of the peritonealcavity inferior to thetransverse mesocolon

Separated into right andleft by the falciformligament

• Communicatesanteriorly with the rightsubphrenic space

• Communicates withomental bursa (lessersac)—fluid may draininto recess from herewhen supine

Structure of the peritoneal cavity (continued)

Feature Description SignificanceLesser sac (omental bursa)

Superior recess of lesser sac

Inferior recess of lesser sac

Greater sac

Omental foramen

Paracolic gutters

Supracolic compartment

Infracolic compartment

Subphrenic spaces

Hepatorenal recess

(continued)



Feature Description SignificancePeritoneal FossaeSupravesical fossae

Medial inguinal fossae (related to inguinal triangles)

Lateral inguinal fossae

Between the median andmedial umbilical folds

Between the medial andlateral umbilical folds

Lateral to the lateralumbilical folds

Potential site for a hernia

Potential site for a directinguinal hernia

Deep inguinal rings foundwithin fossae, potentialsite for indirectinguinal hernia

Peritoneal pouches are presented with the pelvis.

Clinical SignificancePeritoneal PunctureOccasionally it is necessary to puncture the peritoneum toremove excess fluid (ascites) that accumulates duringinflammation, to conduct peritoneal dialysis or administeranesthetic agents through intraperitoneal injection.

Peritoneum (Figure 2-1)

Structure Description SignificanceParietal peritoneum

Visceral peritoneum

Mesentery

Peritoneal FoldsMedian umbilical fold

Medial umbilical folds (2)

Serous membrane liningthe peritoneal cavity

• Double layer ofperitoneum connectingintraperitoneal organs tothe abdominal wall

• Conveys neurovascularelements and lymphatics

• Allows movement of theorgan to which it isattached

Fold of parietal peritoneumextending from the apex ofthe bladder to the umbilicus

Fold of parietal peritoneumfound lateral to the medianumbilical fold

Lines internal surface ofabdominal wall

Lines external surfaces ofabdominal organs

• The “mesentery” refersspecifically to the mes-entery of the small intestine

• Other mesenteries arenamed specifically for theorgans to which they areassociated (e.g., transversemesocolon ormesoappendix)

Covers the medianumbilical ligament—theremnant of the urachus

Covers the medial umbilicalligaments—the obliteratedpart of the umbilical arteries

(continued)



Peritoneum (continued)

Fold of parietal peritoneumfound lateral to the medialumbilical folds

Double layer of peritoneumconnecting greater curvatureof stomach and proximalduodenum to adjacent organs

• Double layer ofperitoneum connectinglesser curvature of thestomach and proximalduodenum to adjacentorgans

• Forms anterior wall oflesser sac

• Double layer ofperitoneum extendingfrom umbilicus to liver onanterior abdominal wall

• Continuous superiorly asleft and right coronaryligament

• Anterior formed byseparation of leafs offalciform ligament

• Posterior is formed ofperitoneal reflexion fromdiaphragm to liver

Formed of anterior andposterior coronaryligaments

Connective tissue cord ininferior border of falciformligament

Covers the inferiorepigastric vessels

3 parts: 1. Gastrophrenic

ligament—connectsstomach to diaphragm

2. Gastrosplenicligament—connectsstomach to spleen

3. Gastrocolic ligament—connects stomach totransverse colon, largestpart, anterior and posteriorlayers are fused to form a4-layered structure

2 parts:1. Hepatogastric

ligament—connectsstomach to liver

2. Hepatoduodenalligament—connectsduodenum to liver, containsportal triad: portal vein,hepatic artery and bile duct

• Embryologic remnant ofthe ventral mesentery

• Contains round ligament ofthe liver in its inferior,crescentic border

Bound the bare area of theliver

Formed of a peritonealreflexion between anteriorand posterior leafs ofcoronary ligaments

Embryologic remnant of theumbilical vein

Structure Description SignificanceLateral umbilical folds (2)

OmentaGreater

Lesser

Associated with the LiverFalciform ligament

Coronary ligaments (anterior and posterior)

Triangular ligaments (right and left)

Round ligament of liver


Liver

Lesser omentum

Pancreas

Falciformligament

Stomach

Duodenum

Transversemesocolon

Transverse colon

Mesentery ofsmall intestine

Greater omentum

Jejunum

Ileum

Visceral peritoneum

Parietal peritoneum

Rectovesical pouch

Urinary bladder

Rectum

Superior recess of omental bursa

Inferior recess of omental bursa

Transversemesocolon

Left colicflexure

A Right lateral view

B Anterior view

Transversecolon

Right colicflexure

Supracoliccompartment

Ascendingcolon

Tenia coli

Descendingcolon

Root ofmesentery ofsmall intestine

Leftparacolicgutter

Leftinfracolicspace

Rightparacolicgutter

Rightinfracolicspace

Phrenicocolicligament

Infracolic compartment

Subhepaticspace

Supracoliccompartment(greater sac)

Omentalbursa(lesser sac)Infracoliccompartment(greater sac)

FIGURE 2-1. Subdivisions of peritoneal cavity. A: This median

section of the abdominopelvic cavity shows the subdivisions of the

peritoneal cavity. B: The supracolic and infracolic compartments of

the greater sac are shown after removal of the greater omentum.The

infracolic spaces and paracolic gutters determine the flow of ascitic

fluid when inclined or upright. (From Moore KL, Dalley AF.

Clinically Oriented Anatomy. 5th ed. Baltimore: Lippincott Williams

& Wilkins; 2006:239.)

46


Additional ConceptsPeritoneal RelationsOrgans that are suspended by a mesentery are said to beintraperitoneal. Organs that lack a mesentery and are onlypartially covered with peritoneum are said to be extraperi-toneal (retroperitoneal or subperitoneal provides more indi-cation of their location).

Median Umbilical LigamentThe median umbilical ligament is formed by the urachus,the obliterated portion of the allantois, connecting the apexof the bladder with the umbilicus.

Medial Umbilical LigamentsThe medial umbilical ligaments are formed by the oblit-erated portions of the umbilical arteries distal to the supe-rior vesical arteries.

Clinical SignificanceHerniaeA direct inguinal hernia (acquired) exits the abdomen viathe medial inguinal fossa or inguinal triangle, which isbounded medially by the semilunar line (lateral border ofrectus abdominis), laterally by the lateral umbilical folds andinferiorly by the inguinal ligament.

An indirect inguinal hernia (congenital) exits theabdomen via the deep inguinal ring and passes through theinguinal canal into the scrotum.

AdhesionsAdhesions may develop in the peritoneal cavity as a result ofinflammation of the peritoneum (peritonitis) or previoussurgery, which may need to be removed if they compromisethe function of the viscera.

MnemonicStructures forming folds: IOU:From lateral to medial:

lateral umbilical ligament: Inferior epigastric vesselsmedial umbilical ligament: Obliterated umbilical arterymedian umbilical ligament: Urachus



ESOPHAGUS


Feature Description SignificanceSphincters

Innervation

Arterial supply

Venous drainage

Structure of the esophagusThe esophagus is a muscular tube extending from the cricoidcartilage to the gastroesophageal junction; it enters theabdomen through the esophageal hiatus of the diaphragm.The nature of the musculature of the esophagus changesthroughout its course:

■ upper third—skeletal muscle■ middle third—mixture of smooth and skeletal muscle■ lower third—smooth muscle

2 sphincters:

1. Upper esophagealsphincter—skeletalmuscle

2. Lower esophagealsphincter—smoothmuscle and skeletalmuscle of diaphragm

• Skeletal muscle part—recurrent branches ofthe vagus nerve

• Smooth muscle part—esophageal plexus

Inferior thyroid,esophageal, bronchial,left gastric and leftinferior phrenic arteries

Esophageal veins emptyinto the inferior thyroid,azygos, hemiazygos andgastric veins

• Upper sphinctercomposed mainly ofcricopharyngeus

• Lower sphincter—smooth muscle andmuscular diaphragmaticesophageal hiatusprevent gastroe-sophageal reflux

Esophageal plexus—parasympathetic fibersfrom the vagus nerves andsympathetic fibers fromsympathetic chain andgreater splanchnic nerve

Arterial supply is generallyvia whatever arteries lienear this long longitudi-nally oriented structure

Important contributor tothe portal-cavalanastomosis

Clinical SignificanceEsophageal VaricesEsophageal varices are dilated esophageal veins that mayrupture in cases of portal hypertension.

PyrosisPyrosis (heartburn) is usually the result of regurgitation ofstomach contents into the lower esophagus.


STOMACH


Structure of the stomach(Figure 2-3)

The stomach is the muscular organ of digestion; it produceschyme through enzymatic digestion.

Part surrounding cardialorifice

Part superior to cardialorifice

Part between fundus andpyloric antrum

• Distal-most part of thestomach

• Possesses smoothmuscle sphincter—pyloric sphincter,which guards thepyloric orifice thatopens into theduodenum

• Funnel-shaped• Divided into the

pyloric antrum (wide)and pyloric canal(narrow)

Directed inferior and tothe left

Directed superior and tothe right

Longitudinal folds ofgastric mucosa

Cardial orifice—funnel-shaped opening ofstomach that receives theesophagus

Typically dilated and gas-filled

Major part of thestomach

Pyloric sphincter controlsrelease of gastriccontents into theduodenum and preventsreflux from duodenuminto stomach

Longer, convex curvature

• Shorter, concavecurvature

• Bears the angularincisure—outerrepresentation of thejunction of the bodyand pyloric part

Function to increasesurface area and allowfor distension

Feature Description SignificancePartsCardia

Fundus

Body

Pylorus

CurvaturesGreater

Lesser

InteriorRugae (gastric folds)


Clinical SignificancePylorospasmPylorospasm is the failure of the pyloric sphincter torelax, which prevents food from passing from the stomachto the duodenum, often occurs in infants and may resultin vomiting.


Vessels of the stomach (Figure 2-4)

• Supplies embryologicforegut

• Gives rise to: splenic,hepatic and left gastricarteries

• Supplies the spleen• Gives rise to left gastro-

omental and short gastricarteries to the stomach

• Supplies the liver• Gives rise to gastroduodenal

and right gastric arteries tothe stomach

• Supplies the stomach,duodenum and liver

• Gives rise to right gastro-omental to the stomach

Supplies lesser curvature ofthe stomach

Supplies greater curvature ofthe stomach

Supply body of stomach

Description

Drain lesser curvature ofstomach

Drain greater curvature ofstomach

Drain body of stomach

Artery Origin DescriptionCeliac trunk

Splenic

Hepatic

Gastroduodenal

Right gastric

Left gastric

Right gastro-omental

Left gastro-omental

Short gastric

VeinLeft gastric

Right gastric

Left gastro-omental

Right gastro-omental

Short

Abdominal aorta

Celiac trunk

Hepatic

Celiac trunk

Gastroduodenal

Splenic

TerminationPortal

Splenic

Superior mesenteric

Splenic



Nerves of the stomach

Nerve Origin Structures InnervatedParasympathetic Vagus nerves Anterior and posterior vagal

trunks enter abdomenthrough the esophagealhiatus

Sympathetic Presynaptics originate • Presynaptic sympathetics from the intermedio- are conveyed to the celiac lateral cell column of the plexus/gangliaspinal cord and travel • Postsynaptic fibers travel in the sympathetic on branches of the celiac trunks and splanchnic trunk to the stomachnerves to reach • Reduces motility, activates abdominal plexuses sphincters, vasoconstricts

and decreases glandular activity

Visceral afferent Cell bodies located in Stomach sensitive to spinal ganglia stretching and distension

SMALL INTESTINE

Structure of the small intestine(Figures 2-3 and 2-5)

The small intestine extends from the pylorus to the cecum.It is the primary site of digestion and absorption in the body.The small intestine is divided into three parts:

1. duodenum2. jejunum3. ileum

• 1st part of smallintestine

• Divided into 4 parts:1. Superior2. Descending3. Horizontal4. Ascending

• Superior part isintraperitoneal, theremaining parts areretroperitoneal

• Descending partreceives the bile andmain pancreatic ductsvia hepatopancreaticampulla

• Ascending partcontinuous withjejunum atduodenojejunaljunction

• 1st part referred to asduodenal cap/bulb

Structure Description SignificanceDuodenum

(continued)



Junction of duodenumand jejunum, evidencedby the duodenojejunalflexure

• 2nd part of the smallintestine

• Intraperitoneal,connected to theposterior abdominalwall by the mesentery

• 3rd part of the smallintestine

• Intraperitoneal,connected to theposterior abdominalwall by the mesentery

Junction of the ileum and the cecum

The sharp angle of theduodenojejunal flexure issupported by thesuspensory muscle of theduodenum (ligament ofTreitz)—a slip offibromuscular tissue thatsupports the flexure

Constitutes �2/5 of thesmall intestine distal tothe duodenum

Constitutes the distal partof the small intestine,extending from thejejunum to the ileocecaljunction

Invagination of the ileuminto the cecum forms foldssuperior and inferior to theileal orifice, forming theileocecal valve

Structure Description SignificanceDuodenojejunaljunction

Jejunum

Ileum

Ileocecal junction

Additional ConceptDistinguishing Characteristics between the Jejunum and Ileum The jejunum has greater vascularity, longer vasa recta, fewerand larger arterial arcades, less fat in the mesentery, moreprominent plicae circulares, and fewer lymphatic elementsthan the ileum.

Vessels of the small intestine(Figure 2-3)

The celiac trunk and gastroduodenal arteries are presented

with the vessels of the stomach.

Structure of the small intestine (continued)

Artery Origin DescriptionSuperior Gastroduodenal Supplies proximal part ofpancreaticoduodenal duodenum

(continued)



Artery Origin DescriptionSuperior mesenteric Abdominal aorta • Supplies alimentary canal

to left colic flexure• Supplies embryologic

midgut

Inferior Superior mesenteric Supplies distal part ofpancreaticoduodenal duodenum

Arterial arcades Gives rise to vasa recta thatsupply the jejunum and ileum

Additional ConceptVenous DrainageVenous drainage parallels arterial supply and terminates inthe portal vein.

Embryologic Arterial SupplyThe descending part of the duodenum marks the transitionbetween the embryologic foregut and midgut, the location ismarked by anastomosis of branches of the celiac trunk(artery of the foregut) with branches of the superior mesen-teric artery (artery of the midgut).

Nerves of the small intestine

Nerve Origin Structures InnervatedParasympathetic Vagal—primarily • Presynaptic parasympathetic

the posterior vagal fibers synapse in thetrunk myenteric and submucosal

plexuses in the wall of the small intestine

• Increases motility andglandular secretion and inhibits sphincters

Sympathetic Presynaptics • Presynaptic sympatheticsoriginate from the are conveyed to the celiacintermediolateral cell and superior mesentericcolumn of the spinal plexuses/gangliacord and travel in the • Postsynaptic fibers travelsympathetic trunks and on branches of the superiorsplanchnic nerves to mesenteric artery to the reach abdominal small intestineplexuses • Reduces motility, activates

sphincters, vasoconstricts anddecreases glandular activity

(continued)

Vessels of the small intestine (continued)


LARGE INTESTINE

Structure of the large intestine(Figure 2-2)

The large intestine extends from the ileocecal junction tothe anus. It is divided into four parts:

1. cecum2. colon3. rectum4. anal canal

The large intestine is the part of the digestive tract distal tothe small intestine; it is primarily responsible for water andelectrolyte resorption.


Nerves of the small intestine (continued)

Nerve Origin Structures InnervatedVisceral afferent Cell bodies located in Small intestine sensitive

spinal ganglia to stretching, distension, and pain

Structure Description SignificancePartsCecum • 1st part of large intestine Mostly covered by visceral

• Continuous with ascending peritoneum, although has no colon mesentery

• Ileum joins it at ileocecal junction

Appendix • Diverticulum extending Variable location, but usually from cecum is posterior to the cecum

• Possesses a mesentery—mesoappendix

Colon • 2nd part of large intestine • The ascending and • Divided into 4 parts: descending colon are retro-

1. Ascending colon peritoneal, although they extends from cecum to are only loosely fixed to right colic flexure the posterior abdominal

2. Transverse colon wall by a loose connectiveextends from right colic tissue fascia—fusion fas-flexure to left colic cia and, therefore, easily flexure mobilized during surgery

3.Descending colon • On the lateral aspects, extends from left colic are the paracolic guttersflexure to sigmoid colon • The transverse and sigmoid

4. Sigmoid colon colon each have follows an S-shaped mesenteries— the trans-course to the rectum verse and sigmoid

mesocolons

(continued)



Structure of the large intestine (continued)


Rectum • 3rd part of large intestine • Dilated terminal portion—• Extends from the sigmoid the ampulla, retains feces

colon at S3 to the anal until defecationcanal • The proximal third of the

• Possesses 3 lateral flexures rectum is covered bythat correspond to 3 trans- peritoneum on the anteriorverse rectal folds, which and lateral aspect, thecorrespond to thickenings middle third only has of the muscular wall peritoneum on the anterior

surface, whereas the inferior 3rd is subperitoneal

Anal canal • 4th part of large intestine • The anorectal flexure is • Begins at the anorectal the primary structure that

flexure at the level of the maintains fecal continence,pelvic diaphragm and it is a sharp bend maintainedextends to the anus by tonic contraction of

• Internally possesses anal puborectalis; its relaxation columns—longitudinal is necessary if defecation ridges joined at their base is to occurby anal valves, anal glands • Feces compressing theopen into the anal sinuses anal sinuses causes (recesses formed by anal exudation of mucus thatvalves) lubricates the anal canal

Features

Teniae coli 3 longitudinally oriented The longitudinal layer of bands of smooth muscle of smooth muscle surrounding the large intestine the digestive tract is reduced

to 3 bands over the large intestine

Haustra Sacculations of the large Slow the passage of feces intestine through the large intestine

Omental Small, fatty projections Allow for reduced friction appendices hanging from the wall of with nearby structures during

the large intestine movement of the large intestine as feces passes through

Additional Concept Differences between the Small and Large IntestineThe large intestine has a larger diameter than the small intestine and possesses teniae coli, haustra and omental appendices, all of which are unique to the largeintestine.


Clinical SignificanceMcBurney’s PointUsual location of proximal (open end) of the appendix,located one third of the way along an oblique line connect-ing the anterior superior iliac spine to the umbilicus.

Sphincters of Anal CanalThe anal canal is surrounded by two sphincters, both ofwhich are involved in the maintenance of fecal continence, theinternal (involuntary) and external (voluntary, divided intodeep, superficial, and subcutaneous parts) anal sphincters.

Pectinate LineThe inferior border of the anal valves forms the pectinateline. Above the pectinate line, the anal canal is derived fromthe embryologic hindgut (visceral—autonomic innervation,inferior mesenteric arterial supply, venous drainage to por-tal system, and lymphatics to internal iliac nodes), below theline it is derived from the proctodeum (somatic—somatic


Sigmoid colon

Rectum

Ampulla of rectum

FIGURE 2-2. Anteroposterior barium radiograph showing parts

of the large intestine; note the haustra and flexures of the colon.

(From Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd ed.

Baltimore: Lippincott Williams & Wilkins; 2008:138.)


innervation, internal iliac arterial supply, venous drainage tocaval system, and lymphatics to inguinal nodes).

Teniae ColiProximally, the teniae coli converge at the base of theappendix and thereby aid in location of the appendix duringsurgery.


Vessels of the large intestine


Superior Abdominal • Supplies alimentary canal to left colic mesenteric aorta flexure

• Supplies embryologic midgut

Ileocolic Superior • Supplies cecummesenteric • Gives rise to appendicular artery

Appendicular Ileocolic Supplies appendix

Right colic Superior Supplies ascending colon

Middle colicmesenteric

Supplies transverse colon

Inferior mesenteric Abdominal • Supplies alimentary canal to the anal aorta canal

• Supplies embryologic hindgut

Left colic Inferior Supplies descending colon

Sigmoidmesenteric

Supplies sigmoid colon

Marginal Ileocolic, right Anastomotic loop forming collateral colic, middle circulation along the large intestine colic, left colic, and sigmoids

Superior rectal Inferior Superior aspect of rectummesenteric

Middle rectal Inferior vesical Mid and inferior aspect of rectum(male) or uterine(female)

Inferior rectal Internal Anal canalpudendal

Additional ConceptVenous DrainageVenous drainage parallels arterial supply and terminates inthe portal vein until the level of the junction of the superiorand middle aspects of the rectum; inferior to this point,venous drainage is to the caval system.


Structure of the liver(Figures 2-3 and 2-5)

The liver is the largest internal organ and the largest glandin the body. It is surrounded by a connective tissue cap-sule—Glisson’s capsule. The liver is divided into anatomiclobes:

■ right■ left■ caudate■ quadrate

Functional units of the liver are called hepatic lobules—plates of hepatocytes surrounded by sinusoids, which areorganized around portal triads. The liver receives all sub-stances absorbed by the digestive tract (except lipids), storesglycogen, and secretes bile.


Nerves of the large intestine

Nerve Origin Structures InnervatedLarge Intestine Proximal to Pectinate Line of Anal CanalParasympathetic • Vagal—to the • Presynaptic parasympathetic fibers

mid-transverse synapse in the in the wall of the colon large intestine

• S2–S4 via • Increases motility and glandularpelvic splanch- secretion and inhibits sphinctersnic nerves

Sympathetic Presynaptics • Postsynaptic fibers travel on originate from branches of superior and inferior the intermediola- mesenteric arteries to the large teral cell column intestineof the spinal cord • Reduces motility, activates sphincters,and travel in the vasoconstricts and decreasessympathetic glandular activitytrunks and splanchnic nervesto reach abdominal plexuses

Visceral afferent Cell bodies • Large intestine sensitive to pain, located in spinal stretching and distensionganglia • Afferents involved in reflexes travel

with the vagus nerve

Large Intestine Distal to Pectinate Line of Anal CanalInferior rectal Pudendal • Somatic innervation

• Anal canal inferior to pectinate line



Structure Description SignificanceAnatomic LobesRight Located to the right of the Demarcated by the left and

right sagittal fissure right sagittal fissures and theporta hepatis

Left Located to the left of the left sagittal fissure

Caudate Between the left and right sagittal fissures, posterior to the porta hepatis

Quadrate Between the left and right sagittal fissures, anterior to the porta hepatis

FeaturesPorta hepatis Fissure on inferior aspect of • Structures passing through

liver where structures enter the porta hepatis include: and leave that are enclosed 1. Common bile ductin the hepatoduodenal 2. Portal veinligament 3. Hepatic artery

4. Lymphatics• The first 3 structures

compose the portal triadBare area • Area on posterior aspect Provides potential route of

of liver that lacks infection between the peritoneum abdominal and thoracic

• Bounded by the coronary cavitiesligaments

Left sagittal • Fissure on inferior aspect Contains: fissure of liver • Ligamentum venosum—

• Separates the left lobe remnant of ductus from the quadrate and venosus, an embryologic caudate lobes shunt for blood

• Round ligament—remnant of umbilical vein

Right sagittal • Fissure on inferior aspect Contains: fissure of liver • Inferior vena cava in

• Separates quadrate and the groove for thecaudate lobes from right inferior vena cavalobe of liver • Gall bladder in the fossa

of the gall bladder

Right and left Drain bile from the right and • Right and left bile ducts joinhepatic ducts left lobes inferior to the liver to form

the common hepatic duct• Release of bile into the

hepatopancreatic ampulla is controlled by the sphincter of the bile duct

Structure of the liver (continued)


The remainder of the biliary tree is presented with the gall blad-der and pancreas.

Additional Concept Functional Divisions of the LiverThe liver can also be divided functionally into right and leftfunctional lobes, based on the branching pattern of the rightand left hepatic arteries.

Clinical SignificanceCirrhosisCirrhosis of the liver is characterized by the replacement ofhealthy liver cells with fat and fibrous tissue; it is most com-monly seen in alcoholics and is a common cause of portalhypertension.


Right branchesof hepatic duct, hepaticartery,and portal vein

Round ligament

Falciform ligamentLeft branches of commonhepatic duct, portal vein, andhepatic artery

Common hepaticartery

Spleen

Stomach

Splenicartery

Inferiormesentericvein

Superior mesenteric artery

Portal vein

Pylorus

DuodenumHead of pancreas

Cysticartery

Superior mesenteric vein

Splenicvein

Gallbladder

FIGURE 2-3. Liver. Anterior view. (Asset provided by Anatomical

Chart Company.)


Clinical SignificancePortal HypertensionPortal hypertension is indicated by a rise in pressure in theportal vein and is often caused by cirrhosis, characterized byscarring and fibrosis of the liver. This causes blood to flowinto the systemic (caval) system at sites of portal-systemicanastomosis, producing varicose veins.


Vessels of the liver(Figures 2-3 and 2-4)

Artery Origin DescriptionCeliac trunk Abdominal • Gives rise to splenic, hepatic, and

aorta left gastric arteries• Supplies embryologic foregut

Hepatic Celiac trunk • Supplies the liver• Gives rise to right and left hepatic

arteries

Right and left Hepatic Supply right and left lobes of liverhepatic

Vein Termination DescriptionRight, middle and Inferior vena • Drain into inferior vena cava left hepatic cava immediately inferior to the diaphragm

• Help to hold liver in place

Portal Sinusoids of • Formed by the junction of the splenic liver and superior mesenteric veins, which

typically receive the inferior mesentericvein

• Conveys all venous blood and absorbednutrients from the digestive tract from the inferior aspect of the esophagus to the anal canal

Nerves of the liver

Nerve Origin Structures InnervatedParasympathetic Vagus nerves Anterior and posterior vagal trunks

enter abdomen through the esophageal hiatus

Sympathetic Presynaptics originate • Presynaptic sympathetics are in the intermedio- conveyed to the celiac and lateral cell column of hepatic plexusthe spinal cord and tra- • Postsynaptic fibers travel on vel in the sympathetic branches of the hepatic arterytrunks and splanchnic to the livernerves to reach abdominal plexuses

LIVER



A Anterior view

EsophagusLiver

Rightinferiorphrenic

artery

Superiormesenteric

artery(to midgut)

Duodenum

Smallintestine

Ascendingcolon

Celiac trunk (artery;to foregut)

Left gastric artery

Spleen

Stomach

Inferiormesentericartery (tohindgut)

Descendingcolon

Aorta

Left inferior phrenic artery

Esophageal branch

Posteriorgastricartery

Splenicartery

B Anterior view

Right lobeof liver

Cystic vein

Gallbladder

Portal vein

Right gastricvein

Duodenum

Middle colicvein

Ileocolicvein

Appendicularvein

Right colicvein

Pancreatico-duodenal

veins

Short gastric vein

Spleen

InferiormesentericveinSuperiormesentericveinLeft colicveinsJejunal andileal veins

Splenic veinLeft and rightgastro-omentalveins

Pancreas

Cardial notch

To azygos venoussystem

Left gastric vein

Sigmoidveins

Superior rectalveins


GALL BLADDER

Structure of the gall bladder(Figures 2-3 and 2-5)

The gall bladder is a pear-shaped organ located in the ante-rior aspect of the right sagittal fissure of the liver in the gallbladder fossa. It stores and concentrates bile.


FIGURE 2-4. Arterial supply and venous drainage of GI tract. A:The arterial supple is demonstrated. B: The venous drainage is

shown. The portal vein drains poorly oxygenated, nutrient-rich

blood from the gastrointestinal tract, spleen, pancreas, and gall-

bladder to the liver.The black arrow indicates the communication of

the esophageal vein with the azygos (systemic) venous system.

(From Moore KL, Dalley AF. Clinically Oriented Anatomy. 5th ed.


Additional Concept Extrahepatic Duct SystemThe cystic duct of the gall bladder joins the commonhepatic duct—formed by the junction of the right and lefthepatic ducts—to form the common bile duct. The cysticduct drains bile from the gall bladder and the mucosa of thecystic duct is folded in a spiral fashion to form the spiralvalve, which functions to keep the duct open. The hepaticducts function to drain bile from the liver.The common bileduct ends at the hepatopancreatic ampulla, where it joinsthe main pancreatic duct; release of contents into the duodenum is controlled by the sphincter of the hepatopan-creatic ampulla—sympathetic innervation causes thesphincter to contract. The remainder of the biliary tree ispresented with the liver and pancreas.

Structure Description SignificanceFundus Expanded anterior-most end Located near the 9th costal

cartilage in the midclavicularline

Body Located between the fundus In contact with inferior and neck surface of liver

Neck Narrow posterior-most part; Makes S-shaped bend to directed toward porta hepatis join cystic duct


Clinical SignificanceGall StonesConcretions (gall stones) from the gall bladder may lodgein the hepatopancreatic ampulla, causing bile to backupinto the pancreas, leading to pancreatitis, jaundice, andpain. The gall bladder is often removed via laparoscopiccholecystectomy.


Duodenum

Right hepatic duct

Left hepatic duct

Common hepatic duct

Gallbladder

Cystic duct

Common bile duct

FIGURE 2-5. Endoscopic retrograde cholangiograph shows the

normal gallbladder and biliary tree. Note that the cystic duct nor-

mally lies on the right side of the common hepatic duct and joins it

superior to the duodenal cap. (From Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott Williams &

Wilkins; 2008:125.)


Additional ConceptVenous DrainageVenous drainage from the biliary tree and neck of the gallbladder is via the cystic veins—they either drain directly intothe liver or into the portal vein. Venous drainage from theremainder of the gall bladder is directly into the liver.


Vessels of the gall bladder(Figures 2-3 and 2-4)


Celiac trunk Abdominal Gives rise to splenic, hepatic, and left aorta gastric arteries; supplies embryologic

foregut

Hepatic Celiac trunk Gives rise to right and left hepatic arteries

Right and left Hepatic Gives rise to cystichepatic arteries

Cystic Right hepatic Supplies gall bladder and cystic duct

Nerves of the gall bladder


Parasympathetic Vagal Presynaptic parasympathetic fibers synapse on nerve cell bodies in the wall of the gall bladder

Sympathetic Presynaptics Postsynaptic fibers travel on branches originate in the of arteries to reach the gall bladderintermediolateralcell column of the spinal cord and travel in the sym-pathetic trunks and splanchnic nerves to reach abdominal plexuses

Visceral afferent Cell bodies Gall bladder sensitive to pain

Right phreniclocated in spinal

• Somatic afferent innervation,gangliaprimarily mediating pain

• Conveyed to cervical spinal cord


PANCREASStructure of the pancreas(Figures 2-3 and 2-5)

The pancreas is an elongated, lobulated, retroperitonealorgan found along the posterior abdominal wall. It has bothan exocrine and endocrine function:

■ exocrine—produces pancreatic digestive enzymes■ endocrine—produces glucagon and insulin


Structure Description SignificancePartsHead Expanded part Lies in concavity of the

C-shaped duodenum

Uncinate Hook-shaped projection • Posterior relations: inferior process from head vena cava, right renal

vessels and left renal vein• Anterior relations: superior

mesenteric artery

Neck Short part between head Overlies junction of superior and body mesenteric and splenic veins

to form the portal vein

Body Part between neck and tail Lies to the left of the superior mesenteric vessels

Tail • Mobile Related to hilum of spleen • Located in splenorenal and left colic flexure

ligament

FeaturesMain pancreatic • Begins at tail and extends • Merges with bile duct in duct to head head of pancreas to form

• Conveys pancreatic hepatopancreatic enzymes ampulla, which opens into

• Release of pancreatic descending part of enzymes regulated by duodenum at the majorsmooth muscle sphincter— duodenal papillasphincter of pancreatic • Release of contents intoduct the duodenum is controlled

by a smooth muscle sphincter—hepatopan-creatic sphincter (sphincter of Oddi) that surrounds the ampulla

Accessory • Drains uncinate process Empties into descending part pancreatic duct and part of head of of duodenum at minor

pancreas duodenal papilla• Conveys pancreatic enzymes


The remainder of the biliary tree is presented with the gallbladder and liver.

Clinical SignificancePancreatic CancerPancreatic cancer results in a low survival rate as a result ofdifficulty to identify and treat because of its location andeasy route of metastasis to the liver.


Vessels of the pancreas(Figures 2-3 and 2-4)

Artery Origin DescriptionCeliac trunk Abdominal • Gives rise to splenic, hepatic, and left

aorta gastric arteries• Supplies embryologic foregut

Splenic Celiac trunk Gives rise to dorsal, caudal, and great pancreatic arteries

Dorsal pancreatic Splenic Supplies body and tail

Great pancreatic

Caudal pancreatic

Hepatic Celiac Gives rise to gastroduodenal

Gastroduodenal Hepatic Gives rise to anterior and posterior superior pancreaticoduodenals

Anterior and Gastroduodenal Supply head and neckposterior superior pancreaticoduo-denals

Superior Abdominal • Gives rise to anterior and posterior mesenteric aorta inferior pancreaticoduodenals

• Supplies alimentary canal to left colic flexure

• Supplies embryologic midgut

Anterior and Superior Supply head and neckposterior inferior mesentericpancreaticoduo-denals

Additional ConceptVenous DrainageVenous drainage is via the splenic and superior mesentericveins, which join to form the portal vein.


SPLEEN

Structure of the spleen(Figure 2-3)

The spleen is a lymphatic organ located in the upper leftquadrant of the abdomen. It functions to remove old orabnormal red blood cells, stores platelets, and producesantibodies.


Nerves of the pancreas

Nerve Origin Structures InnervatedParasympathetic Vagus nerves • Anterior and posterior vagal trunks

enter abdomen through the esopha-geal hiatus

• Secretomotor, although most pan-creatic secretion is controlled hormonally

Sympathetic Presynaptics • Presynaptic sympathetics are originate from conveyed to the celiac and superior the intermedio- mesenteric plexuseslateral cell • Postsynaptic fibers travel on branchescolumn of the of celiac and superior mesenteric spinal cord and arteries to pancreastravel in the sym- • Most pancreatic secretion ispathetic trunks controlled hormonallysplanchnic nerves to reach abdomi-nal plexuses

Structure Description SignificanceHilum Medially directed concavity • Site of entry and exit to

and from the spleen• Tail of the pancreas

contacts spleen here

Gastrosplenic Connects hilum of spleen to • Part of greater omentumligament greater curvature of stomach • Contains short gastric and

left gastroepiploic vessels

Splenorenal Connects hilum of spleen • Double layer of peritoneumligament to left kidney • Contains splenic vessels

Clinical Significance SplenomegalyThe spleen may enlarge (splenomegaly) from a variety ofreasons or may be damaged by broken ribs, causing profusebleeding.


Additional ConceptVenous DrainageVenous drainage is via the splenic vein, which joins the supe-rior mesenteric vein to form the portal vein.

KIDNEYS

Structure of the kidneys(Figures 2-6 and 2-7)

The kidneys and ureters are retroperitoneal organs locatedalong the posterior abdominal wall. The kidneys function toremove excess water, salts, and wastes from the blood. Theureters convey urine from the kidney to the urinary bladder.


Vessels of the spleen(Figures 2-3 and 2-4)

Artery Origin DescriptionCeliac trunk Abdominal • Gives rise to splenic, hepatic, and left

aorta gastric arteries• Supplies embryologic foregut

Splenic Celiac trunk • Easily identified by tortuous course• Travels in splenorenal ligament• Supplies spleen via 5 terminal branches

Nerves of the spleen

Nerve Origin Structures InnervatedParasympathetic Vagus nerves Anterior and posterior vagal trunks

enter abdomen through the esophageal hiatus

Sympathetic Presynaptics • Presynaptic sympathetics are originate from conveyed to the celiac plexus/gangliathe intermedio- • Postsynaptic fibers travel on brancheslateral cell of the splenic artery to the spleencolumn of the spinal cord and travel in the sympathetic trunks and splanchnic nerves to reach abdominalplexuses


Structure Description SignificanceParts Renal capsule Thin connective tissue • Outer surface of kidney

capsule that surrounds • Surrounded by perirenal kidney fat

Renal cortex • Between renal capsule Consists of cortical labyrinth and renal medulla and cortical rays

• Extends into renal medulla as renal columns

Renal medulla Between renal cortex and Contains renal pyramids and renal hilum renal columns

Renal hilum Concave medial-margin of Bounds renal sinuskidney

Renal pyramid • 5–10; conical-shaped • Compose major part of • Base adjacent to cortex, medulla

apex forms renal papilla • Renal columns intervene between adjacent pyramids

Renal papilla • 5–10 Open into minor calyces• Tip of renal pyramid

Renal sinus Area bounded by renal hilum • Space in concave medial-margin of kidney

• Contains renal vein, renal artery, and renal pelvis fromanterior to posterior

Minor calyces Located in renal sinus; Several minor calyces

Major calyces convey urine merge to form major calyces

• Formed by merging of several minor calyces

• Several major calyces merge to form renal pelvis

Renal pelvis • Located in renal sinus Narrows to form ureter—• Proximal expanded end of • Retroperitoneal

ureter • Conveys urine from kidney • Formed by merging of to urinary bladder

major calyces

FeaturesPerirenal fat Layer of protective fat Continuous with fat in renal

surrounding kidney and sinussuprarenal glands

Renal fascia Membranous layer between • Surrounds kidney, suprare-peri- and pararenal fat nal gland, and perirenal fat

• Continuous with fascia on inferior aspect of dia-phragm

Pararenal fat Fat external to renal fascia Thick, protective layer of fat

Structure of the kidneys (continued)

70


Renal pelvis

Hilum

Ureter

Medulla

Cortex

Renalpyramids

Renal capsule

Renal papilla

Renal lobe

Major calyx

Minor calyx

Renal column

Leftkidney

Minorcalyx

Majorcalyx

Renalpyramids

Renalpelvis

Ureter

FIGURE 2-6. Longitudinal section of the kidney, near the hilum.

(From Stedman’s Medical Dictionary. 27th ed. Baltimore: Lippincott

Williams & Wilkins; 2000.)

FIGURE 2-7. Intravenous urogram showing left kidney and prox-

imal ureter; note the calyces and renal pelvis. (From Dudek RW,

Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott

Williams & Wilkins; 2008:164.)

71


Clinical SignificanceConstrictions of the UretersUreters are constricted at three places: (1) at the junctionwith the renal pelvis; (2) where they cross the pelvic brim; and (3) as they pass through the wall of the urinarybladder.

Kidney TransplantationKidney transplantation is a well-established procedure toreplace failing kidneys. The transplanted kidney is placed inthe iliac fossa (of the pelvis) for support.

Kidney StonesKidney stones (renal calculi) are concretions that form inthe kidneys and may lodge in the calices, ureters, or urinarybladder. Kidney stones may block urine passage and causepain referred to nearby regions.


Vessels of the kidneys and ureters


Right and left renal Abdominal • Gives rise to 4–5 segmental arteriesaorta • Supply superior aspect of ureter

Segmental (4–5) Renal arteries Supply segments of the kidney

Right and left Abdominal Supply middle aspects of uretergonadal (testicular aortaor ovarian)

Abdominal aorta Continuous Supply inferior aspects of ureterwith thoracic aorta

Vein Termination Description

Renal Inferior vena Drain kidneys and ureterscava

Gonadal • Right gonadal Drain uretersterminates in inferior vena cava

• Left gonadal terminates in left renal vein


Additional ConceptParasympathetic InnervationParasympathetic innervation of the kidneys is negligible.Autonomic innervation of the ureters is modulatory, but notnecessary to maintain the peristaltic contractions that con-vey urine to the bladder.

SUPRARENAL GLANDS

Structure of the suprarenal glandsThe suprarenal glands are positioned between the kidneysand crura of the diaphragm.The right gland is pyramidal-shaped, whereas the left is crescent-shaped. They are sur-rounded by perirenal fat and renal fascia and separatedfrom the kidney connective tissue. The suprarenal glandsfunction to secrete hormones and norepinephrine andepinephrine.


Nerves of the kidneys and ureters


Sympathetic Presynaptics originate • Presynaptic sympathetics are intermediolateral cell conveyed to the renal, abdominalcolumn of the spinal aortic and superior hypogastriccord travel in sympa- plexuses/gangliathetic trunks and • Postsynaptic fibers travel on splanchnic nerves to arterial branches to kidney and reach abdominal ureter; regulate blood pressureplexuses by effecting renin release

Visceral Cell bodies located Mediate pain sensationafferent in spinal ganglia


Cortex Outer part Secretes corticosteroids and androgens

Medulla Inner part • Secretes norepinephrine and epinephrine

• Composed of modified postsynaptic sympathetic neurons


ABDOMINAL LYMPHATICS

Vessels of the suprarenal glands(Figure 2-4)

Artery Origin DescriptionInferior phrenic Abdominal Gives rise to superior suprarenal

aorta

Superior suprarenal Inferior phrenic Part of rich blood supply to gland

Middle suprarenal Abdominal

Renal aorta Gives rise to inferior suprarenal

Inferior suprarenal Renal Part of rich blood supply to gland

Vein Termination DescriptionRight suprarenal Inferior vena Drain gland

cava

Left suprarenal Left renal

Nerves of the suprarenal glands

Nerve Origin Structures innervatedSympathetic Presynaptics originate Presynaptic sympathetics are

from the intermediola- conveyed to the suprarenal glands teral cell column of the by traveling on arterial branches,spinal cord and travel where they synapse on cells of the in the sympathetic medullatrunks and splanchnic nerves to reach abdominal plexuses

Structure Description DrainageAbdominal wall Superficial lymphatic vessels • Superior to umbilicus—

accompany subcutaneous drain to axillary nodesveins • Inferior to umbilicus—

drain to superficial inguinal nodes

Esophagus Into left gastric lymph Left gastric nodes drain into nodes celiac nodes

Stomach Vessels accompany arteries Lymph is collected in gastric along curvatures of stomach and gastro-omental nodes,

which drain into pancreaticos-plenic, pyloric, and pancreati-coduodenal lymph nodes, all of which eventually drain to the celiac nodes

Abdominal lymphatics

(continued)

74



Structure Description Drainage

Abdominal lymphatics (continued)

Small intestine • Duodenum: vessels • Duodenum: anterior vesselsaccompany arteries drain into pancreaticoduo-

• Jejunum and ileum: denal nodes, which drain drainage begins as special- into pyloric nodes; posterior ized vessels—lacteals in vessels drain into superior the intestinal villi mesenteric nodes, all of

which eventually drain into celiac nodes

• Jejunum and ileum: lacteals form vessels that drain into juxta-intestinal nodes to mesenteric nodes to superior central nodes, all of which eventually drain into superior mesenteric lymph nodes that drain to the ileocolic nodes

Large intestine • Cecum and appendix: • Cecum and appendix: nodes vessels to the nodes in the in the mesoappendix and mesoappendix and ileocolic ileocolic nodes drain to the lymph nodes superior mesenteric nodes

• Ascending, descending, • Ascending, descending,and sigmoid colon: vessels and sigmoid colon: epiploicto epicolic and paracolic and paracolic nodes drain nodes to ileocolic and right colic

• Transverse colon: vessels nodes, which drain to to middle colic nodes superior mesenteric lymph

• Rectum: superior half: nodesdrain to pararectal nodes; • Transverse colon: middle inferior half: drain to colic nodes drain to super-sacral nodes ior mesenteric nodes

• Anal canal: superior to • Rectum: pararectal nodes pectinate line: drain to drain to inferior mesentericinternal iliac nodes; nodes, sacral nodes followinferior to pectinate line: middle rectal vessels to drain to superficial inguinal internal iliac nodesnodes • Anal canal: internal iliac

nodes drain to the common iliac and eventually the lumbar lymph nodes; superficial inguinal nodes drain to the deep inguinal lymph nodes

Spleen Vessels follow arteries from Vessels lead to the hilum pancreaticosplenic nodes,

which lead to superior mesenteric lymph nodes

(continued)


Additional ConceptThoracic DuctThe thoracic duct begins in the abdomen as the cisternachyli and conveys lymph from both lower limbs, the entireabdomen, the left half of the thoracic cavity via a thoracictrunk, the left upper limb via a subclavian trunk, and leftside of the head and neck via the jugular trunk to the junc-tion of the subclavian and internal jugular veins.

Right Lymphatic DuctThe right lymphatic duct conveys lymph from the remain-der of the body (right side of thorax via a thoracic trunk,right upper limb via a subclavian trunk, right side of headand neck via a jugular trunk) to the junction of the internaljugular and subclavian veins on the right.

Lymphatic vessels associated with abdominal visceragenerally follow vessels (arteries) and are conveyed to lum-bar and intestinal lymphatic vessels/trunks, which lead to thecisterna chyli.


Structure Description Drainage

Abdominal lymphatics (continued)

Pancreas Vessels follow arteries Vessels lead to pancreatico-splenic nodes and pyloricnodes, which lead to the sup-erior mesenteric lymph nodes

Suprarenal Drain to lumbar lymph nodesglands

Kidney and Kidney and superior aspect • Kidney and superior aspect ureter of ureter: vessels follow of ureter: drain to the

arteries lumbar nodes• Mid-ureter: drain to

common iliac nodes• Inferior ureter lymph is con-

veyed to iliac lymph nodes

Gall bladder Lymphatics are first conveyed Lymph from hepatic nodes is to the hepatic nodes conveyed to celiac nodes

Liver Efferent lymphatics drain to • Produces �50% of the the hepatic nodes (deep lymph conveyed by the lymphatics), to phrenic nodes thoracic duct(superficial lymphatics) or • Most lymph from the liverposterior mediastinal nodes is conveyed to the cisterna

chyli—the dilated begin-ning of the thoracic duct


INTRODUCTIONThe pelvic cavity is the inferior portion of the abdomino-pelvic cavity and as such has many features and structures incommon with the abdominal cavity; many organs and peri-toneal relations are continuous between the two. The pelviccavity contains parts of the urinary system and the internalgenitals.

The perineum is the area between the thighs and thelocation of the external genitalia in both sexes.

PELVIS

3Pelvis

77

Area Structure SignificancePelvic inlet (superior pelvic aperture)

Pelvic outlet

Areas of the pelvisThe pelvic cavity is continuous superiorly with the abdomi-nal cavity.

Bounded by: • Pubic symphysis and

crest• Pectineal line• Arcuate line of the

ilium and the ala ofeach side

• Promontory of thesacrum

Bounded by:

• Pubic symphysis• Ischiopubic ramus and

ischial tuberosity• Sacrotuberous

ligaments• Coccyx

Collectively the structuresthat bound the pelvic inletare known as the lineaterminalis or pelvic brim

In the female, the pelvicoutlet is larger than in themale to accommodateparturition

(continued)


Clinical SignificancePregnancyThe size of the lesser pelvis increases and the pubic symph-ysis becomes more flexible in pregnant females as hormonescause the pelvic ligaments to relax.


Area Structure SignificanceGreater pelvis (false pelvis)

Lesser pelvis (true pelvis)

Retropubic space

Retrorectal space

Areas of the pelvis (continued)

Bounded by:

• Lateral—ala of theilium

• Inferior—pelvic inlet• Superior—continuous

with abdominal cavity• Anterior—abdominal

wall• Posterior—L5–S1

vertebrae

Bounded by:

• Superior—pelvic inlet(superior pelvicaperture)

• Inferior—pelvic outletand pelvic diaphragm

• Lateral—hip bones• Posterior—sacrum and

coccyx• Anterior—pubic

symphysis

Potential, fat-filled area ofendopelvic fascia betweenthe pubic symphysis andurinary bladder

Potential, fat-filled area ofendopelvic fascia betweenthe rectum and sacrumand coccyx

• Superior aspect of thepelvis

• Contains abdominalviscera, including thesigmoid colon and partsof the ileum

• Inferior aspect of thepelvis

• Contains reproductive andurinary organs, includingthe urinary bladder,uterus (female), andprostate (male)

Allows for the expansion ofthe urinary bladder as it fillswith urine

Allows for the expansion ofthe rectum during defecation

Feature Characteristic SignificancePelvic girdle

Bones of the pelvis(Figure 3-1)

Basin-shaped groupof bones: 2 hip bonesand the sacrum

• Transfers weight fromvertebral column to lowerlimbs

(continued)


CHAPTER 3 | PELVIS 79

Bones of the pelvis (continued)

Sacrospinousligament formsgreater sciatic notchinto foramen

Sacrospinous andsacrotuberousligaments formforamen

Formed by body andramus of ischium andsuperior and inferiorpubic rami

• Formed bycontributions fromthe ilium, ischium,and pubis

• Deficient inferiorlyas the acetabularnotch

Formed by bothischiopubic rami,which meet at thepubic symphysis

Ala

• Hip bones joined anteriorly bypubic symphysis, joined tosacrum posteriorly at sacroiliacjoints

Permits passage of piriformis,gluteal vessels, and nerves,sciatic and posterior femoralcutaneous nerves, internalpudendal vessels, pudendal nerve,and nerves to obturator internusand quadratus femoris from thepelvis to the gluteal region

Permits passage of the tendon ofobturator internus and the internalpudendal vessels and pudendalnerve as they wrap around theischial spine to enter theperineum

• Covered by obturatormembrane

• A deficiency in the obturatormembrane—the obturatorcanal: permits passage ofobturator vessels and nervesbetween the pelvis and lowerlimb

• Cup-shaped articular cavity onlateral aspect of hip bone

• Head of femur articulates here• Acetabular notch bridged by

transverse acetabularligament to complete cup

Inferior borders of ischiopubicrami form subpubic angle,which is typically �70� in malesand �80� in females

• Expanded upper portion of ilium• Superior border is the iliac

crest• Posterior gluteal surface bears

3 lines: the anterior, middle,

Feature Characteristic Significance

Greater sciatic foramen

Lesser sciatic foramen

Obturator foramen

Acetabulum

Pubic arch

Hip Bones—formed by the fusion of the ilium, ischium, and pubis

Ilium

(continued)



Feature Description Significance

Ischium


Body

Arcuate line

Iliac crest

Anterior superior iliacspine

Posterior superioriliac spine

Anterior inferior iliacspine

Posterior inferior iliacspine

Iliac fossa

Greater sciatic notch

Body

Ramus

Ischial tuberosity

and posterior gluteal linesthat serve as attachments formuscles of the gluteal region

• Anterior surface—iliac fossa

• The smaller inferior portion ofthe ilium

• Forms part of acetabulum

• Junction of the body of theilium and body of the ischium

• Part of linea terminalis

• Superior border of ala• Attachment for abdominal,

back, and lower limb muscles• Located between the anterior

and posterior superior iliacspines

• Anterior end of iliac crest• Attachment for fascia lata,

tensor of fascia lata, sartorius,and inguinal ligament

• Posterior end of iliac crest• Attachment for multifidus• Site of skin dimples• Marks S2 vertebral level and

inferior end of dural sac

Attachment for rectus femoris

Superior border of greater sciaticnotch

• Depression on anterior aspectof ala

• Proximal attachment for iliacus

Between posterior inferior iliacspine and ischial spine

• Forms part of acetabulum• Ischial spine and tuberosity

project from body

Articulates with inferior ramus ofpubis

• Projection from body of ischium• Attachment for adductor

magnus, the hamstrings, andthe sacrotuberous ligament

(continued)


The gluteal-aspect (posterior) of the bones in this table isdescribed with the skeletal sections of the lower limb andback.

Additional ConceptGreater Sciatic ForamenThe greater sciatic foramen is considered an exit from thepelvis. Of the structures passing out of the pelvis via theforamen, only the superior gluteal vessels and nerves passsuperior to the piriformis, all other structures pass inferiorto this landmark muscle.

Ischiopubic RamusThe ramus of the ischium and the inferior ramus of thepubis are collectively known as the ischiopubic ramus.



Pubis


Ischial spine

Body

Superior ramus

Pubic tubercle

Pectin pubis

Inferior ramus

• Projection from body• Attachment for superior

gemellus, coccygeus, levatorani, and sacrospinousligament—which convertsthe greater sciatic notch into aforamen

• Forms superior border of lessersciatic notch

Forms part of acetabulum

• Articulates with contralateralsuperior ramus

• Pubic tubercle projects fromsuperior ramus

• Contributes to obturatorforamen

• Projection from superior ramus• Attachment for inguinal

ligament and inferior crus ofsuperficial inguinal ring

• Ridge along superior ramusextending laterally from pubictubercle

• Attachment for lacunarligament and conjoint tendon

Contributes to obturator foramen


Clinical SignificanceSex Differences in the PelvesThe pelves differ between the sexes: the female pelvis is spe-cialized for parturition. The female pelvis is lightweight,wide, and shallow, with an oval pelvic inlet and larger pelvicoutlet and subpubic angle relative to the male pelvis.

Minimum diameters of the pelvis are important inobstetrics. The obstetric “true” conjugate—the distancebetween the posterior aspect of the pubic symphysis and thesacral promontory should be �11 cm for vaginal delivery.


Sacroiliacjoint

Coccyx

Neck offemur

Lessertrochanter

Anteriorsuperioriliacspine

Anteriorinferioriliacspine

Ischicalspine

Obturatorforamen

Fifth lumbarvertebra Sacrum Iliac crest

Body ofpubis

Symphysisof pubis

Ischialtuberosity

FIGURE 3-1. Bones of the pelvis radiograph. (From Dudek RW,

Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott


Joint Type Articulation StructureSacroiliac

Joints of the pelvis(Figure 3-1)

• Anteriorpart:synovial

Sacrumsuspendedbetweeniliac bones

• Joint strengthened byanterior, posterior, andinterosseous sacroiliacligaments

(continued)




Pubic sym-physis

Joints of the pelvis (continued)

• Posteriorpart:fibrous

Cartilaginous Betweenbodies ofpubic bones

• Sacrotuberous andsacrospinous ligamentsprovide resilient supportduring times of suddenweight increases (e.g., jumping)

• Interpubic disc locatedbetween bones

• Joint strengthened bysuperior and inferiorpubic ligaments; alsostrengthened by tendonsof rectus abdominis andexternal oblique

The joints associated with the vertebral column are described withthe back (see Chapter 4).

Feature Description SignificanceFemaleSupravesical fossa

Vesicouterine pouch

Rectouterine pouch

Peritoneum of the pelvis(Figure 3-6)

The peritoneum lining the greater sac of the abdomen con-tinues into the pelvis; it reflects onto the organs of the pelviscreating pouches and fossae.

Between anteriorabdominal wall andurinary bladder

Between urinary bladderand uterus

Between uterus andrectum

Reflection of peritoneumfrom anterior abdominal wall onto superior surface of urinary bladder • Allows for expansion of

urinary bladder

• Reflection of peritoneumfrom urinary bladder ontouterus

• Allows for expansion ofuterus and urinarybladder

• Potential site for fluidaccumulation duringpathologic processes

• Reflection of peritoneumfrom uterus to rectum

(continued)



Fascia/Connective Tissue Significance/StructurePelvic fascia

Parietal layer of pelvicfascia

Visceral layer of pelvicfascia

Tendinous arch of pelvic fascia

Puboprostatic ligament

Pubovesical ligament

Endopelvic fascia

Fascia of the pelvis (Figure 3-6)

• Inferior continuation of endoabdominal fascia• Between parietal peritoneum and muscular body

wall

Membranous layer of pelvic fascia that lines themuscles of the pelvic walls

Membranous layer of pelvic fascia that invests theorgans of the pelvis as their adventitial layer

Anteroposterior oriented bilateral thickening of pelvicfascia formed at points of reflection between theparietal and visceral layers of pelvic fascia (justlateral to where organs penetrate pelvic floor)

Anterior subdivision of tendinous arch in the malethat connects the prostate to the pubis

Anterior subdivision of tendinous arch in the femalethat connects the neck of the bladder to the pubis

Layer of fascia connecting the visceral and parietallayers of pelvic fascia of varying consistency


MaleSupravesical fossa

Rectovesical pouch

Peritoneum of the pelvis (continued)

Between anteriorabdominal wall andurinary bladder

Between urinary bladderand rectum

• Allows for expansion ofrectum and uterus


Reflection of peritoneumfrom anterior abdominal wallonto superior surface ofurinary bladder • Allows for expansion of

urinary bladder

• Reflection of peritoneumfrom urinary bladder ontorectum

• Allows for expansion ofrectum and urinary bladder


(continued)


Fascia/Connective Tissue Significance/StructureTransverse cervical (cardinal) ligament

Rectovesical septum

Prostatic sheath

Fascia of the pelvis (continued)

• Condensed layer of endopelvic fascia in the femalethat provides the primary support for the uterus

• Connects lateral wall of pelvis with the cervix ofthe uterus

Condensed layer of endopelvic fascia in the malebetween the bladder and prostate and the rectum

• Formed by the visceral layer of pelvic fascia• Surrounds fibrous capsule of the prostate• Continuous anteriorly with the puboprostatic

ligaments and posteriorly with the rectovesicalseptum

Muscles of the pelvis(Figures 3-2, 3-3, and 3-6)

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsObturator internus

Piriformis

Levator ani (iliococcygeus, pubococcygeus [largest part] and puborectalis)

Coccygeus

Obturatormembrane,ilium, andischium

Sacrum(S2–S4segments),sacrotuber-ous ligament,margin ofgreatersciatic notch

Pubis,tendinousarch ofobturatorinternus andischial spine

Ischial spine

Greatertrochanter offemur

Perinealbody, coccyx,anococcygealligament,walls ofprostate,vagina,rectum andanal canal

Sacrum andcoccyx

Nerve toobturatorinternus(L5–S2)

S1–S2

Pudendaland nerve tolevator ani

S4–S5

Laterallyrotates thigh,holds femurin acetabulum

Laterallyrotates andabductsthigh; holdsfemur inacetabulum

• Part ofpelvicdiaphragm

• Supportspelvicviscera

• Puborec-talis partforms slingaroundanorectaljunction—responsiblefor fecalcontinence

Part of pelvicdiaphragm • Supports

pelvicviscera


Additional ConceptPelvic DiaphragmThe pelvic diaphragm is the funnel-shaped floor of thepelvis, formed by the levator ani and coccygeus.The levatorani is subdivided based on attachment into iliococcygeus,pubococcygeus, and puborectalis from superior to inferior.

Obturator FasciaA thickening of the fascia of the obturator internus—theobturator fascia on the medial surface of the muscle—forms the tendinous arch of levator ani, which serves asan attachment for levator ani.

Sacral PlexusThe sacral plexus sits on the muscular “bed” of the piri-formis.

Clinical SignificanceTrauma to the Pelvic FloorThe muscles forming the floor of the pelvis may be injuredduring childbirth. Trauma to the pubococcygeus, the mainpart of the levator ani or the nerves supplying it, may leadto urinary incontinence.


Nerves of the pelvis(Figures 3-2, 3-3, and 3-6)

The lumbosacral trunk conveys fibers from the L4–L5spinal cord levels to the sacral plexus (S1–S4). The sacralplexus innervates pelvic structures, the perineum, and thelower limb; it is formed of anterior rami.

Nerve Origin Structures InnervatedSacral PlexusSciatic

Pudendal

Superior gluteal

Inferior gluteal

L4–S3

S2–S4

L4–S1

L5–S2

Supplies hip joint, leg, foot andposterior compartment of the thigh

• Supplies perineal musculature,sphincter urethrae, and external analsphincter

• Sensory to skin covering externalgenitalia

Supplies gluteus medius and minimusand tensor of fascia lata

Supplies gluteus maximus

(continued)


Nerves of the pelvis (continued)

Supplies piriformis

Supplies quadratus femoris and inferiorgemellus

Supplies obturator internus andsuperior gemellus

Supplies levator ani and coccygeus

Sensory to inferior aspect of buttockand posterior aspect of thigh

Fibers join the hypogastric, pelvic,sacral, and coccygeal plexuses andfollow arteries to their targets—arteries, urinary bladder, prostate,seminal glands, uterus, vagina, andgenitals

Fibers join the hypogastric and pelvicplexuses and follow arteries to theirtargets—urinary bladder, rectum, andgenitals, where they synapse in thewall of the organ

The pelvic pain line is indicated bythe peritoneum as it drapes into thepelvis—structures in contact with theperitoneum are above the pain line;structures inferior to the peritoneumare below the pain line

S1–S2

L4–S1

L5–S2

S3–S4

S2–S3

Sacral levels ofthesympathetictrunks conveypostsynapticsympatheticfibers, andsacralsplanchnicnerves toplexuses in thepelvis

S2–S4 containpresynapticparasympathe-tic fibers thatare conveyedvia pelvicsplanchnicnerves toplexuses in thepelvis

Inferior topelvic pain line:conveysensation toS2–S4 levelsvia pelvicsplanchnics;superior topelvic pain line:conveysensation tothoracic andlumbar spinalcord levels

87

Nerve Origin Structures InnervatedNerve to piriformis

Nerve to quadratus femoris

Nerve to obturator internus

Nerve to levator ani

Posterior femoral cutaneous

Coccygeal Plexus—sparse fibers from lower sacral and coccygeal spinalcord levels that inconsistently provide sensory and motor innervation tonearby regions and structures.

Autonomic Innervation of the PelvisSympathetic

Parasympathetic

Visceral afferents


Clinical SignificanceCompression of the Sacral PlexusThe fetal head may compress branches of the sacral plexusduring pregnancy and childbirth, producing pain in thelower limbs and back.

MnemonicPudendal Nerve RootsPudendal and parasympathetic spinal cord levels:S2, S3, and S4 keep the genitals off the floor.


Iliolumbar artery

Obturatornerve

Superiorglutealnerve

Internal iliacartery and

vein

Lumbosacraltrunk

Psoas major

Pelvic splanchnicnerves

Medial view from left

Sciaticnerve

Inferior glutealartery

Pudendalnerve

Sympathetictrunk andganglion

Ramicommunicantes

Lateralsacralartery

Nerves topiriformis

Coccygealplexus

Coccygeus

Sacralplexus

S4

S5

FIGURE 3-2. Nerves of the pelvis. Somatic nerves (sacral and coc-

cygeal nerve plexuses) and the pelvic (sacral) part of the sympa-

thetic trunk are shown. Although located in the pelvis, most of the

nerves seen here are involved with the innervation of the lower limb

rather than the pelvic structures. (From Moore KL, Dalley AF.

Clinically Oriented Anatomy. 5th ed. Baltimore: Lippincott Williams

& Wilkins; 2006:380.)



Vasculature of the pelvis(Figures 3-2, 3-3, 3-4, and 3-6)

Common iliac

Internal iliac

Anterior division

Umbilical

Anterior division

Posteriordivision

Abdominalaorta

Supplies pelvis, gluteal region, thigh, andperineum

Supplies pelvic viscera and medialcompartment of the thigh

Supplies walls of pelvis and gluteal region

• Gives rise to superior vesical andoccasionally uterine and vaginal arteries

• Obliterated distal part forms medialumbilical ligaments

Supplies superior aspect of medialcompartment of thigh

Supplies urinary bladder

Supplies urinary bladder, prostate, seminalgland, and ureter

Supplies rectum, seminal gland, andprostate

Supplies superior aspect of gluteal region

Supplies inferior aspect of gluteal region

Supplies perineum

• May arise from anterior division orumbilical; may branch from common trunk

• Supply uterus and vagina, respectively

Supplies iliacus, psoas, quadratuslumborum, and vertebral canal

Supplies piriformis and vertebral canal

Supply testes and ovaries

Additional ConceptVenous DrainageVenous drainage generally parallels arterial supply.

Artery Origin DescriptionInternal iliac

Anterior division

Posterior division

Umbilical

Obturator

Superior vesical

Inferior vesical

Middle rectal

Superior gluteal

Inferior gluteal

Internal pudendal

Uterine/vaginal

Iliolumbar

Lateral sacral

Gonadal (testicular or ovarian)

Veins—veins draining to caval system generally follow arteries to terminatein the internal iliac vein; veins following portal system contribute to theinferior mesenteric vein



Common iliac artery

Internal iliac artery

External iliac artery

Obturator artery

Medial umbilicalligament

(obliteratedumbilical artery)

Superior vesicalarteries

A

B

Medial umbilical ligament

(obliteratedumbilical artery)

Superior vesicalarteries

Iliolumbar artery

Lateral sacral artery

SuperiorInferior

Internal pudendal arteryPudendal nerve

Internal pudendal arteryPudendal nerve

Glutealarteries

Iliolumbar artery

Lateral sacral artery

Inferior vesicalartery

Middle rectalartery

Middle rectalartery

Uterine artery

Vaginal artery

Common iliac artery

Internal iliac artery


Obturator arterySuperiorInferior

Glutealarteries

FIGURE 3-3. Arteries of the pelvis.The arteries of the male pelvis

(A) and the female pelvis (B) are shown. Anterior divisions of the

internal iliac arteries usually supply most of the blood to pelvic

structures.The arteries are internal (lie medial) to the nerves mak-

ing up the sacral plexus. (From Moore KL, Dalley AF. ClinicallyOriented Anatomy. 5th ed. Baltimore: Lippincott Williams &

Wilkins; 2006:386.)

Lymphatics of the pelvis

Structure Description DrainageUrinary bladder

Vesselsaccompany

• Superior aspect: external iliac nodes• Inferior aspect: internal iliac nodes

(continued)


URINARY BLADDER

Structure of the urinary bladder (Figures 3-3 and 3-6)

The bladder is a hollow, muscular organ that serves as reser-voir for urine until it is voided. When empty, it is locatedentirely within the lesser pelvis; when full, it may extendthrough the extraperitoneal fascial plane superiorly as highas the umbilicus.


Lymphatics of the pelvis (continued)

Structure Description DrainageUreters

Urethrae

Seminal glands

Prostate

Penis

Vagina

Uterus

Ovaries

Vulva

Vessels drain to internal and external commoniliac and lumbar nodes owing to their longcourse

• Male: vessels from prostatic andmembranous portions drain to internal iliacnodes, whereas those from the penileurethra drain to the deep inguinal nodes

• Female: vessels drain to the sacral andinternal iliac nodes

External and internal nodes

Internal iliac and sacral nodes

Superficial and deep inguinal and external andinternal iliac nodes

• Superior aspect: internal and external iliacnodes

• Middle aspect: internal iliac nodes• Inferior aspect: sacral and common iliac nodes• Drainage from the external vaginal orifice to

superficial inguinal nodes

• Fundus: lumbar nodes• Body: external iliac nodes• Cervix: internal iliac and sacral nodes

Lumbar nodes

Superficial inguinal nodes

arteries—generallystructuresdrain intoexternal andinternal iliacnodes, whichdrain intocommon iliacnodes to thelumbar nodes

Structure Description SignificancePartsBody Main part, between the

apex and fundus• In males—related to the

rectum• In females—related to the

vagina

(continued)


Additional ConceptPeritoneal RelationsThe urinary bladder is covered only on its superior surfacewith peritoneum; the remainder is covered with loose con-nective tissue (vesical fascia). The bladder is relatively freeexcept at the neck where it is held in place by the tendinousarch of the pelvis.

Median Umbilical FoldThe median umbilical ligament (vestige of the fetal ura-chus) is covered by peritoneum to form the median umbil-ical fold.


Structure Description SignificanceApex

Neck

Fundus

FeaturesDetrusor muscle

Internal urethral sphincter

Internal urethral orifice

Urinary trigone

Part directed toward thepubic symphysis

Inferior-most part

Convex, posteriorly-directed part

• Composes the muscularpart of the bladder wall

• Internal wall coveredwith rugae to allow forexpansion

Formed of circularlydisposed smooth musclesfibers

• Internal opening of theurethra

• Located at inferior“corner” of urinary trigone

Smooth inferoposterioraspect of bladder wall

• Anterior-most aspect• Part from which the

urachus—embryologicshunt for urine, originates

Anchored in place by thelateral ligaments of thebladder and the tendinousarch of pelvic fascia

• Also known as the base• Location of the ureters as

they enter the bladder

Innervated by theparasympathetics S2–S4,causes constriction of walland expulsion of urine

• Located near neck ofbladder

• Contract during ejaculationto prevent semen fromentering bladder

Radially arranged smoothmuscle fibers assist inopening the sphincter toexpel urine

3 corners of trigone: Inferior—internal urethralorifice and 2 superior—ureteric orifices

Structure of the urinary bladder (continued)


Additional ConceptVenous DrainageVenous drainage generally parallels arterial supply to end inthe internal iliac vein.


Artery Origin DescriptionSuperior vesical

Inferior vesical

Vaginal

Obturator

Inferior gluteal

Vasculature of the urinary bladder

Umbilical

Internal iliac

Uterine (sometimes viacommon trunk),umbilical, or internal iliac

Internal iliac

Supply anterior and superioraspects

Males: supply posterior andinferior aspects

Females: supply posterior andinferior aspects

May supply branches to bladder

Nerves of the urinary bladder

Nerve Origin Structures InnervatedParasympathetic S2–S4, Motor to detrusor, inhibitory to internal

conveyed via urethral sphincterpelvic splanch-nic nerves to pelvic plexuses

Sympathetic Presynaptics Motor to internal urethral sphincteroriginate from the intermedio-lateral cell column of the spinal cord and travel in the sympathetic trunks and splan-chnic nerves to reach pelvic plexuses

Visceral afferents Bladder wall • Senses stretching of bladder wall, impulses conveyed to spinal cord via pelvic splanchnics from most of bladder

• Superior part of bladder is superior to pelvic pain line so impulses are conveyed via sympathetic system


URETHRAE

Structure of the urethrae(Figures 3-3 and 3-6)

The urethrae extend from the internal urethral orifice of theurinary bladder to the external urethral orifice in bothsexes.They function to convey urine from the urinary blad-der to the outside world.


Structure Description SignificanceFemale urethra • External urethral orifice • Located anterior to the

located in the vestibule of vaginathe vagina • Urethral glands open along

• Passes through pelvic and lengthurogenital (external ure- • Paraurethral glands open thral sphincter) diaphragms near external urethral orifice

Male urethra • External urethral orifice • Common route for urine located on tip of glans and semenpenis • Divided into 4 parts:

• Passes through pelvic and 1. Intramural (preprostatic)urogenital (external ure- 2. Prostaticthral sphincter) diaphragms 3. Membranous

4. Penile (spongy)

Clinical SignificanceCatheterizationThe short, distensible female urethra allows for easy passageof catheters into the bladder and provides an easy route forbacterial infection of the bladder.

Artery Origin DescriptionFemaleInternal Anterior division Supplies urethra and perineumpudendal of internal iliac

Vaginal Supplies urethra and vagina

MaleInferior Anterior division Supply intramural and prostatic parts via vesical of internal iliac prostatic branches

Middle rectal

Internal Supplies membranous and penile partspudendal

Vasculature of the urethrae




FEMALE GENITALIA

Nerves of the urethrae

Nerve Origin Structures InnervatedParasympathetic Presynaptics originate Inhibitory to internal urethral

in spinal cord levels sphincterS2–S4, conveyed via pelvic splanchnic nerves to pelvic plexuses

Sympathetic Presynaptics originate Motor to internal urethral from the intermedio- sphincterlateral cell column of the spinal cord and travel in the sympathe-tic trunks and, finally, sacral splanchnic nerves to reach pelvic plexuses

Visceral Urethra Impulses conveyed to spinal cord afferents—both via pelvic splanchnics sexes

Somatic Pain and general tactile impulses afferents—both conveyed to spinal cord via pu-sexes dendal nerve

Structure Description SignificanceVaginaOverall • Extends from the uterus to • Vaginal vestibule—cleft

the vaginal vestibule between labia minora• Continuous superiorly with • Forms inferior part of birth

cervical canal at the canal, route for menses, external os of the uterus and receives erect penis

• Vaginal fornices (anterior, during copulationlateral, and posterior) • Relations: surround uterine cervix • Anterior—bladder

• Posterior—rectum• Lateral—levator ani

Internal genitalia of the female(Figures 3-3 and 3-4)

(continued)




Internal genitalia of the female (continued)

Vessels • Arterial supply: uterine, Origin of arteries: anterior vaginal, and internal division of internal iliacpudendal

• Venous drainage: via vaginal plexus to utero-vaginal venous plexus to internal iliac veins

Innervation • Motor: superior aspect— • Visceral: uterovaginal nervevisceral, inferior aspect— plexus contains sympa-somatic thetics from the intermedio-

• Sensory: superior aspect— lateral cell column, visceral, inferior aspect— conveyed via the sympatheticsomatic chain and parasympathetics

from S2–S4 spinal cord levels conveyed via pelvic splanchnics, visceral afferents travel with pelvic splanchnics

• Somatic: pudendal nerve

UterusOverall • Structure: • Thick-walled, muscular

• Fundus: superior to organuterine tubes • Uterine cervix projects

• Body: main part, contains into superior aspect of uterine cavity vagina where it is

• Isthmus: narrow region surrounded by the vaginalsuperior to cervix fornices

• Cervix: possesses cervi- • The uterus is supported bycal canal with superior ligaments (condensations and inferior openings: of pelvic fascia) near thethe internal and cervix—the transverse external os cervical (cardinal) and

• Relations: uterosacral ligaments • Anterior: bladder with

intervening vesicouterine pouch

• Posterior: rectum with intervening rectouterine pouch

Vessels • Arterial supply: uterine Origin of arteries: anterior and ovarian division of internal iliac

• Venous drainage: via uterine plexus to utero-vaginal plexus to internal iliac veins

(continued)





Innervation Innervation is from utero- Uterovaginal nerve plexus vaginal plexus contains sympathetics from

the intermediolateral cell column, conveyed via the sympathetic chain and parasympathetics from S2–S4 spinal cord levels conveyed via pelvic splanchnics, visceral afferents for pain travel with sympathe-tics above the pelvic pain line and with pelvic splanch-nics below the pelvic pain line

Uterine TubesOverall • Bilateral; extend from the • Infundibulum—

junction of the fundus and funnel-shaped end near body of the uterus to open ovary, possesses fimbriae: into the peritoneal cavity finger-like processes that adjacent to the ovaries envelope the medial pole

• Divided into infundibulum, of the ovaryampulla, isthmus, and • Ampulla—longest part,uterine parts normal site of fertilization

• Isthmus—part that enters the uterus

• Uterine part—intramural

Vessels • Arterial supply: ovarian Origin of arteries: abdominal arteries aorta

• Venous drainage: empties into the ovarian veins and the uterovaginal venous plexus

Innervation Innervation is from uterine Contain sympathetics from and pelvic plexuses the intermediolateral cell

column, conveyed via the sympathetic chain and parasympathetics from S2–S4 spinal cord levels conveyed via pelvic splanchnics, visce-ral afferents travel with sym-pathetics as the uterine tubesare above the pelvic pain line,some visceral afferents travel with pelvic splanchnics to mediate reflexes

(continued)


Additional Concept UterusThe uterus is typically anteverted (tipped anteriorly relativeto the vagina) and anteflexed (body is flexed anteriorly rela-tive to the cervix), but variations in degree and position arecommon.

The uterus is covered by peritoneum, which extends lat-erally off the uterus to the walls of the pelvis as the broadligament. The broad ligament conveys uterine neurovascu-lar elements between its layers and contains the ovaries and




Ovaries

Overall • Located along lateral walls • Not covered by peritoneumof pelvis • The oocyte is ovulated into

• Held in relatively stable the peritoneal cavityposition by the meso- • Fimbriae of the uterine varium, suspensory tubes and the ciliated ligament of the ovary, lining of the uterine tubesand the ligament of typically guide the oocyte the ovary into the ampulla of the

uterine tube

Vessels • Arterial supply: ovarian • Origin: abdominal aortaarteries • The pampiniform plexus

• Venous drainage: small of veins forms a pair of veins drain to a pampini- ovarian veins, the right form venous plexus located ovarian vein empties within the broad ligament into the inferior vena

cava, whereas the left drains into the left renal vein

Innervation Innervation is from uterine Contain sympathetics from and pelvic plexuses the intermediolateral cell

column, conveyed via the sympathetic chain and para-sympathetics from S2–S4 spinal cord levels conveyed via pelvic splanchnics, visceral afferents travel with sympathe-tics as the uterine tubes are above the pelvic pain line, some visceral afferents travel with pelvic splanchnics to mediate reflexes


uterine tubes. The suspensory ligament of the ovary is asuperolateral extension of the broad ligament from theovary that conveys the ovarian vessels.The ligament of theovary is found within the broad ligament and connects theovary to the uterine body, whereas the round ligament ofthe uterus, also found within the broad ligament, projectsfrom the uterine body through the inguinal canal to termi-nate as connective tissue septa in the labia majora. A poste-rior extension of broad ligament invests the ovary—the mesovarium, an extension of the broad ligamentinvests the uterine tube—the mesosalpinx. Inferior to themesosalpinx the broad ligament is referred to as themesometrium.

Embryologic OriginsThe ligament of the ovary and the round ligament of theuterus are vestiges of the embryologic ovarian gubernacu-lums and are the equivalent of the very short scrotal liga-ment in the male.


Structure Description SignificanceMons Pubis, Labia Major, and Labia MinoraOverall • Mons pubis and labia The labia minora are

majora are prominent, connected anteriorly, the fatty, pubic hair covered posterior aspect of this eminences surrounding connection forms the the pudendal cleft frenulum of the clitoris,

• The labia minora are thin, whereas the anterior portionfat-free folds of skin that forms the prepuce of theenclose the vaginal vesti- clitoris, posteriorly they are bule united to form the frenulum

of the labia minoraVessels • Arterial supply: labial • Origin of arteries: internal

branches pudendal• Venous drainage: parallels • During sexual arousal—

arterial supply enlarge as a result of increased blood in under-lying structures

Innervation Pudendal Pudendal and its branches (anterior and posterior labial) are chief source of sensory innervation

External genitalia of the female(Figure 3-4)

(continued)




External genitalia of the female (continued)

ClitorisOverall Parts: root and body; • The corpora cavernosa

composed of 2 crura made diverge posteriorly to form of 2 erectile cylinders—the crura that attach to corpora cavernosa and ischiopubic rami for supportthe glans of the clitoris and are invested by the

ischiocavernosus muscles• The glans is the most

sensitive part of the heavily innervated clitoris

Vessels • Arterial supply: clitoral • Origin of arteries: internal branches pudendal

• Venous drainage: parallels • Sexual arousal causes arterial supply engorgement and enlarge-

ment from increased arterialsupply and decreased venous return

Innervation Pudendal and uterovaginal • Pudendal branches (dorsal plexus nerve of the clitoris) provide

somatic sensation• Parasympathetics from

uterovaginal plexus cause erection

Bulbs of the Vestibule and Vestibular GlandsOverall • Bulbs of the vestibule are • Bulbospongiosus invests

masses of erectile tissue the bulbs of the vestibuleunderlying the labia majora • The vestibular glands

• Vestibular glands lie post- (greater and lesser) secreteerior to the bulbs mucus during sexual aro-

usal to moisten the vestibule

Vessels • Arterial supply: branches • Origin of arteries: internal of the internal pudendal pudendal

• Venous drainage parallels • Sexual arousal causes arterial supply engorgement and enlarge-

ment of the bulbs of the vestibule from increased arterial supply and decreased venous return

Innervation Uterovaginal plexus Parasympathetics from uterovaginal plexus cause erection and increased secretion from the glands


A

Infundibulum

Uterine tubeOvarianartery and

veinAmpulla

FimbriaeOvary

UreterUterine vein

Uterine arteryVaginal artery

and vein

Vaginal venous plexus

VaginaInternalpudendalartery

Ascendingbranchof uterineartery

Ligament of ovaryUterus

Isthmus

C

B

Uterinecavity

Ampullaof uterinetube

Vagina

FIGURE 3-4. Female pelvis. A: Diagram of the arterial supply and

venous drainage of the ovaries, uterine tubes, uterus, and vagina.

B: Anteroposterior radiograph of the female pelvis after injection of

a radiopaque compound into the uterine cavity (hysterosalpingogra-

phy). C: Diagram of the female genitalia. (From Dudek RW, Louis

TM. High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott


101


Structure Description SignificanceDuctus Deferens (2)Overall Begins in scrotum at tail of • Proximal continuation of

epididymis; ends by joining epididymisduct of seminal gland to • Ascends as part of sper-form ejaculatory duct matic cord; possesses an

ampulla—an expansion near its distal end

Vessels • Arterial supply: artery to Origin of arteries: superior the ductus deferens vesical artery

• Venous drainage parallels arteries

Innervation Innervation is from the Contains sympathetics from pelvic plexus the intermediolateral cell

column, conveyed via the sympathetic chain and sacral splanchnics and parasympa-thetics from S2–S4 spinal cord levels conveyed via pelvic splanchnics

Seminal GlandsOverall • Located between urinary • Secrete a thick alkaline

bladder and rectum— fluid that contributes to separated from it by the semenrectovesical pouch

• Duct joins with ductus deferens to form ejacula-tory duct

Vessels • Arterial supply: Origin of arteries: inferior small branches vesical and middle rectal

• Venous drainage parallels arteries

Internal genitalia of the male(Figures 3-3 and 3-5)

(continued)

Additional ConceptCollectively, the external genitalia of the female are referred toas the vulva or pudendum. The labia majora enclose aspace—pudendal cleft, which contain the labia minora andvaginal vestibule, whereas the labia minor enclose the vaginalvestibule, which contains the vaginal orifice, external ure-thral orifice (with openings of the ducts of the paraurethralglands on either side), and openings of the vestibular glands.

MALE GENITALIA




Internal genitalia of the male (continued)


column, conveyed via the sympathetic chain and para-sympathetics from S2–S4 spinal cord levels conveyedvia pelvic splanchnics

Ejaculatory DuctsOverall Formed by the union of the • Open near the prostatic

ductus deferens and the utricle in the prostatic duct of the seminal gland urethra

• Secrete fluid from the seminal gland and sperm from the ductus deferens

Vessels • Arterial supply: artery to Origin of arteries: superior the ductus deferens (or inferior) vesical artery

• Venous drainage is to prostatic and vesical venous plexuses


column, conveyed via the sympathetic chain and para-sympathetics from S2–S4 spinal cord levels conveyed via pelvic splanchnics

ProstateOverall Lobes: • Surrounds prostatic urethra

• Lateral (right and left)— Possesses fibrous capsule—largest, located on sides fibrous capsule of theof prostatic urethra prostate, which invests

• Isthmus—anterior to nerves and vessels supply-urethra, muscular continua- ing the gland and istion of internal urethral surrounded by the visceral sphincter layer of pelvic fascia—

• Posterior—posterior to prostatic sheath, pubopros-urethra, palpable via tatic ligaments, and therectum rectovesical septum

• Middle—between urethra • Prostatic ducts (20–30) and ejaculatory ducts; open into prostatic sinusesenlargement may interfere on the side of the seminalwith urination colliculus in the prostatic

urethra where they convey a milky alkaline secretion


(continued)


Clinical SignificanceVasectomyThe vasectomy (ligation of the ductus deferens) is a com-mon method of sterilization in the male.



Internal genitalia of the male (continued)

Vessels • Arterial supply: prostatic • Origin of arteries: internal arteries pudendal, middle rectal,

• Venous drainage is to pro- and inferior vesicalstatic plexus associated • Venous plexus drains with the fibrous capsule into internal iliac veins

and communicates with internal vertebral and vesical venous plexuses—potential routes for metastasis

Innervation Innervation is from the pelvic Contains sympathetics from plexus the intermediolateral cell


Bulbourethral Glands (2)

Overall Lie posterolateral to the The ducts of the bulbourethralmembranous urethra within glands pierce the perineal the external urethral membrane to open into the sphincter bulbous part of the penile

urethra, into which they secrete a mucus-like secretion

Vessels • Arterial supply: perineal Origin of arteries: internal branches pudendal

• Venous drainage parallels arterial supply




Lateral view

Ductus deferens

Testicular artery

Epididymis

head

tail

body

Testicular vein

(pampiniform venous plexus)

Cavity of

tunica vaginalis

Visceral layer o

tunica vaginalis

Septum

Seminiferous

tubule

Rete testis in

mediastinum of testis

Straight tubule

Parietal layer of

tunica vaginalis

Tunica albuginea

Efferent ductules

Spermatic cord

A

Prostate

External

urethral

sphincter

Seminal

colliculus

Urethral

crest

Prostatic

utricle

Perineal

membrane

Bulbourethral

glands

Openings of

prostatic ducts

into prostatic

sinuses

Opening of

ejaculatory duct

B

FIGURE 3-5. A: Testis and (B) prostate. (From Dudek RW, Louis


Williams & Wilkins; 2008:196.) 105


Enlargement of the ProstateHypertrophy of the prostate is common after middle ageand can interfere with urination. The seminal glands andprostate are easily palpable from the rectum. Cancer of theprostate affects 1 in 10 males.


Structure Description SignificancePenile UrethraOverall • Distal to the membranous • Membranous urethra

urethra traverses the deep • Begins at perineal mem- perineal pouch and is surr-

brane, ends at external ounded by the externalurethral orifice urethral sphincter

• Expansion at proximal end • Bulbourethral glandsin bulb of penis—the - open into proximal part, intrabulbar fossa and whereas urethral glandsat distal end—the open along length to navicular fossa lubricate urethra

Vessels • Arterial supply: dorsal Origin of arteries: internal artery of the penis pudendal artery

• Venous supply: parallels arterial supply

Innervation Pudendal nerve Pain and general tactile impulses conveyed to spinal cord via pudendal nerve

TestesOverall • Located in scrotum • Produce sperms and

• Outer layer—tunica testosteronealbuginea surrounded by • Tunica vaginalis is antunica vaginalis extension of peritoneum,

• An expansion of tunica divided into visceral layeralbuginea on posterior on surface of testis andaspect of testis forms parietal layer lining scrotalmediastinum testis, which wallsends septa into testicle • Seminiferous tubules areto form lobules site of sperm production

• Lobules contain semini- • Leydig cells in interstitialferous tubules that join tissue are site of test-posteriorly as straight osterone productiontubules that traverse the • Rete testis convey spermmediastinum as the rete to head of epididymis viatestis efferent ductules

External genitalia of the male(Figures 3-5 and 3-6)

(continued)



External genitalia of the male (continued)

Vessels • Arterial supply: testicular • Origin of arteries: abdominal(form part of spermatic aortacord) • Pampiniform plexus helps

• Venous drainage: pampini- with temperature regulationform plexus for sperm formation and

forms the left (empties into left renal vein) and right (empties into inferior vena cava) testicular veins

Innervation Parasympathetic and • Parasympathetics: from sympathetic fibers from vagustesticular plexus • Sympathetics: from thoracic

spinal cord and paraverte-bral chain

PenisOverall • Parts: root, body, and glans • The dorsal corpora caver-

• Formed of 3 cylinders of nosa are surrounded by aerectile tissue: 1 corpus thick tunica albuginea thatspongiosum and make for rigid erection,they2 corpora cavernosa separate into 2 crura proxi-that are surrounded by the mally and fuse with the deep fascia of the penis ischiopubic rami for support

• The ventrally located corpusspongiosum is traversedby the penile urethra andremains less rigid

Vessels • Arterial supply: deep and • Origin of arteries: internal dorsal arteries of the penis pudendal

• Venous drainage: blood • Deep dorsal vein conveysfrom the erectile tissues blood to the prostatic drains to deep dorsal vein plexus of veinsof penis, blood from remain-ing penile structures drains via the superficial dorsal veins to the external pud-endal vein

Innervation Receives parasympathetic, Contain sympathetics from sympathetic and sensory the intermediolateral cell fibers column, conveyed via the

sympathetic chain and para-sympathetics from S2–S4 spinal cord levels conveyed via pelvic splanchnics, affer-ents are carried by the dorsalnerve of the penis, a branch of the pudendal nerve

The scrotum is an outpocketing of the anterior abdominal walland is presented in Chapter 2.The testicles are presented with themale external genitalia.

107



Additional ConceptStructure of the PenisThe root of the penis is located in the superficial pouchand consists of: two crura—each formed of corpora caver-nosa, the single bulb—formed of an expanded proximalportion of the corpora spongiosa containing the proximalpenile urethra and the muscles covering each—the ischio-cavernosus invests the crura, whereas the bulbospongiosusinvests the bulb. The body (or shaft) of the penis is themain, pendulous part.The body expands on the distal end

Commoniliac artery

and vein

External iliacartery and vein

Cut edge ofperitoneum

Ductusdeferens

Retropubicspace

Urinarybladder

Deep dorsalvein of penis

Corpuscavernosum

Corpusspongiosum

Glanspenis

Externalurethral

orifice

Externalurethral

sphincter

Prostaticurethra

Spongyurethra

Internal analsphincter

Deep transverseperineal muscle

Ejaculatoryduct

Internalurethralorifice

Seminalgland

Rectum(ampulla)

Sciaticnerve

Ureter

Internaliliac arteryand vein

Rectovesicalpouch

Levator aniBulbourethralgland

Prostate

Scrotum

Testis

Bulb of penis

Epididymis

Testicular artery

Spermatic cord

Pampiniform venous plexus

Medial view

FIGURE 3-6. Male midsagittal through pelvis. (From Moore KL,

Dalley AF. Clinically Oriented Anatomy. 5th ed. Baltimore: Lippincott



of the penis to form the glans (or head) penis. The glansprojects proximally over the corpora to form the corona.The skin of the penis extends over the glans forming theprepuce. The external urethral orifice opens near the dis-tal tip of the glans.

Penile SupportThe penis is supported by the suspensory ligament ofthe penis—an extension of deep fascia that fuses with thedeep fascia of the penis. The fundiform ligament of thepenis is an extension of the membranous layer of superfi-cial fascia, which blends with the superficial fascia of thepenis.

Clinical SignificanceErection and EjaculationDuring erection, parasympathetic fibers relax thesmooth muscles in arteries supplying the corpora caver-nosa, allowing blood to flow in, whereas the bulbospon-giosus and ischiocavernosus impede venous return.During ejaculation, sympathetic fibers close the internalurethral sphincter, parasympathetic fibers cause contrac-tion of the smooth muscle of the urethra and the puden-dal nerve causes rhythmic contraction of the bulbospon-giosus.

Lymphatic DrainageThe lymphatic drainage of the testes follow the testicularvessels to lumbar lymph nodes, whereas lymphaticdrainage of the scrotum is to superficial inguinal lymphnodes.

PERINEUM


Area Structure SignificanceOverall Boundaries: • Diamond-shaped area

• Anterior—pubic symphysis between thighs• Posterior—coccyx • Divided into urogenital • Posterolateral— and anal triangles by a line

sacrotuberous ligaments drawn between the ischial• Anterolateral—ischiopubic tuberosities

ramus

Structure of the perineum

(continued)


The rectum and anal canal are presented with the large intestinein Chapter 2.

Additional ConceptPudendal Neurovascular ElementsBefore entering the pudendal canal, the pudendal nerveand internal pudendal vessels give off inferior rectal


Area Structure Significance

Structure of the perineum (continued)

Urogenital Anterior half of the diamond- Contains the scrotum and thetriangle shaped perineal region root of the penis in males

and the vulva in females

Anal triangle Posterior half of the Contains the anal canal and diamond-shaped perineal anus and the ischioanal region fossae in both sexes

Ischioanal • Wedge-shaped, fascial • The superiorly oriented fossae spaces between the apex is located along the

levator ani (medially), the tendinous arch of the obturator internus (laterally), levator aniand skin of the buttock • Fat-filled space traversed (inferiorly) by inferior rectal

• Anterior recess of fossae neurovascular elementsextend into deep perineal • Fat allows for expansion ofpouch anal canal, anus and rectum

during defecation

Pudendal canal • Passageway composed of Conveys pudendal nerve and obturator fascia along the internal pudendal vesselslateral wall of the ischio-anal fossa

• Begins at lesser sciatic notch and ends at the perineal membrane

Superficial Space between the perineal Contains roots of penis or perineal pouch membrane and membranous clitoris, ischiocavernosus and

layer of superficial fascia bulbospongiosus, superficial transverse perinei, greater vestibular glands (female), and deep perineal branches of internal pudendal vessels and pudendal nerve

Deep perineal Space between the perineal Contains anterior recess of pouch membrane and the inferior ischioanal fossa, deep

fascia of the pelvic transverse perinei, external diaphragm urethral sphincter, and part

of the urethra (and bulboure-thral glands in the male)


branches that course across the fossa to the rectum, analcanal, and anus.The pudendal nerve and internal pudendalvessels terminate by dividing into perineal (superficialpouch structures), dorsal artery and nerve of the penis orclitoris branches (deep pouch structures), and posteriorscrotal or labial branches.


Fascia/Connective Tissue Significance/StructureMembranous layer of • Along the posterior edge of the urogenital superficial fascia (Colles’) membrane, fuses with the perineal

membrane and perineal body• Laterally, fuses with the fascia lata of

the thigh; anteriorly, it is continuous with the membranous layer of superficial fascia of the abdomen (Scarpa’s)

Perineal membrane • Deep fascia spanning the urogenital triangle, investing the bulbospongiosus, ischiocavernosus, and transverse perinei muscles

• Pierced by the urethra and the vagina in the female

• Forms roof of superficial perinealpouch

Perineal body • Fibromuscular mass between the anus and perineal membrane

• Serves as an attachment for bulbospon-giosus, transverse perineal muscles, external anal sphincter, and levator ani

Fascia of the perineum

Additional ConceptThe fatty layer of superficial fascia in the perineum is con-tinuous with the fatty layer over the abdomen and makes upthe bulk of the two labia majora and mons pubis infemales.

Clinical SignificanceEpisiotomyDamage to the perineal body as may occur during child-birth, trauma, disease, or infection may lead to prolapse ofthe pelvic viscera. An episiotomy is performed during child-birth to enlarge the vaginal orifice and spare lasting damageto the perineal body.



Proximal DistalMuscle Attachment Attachment Innervation Main ActionsBulbo- Male— Male— Deep perineal Male—assistsspongiosus perineal body perineal mem- in erection and

and median brane, corpora ejaculation andraphe; female— spongiosum, emptying of perineal body and cavernosa urethra after

and fascia of micturition; bulb of penis; female—female— assists infascia of bulbs erectionof vestibule

Ischiocav- Ischiopubic rami Crura of penis Maintains ernosus and ischial or clitoris erection of

tuberosities penis or clitoris

External Coccyx via Perineal body, Inferior rectal Closes anus,anal anococcygeal surrounds supports sphincter ligament and anus perineal body

skin around anus and pelvic floor

External Ischiopubic rami Surrounds Deep Compresses urethral and ischial urethra; perineal urethra for the sphincter tuberosities males— maintenance of

ascends to urinary prostate, continencefemales—forms utero-vaginal sphincter

Deep Perineal body Fixes perineal transverse body to support perineal pelvic viscera

and resist intra-abdominal pressure

Superficial Ischial transverse tuberositiesperineal

Muscles of the perineum

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INTRODUCTIONThe back consists of the vertebral column, spinal cord andnerves, and the muscles responsible for posture and move-ment of the vertebral column.

VERTEBRAL COLUMN

Vertebral column structureThe vertebral column is composed of intervertebral disksand 33 vertebrae:

■ 7 cervical■ 12 thoracic■ 5 lumbar■ 5 fused sacral■ 4 fused coccygeal

The vertebral column protects the spinal cord and spinalnerves and supports the weight of the body.

Curvatures of the vertebral column

4Back

Curvature Description SignificanceCervical

Lumbar

Thoracic

Sacral

• Concave posteriorly (lordosis)• Secondary curvatures—cervical

develops when infant begins to holdup head, lumbar develops wheninfant begins to walk

• Concave anteriorly (kyphosis)• Primary curvatures—present at birth

Provideresiliency tovertebralcolumn

Additional ConceptAxial and Appendicular SkeletonThe axial skeleton is composed of the vertebral column,cranium, and thoracic cage (ribs, sternum, and hyoid bone).The appendicular skeleton is everything else (pectoral andpelvic girdles and the limbs).

113


Clinical SignificanceExcess CurvatureExcess thoracic kyphosis (humpback) is often caused byosteoporosis. Excess lumbar lordosis (sway back) is oftenseen in pregnancy. Scoliosis (crooked back) is a commonlateral deformity of the vertebral column in pubertal girls.


Normal Kyphosis Lordosis Normal Scoliosis

FIGURE 4-1. Curvatures of the vertebral column. (From Dudek

RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore:


Vertebrae Characteristic SignificanceTypical Body

Vertebral arch

• Most anterior; supports body weight,progressively larger as move inferiorlydown column

• Covered on superior and inferior surface byhyaline cartilage

• Peripheral border possesses epiphysialrim—a slight elevation that provideattachment for the annuli fibrosi of theintervertebral discs

• Posterior to the body• Formed by a pair of lamina and a pair of

pedicles• With the posterior aspect of the body, forms

the vertebral foramen—contains spinal cord

Structure of the vertebraeThe vertebrae generally increase in size as progress inferi-orly, a reflection of the increasing weight of the body.Vertebrae possess regional characteristics.

(continued)


CHAPTER 4 | BACK 115

Structure of the vertebrae (continued)

• Pair of platelike processes that form theposterior part of vertebral arch

• Meet posteriorly in the midline

• Pair of short processes that join vertebralarch to body

• Form anterior part of vertebral arch• Notch on superior and inferior surfaces—

vertebral notches: successive vertebralnotches form intervertebral foramina,which permit passage of nerve roots andvessels

• Midline posterior projection from junctionof laminae

• Allows for muscle and ligament attachments

• Project posterolaterally from vertebralarch

• Allow for muscle attachment and articulationwith ribs (thoracic)

• Arise from junction of pedicles and laminae• Possess facet (zygapophysial) joints for

articulation with adjacent processes• Limit undo movement of vertebral column

and maintain vertebral alignment

Superior surfaces possess uncinate process• Bifid• C7, long—vertebra prominensPossess transverse foramina for passage ofvertebral vessels and sympathetic fibers

Long, inferiorly directed

Possess facets for articulation with head andtubercle of ribs

Massive for weight bearing

Short and stout

• 5 sacral vertebrae fuse to form sacrum• Remnants of characteristics typical to

vertebrae are still identifiable

Remnant of taillike caudal eminence

Lamina

Pedicle

Spinousprocess

Transverseprocesses (2)

Superiorarticularprocesses (2)

Inferiorarticularprocesses (2)

Body

Spinousprocess

Transverseprocess

Spinousprocess

Transverseprocess

Body

Spinousprocess

Fused

Fused

Vertebrae Characteristic Significance

Identifying Regional CharacteristicsCervical

Thoracic

Lumbar

Sacral

Coccygeal

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Additional ConceptVertebral (Spinal) CanalAdjacent vertebral foramina form the vertebral canal—contain the spinal cord, meninges, nerve roots, vascular ele-ments (internal venous plexus), and fat.

Clinical ConceptSpina BifidaFailure of the vertebral arches to form correctly results inspina bifida; spina bifida occulta (a mild form) is oftenasymptomatic. More serious forms may result in herniationof meninges—meningocele or meninges and neural tissuethrough the deficiency.

Vertebral ArteryThe long, tortuous course of the vertebral artery throughthe transverse cervical foramina may increase risk of insultbecause of stretch from rotation of the head, resulting inreduced blood flow to the brain, possibly causing dizzinessand light-headedness.


Spinous process

Dura materArachnoid

Pia mater

Superiorarticular

facet

Internal vertebral venous plexusLamina

Posterior rootof spinal nerve

Spinal cord

Anterior root ofspinal nerve

Posteriorlongitudinalligament

Intervertebral cartilage (disk)Nucleus pulposus

Anulusfibrosus

Vertebralveins

Vertebralartery

PedicleVertebral body

Anterior longitudinal ligament

Rootsheath

Spinal ganglion

FIGURE 4-2. Typical vertebra, superior aspect. (Asset provided by




Joints of the back(Figure 4-2)

Joint Type Articulation StructureAtlanto-occipital

Atlantoaxial—2 lateral and 1 median

Intervertebral

Uncovertebral

Zygapophysial (facet)

Synovial

Lateral—synovial;median—pivot

Cartilagi-nous

Synovial

C1 vertebrawith occipitalbone

C1 with C2vertebrae

Surfaces ofadjacentvertebraeconnected byintervertebraldiscs

Adjacentcervicalvertebrae

Betweensuperior andinferiorarticulatingprocesses ofadjacentvertebrae

• Strengthened by anterior andposterior atlanto-occipitalmembranes

• Strengthened and maintainedby the cruciform ligament—formed by longitudinalbands and the transverseligament of the atlas

• Alar ligaments—preventexcessive rotation

• The tectorial membrane—continuation of posteriorlongitudinal ligament, coversthe alar and transverseligaments

• Intervertebral discs providestrong attachment betweenadjacent vertebral bodies—consist of outerfibrocartilaginous anulusfibrosis (attaches to epiphysialrim) and central compressiblenucleus pulposus

• Anterior and posteriorlongitudinal ligamentsstrengthen, provide stability,and limit extension and flexionof the vertebral column,respectively

Uncinate process on superiorsurface of cervical vertebralbodies with inferior surface ofvertebral body superior to it

• Strengthened by accessoryligaments

• Allow for gliding movements

Additional ConceptMultiple accessory ligaments help to strengthen and supportthe joints of the vertebral column:


■ ligamentum flavum—connects adjacent vertebral arches■ supraspinous—connects adjacent spinous processes■ interspinous—connects adjacent spinous processes■ ligamentum nuchae—connects external occipital protu-

berance and cervical spinous processes■ intertransverse ligaments—connects adjacent trans-

verse processes

Clinical SignificanceSlipped DiscHerniation of the nucleus pulposus into or through the anu-lus fibrosis is a common cause of lower back pain and isoften called a slipped or ruptured disk.

SPINAL CORD


Feature Description SignificanceCervical enlargement

Lumbar enlargement

Medullary cone

Cauda equina

Spinal nerves (31 pairs)

Enlarged portion of spinalcord from C4–T1

Enlarged portion of spinalcord from L1–S3

Tapering end of the spinalcord

Formed from anterior andposterior roots that arisefrom the lumbarenlargement andmedullary cone

• 8 cervical, 12 thoracic, 5lumbar, 5 sacral, 1coccygeal

Gives rise to the anterior ramithat form the brachialplexus—innervates upper limbs

Gives rise to the anterior ramithat form the lumbosacralplexus—innervates lower limbs

• Located at L1–L2 vertebrallevel

• Nerve roots contribute tocauda equina

Located in the lumbar cistern—continuation of subarachnoidspace in the dural sac caudal tothe medullary cone

• Formed of anterior andposterior roots from thespinal cord segments

Structure of the spinal cord(Figure 4-2)

The spinal cord is continuous superiorly with the medulla atthe foramen magnum and ends inferiorly at the L1–L2 ver-tebral level. The spinal cord serves as a reflex center andconduction pathway, connecting the brain to the periphery.It is located within the vertebral canal and gives rise to 31pairs of spinal nerves.

(continued)




Roots—anterior and posterior

Spinal ganglion

Gray matter

White matter

Rami—anterior and posterior

• Each contains somaticafferent and efferentfibers and betweenT1–L2 containpresynaptic sympatheticfibers, between S2–S4contain presynapticparasympathetic fibers

• Anterior—efferent• Posterior—afferent• Join to form spinal nerves

Located along posterior root

Located on the inside ofthe spinal cord, deep tothe white matter

Located on the outside ofthe spinal cord, superficialto the gray matter

Terminal branches ofspinal nerves

• Terminate by dividing intoanterior and posterior primaryrami

• Anterior roots contain fibersof somatic and visceral motorneurons

• Posterior roots contain somaticand visceral afferent fibers

Contains primary afferent cellbodies of the somatic andvisceral sensory systems

Divided into posterior, lateral(visceral motor, between T1–L2),and anterior (somatic motor) horns

• Divided into anterior, lateral,and posterior funiculi

• Contains ascending (afferent)and descending (efferent)fiber tracts

• Anterior—supply innervationto majority of body, oftenform plexuses

• Posterior—supply segmentalinnervation to the back

Structure of the spinal cord (continued)

Artery Origin DescriptionAnterior spinal

Posterior spinal (2)

Segmental

Vessels of the spinal cord(Figure 4-2)

Vertebral

Either vertebral orposterior inferiorcerebellar

Ascending cervical,deep cervical,vertebral, posteriorintercostal and lumbar

Supplies anterior 2/3 of spinalcord superiorly

Supplies posterior 1/3 of spinalcord superiorly

• Enter vertebral canal throughintervertebral foramina

• Supply spinal cord andcoverings segmentally

• Anastomose with spinal arteries

(continued)



Vessels of the spinal cord (continued)

Segmental

TerminationDrained by medullaryand radicular veins

Drain into internalvertebral venous plexus

Drain into duralsinuses of cranialvault

Supply nerve roots andassociated meninges

• Variable, but prevalent in theregion of the cervical andlumbosacral enlargements

• Supplement spinal arterial supply

Description• Generally parallel arterial supply• Eventually drain into the

internal vertebral venous plexus

• Communicates with externalvenous plexus on externalaspect of vertebrae

• Potential route for infectionspread from cranial vault

Structure of spinal cord meninges(Figure 4-2)

The spinal cord meninges support and protect the nerveroots and form the subarachnoid space. From superficial todeep:

■ dura mater■ arachnoid mater■ pia mater

Artery Origin DescriptionRadicular—anterior and posterior

Medullary

VeinAnterior spinal (3)

Posterior spinal (3)

Medullary

Radicular

Internal vertebralvenous plexus

Structure Description SignificanceDura mater

Epidural space

Dural root sheaths

• Outer layer of meninges• Continuous with meningeal

layer of cranial durasuperiorly

Between vertebrae and duramater

Extensions of the dural sacthat cover spinal nerve rootsand spinal nerves

• Tough, fibrous layer• Separated from

vertebrae by epiduralspace

Contains fat and the internalvertebral venous plexus

• Sheaths end by blendingwith the epineurium ofthe spinal nerves

• Extend throughintervertebral foramina

(continued)



Structure Description SignificanceDural sac

Subdural space

Arachnoid mater

Subarachnoid space

Arachnoid trabeculae

Lumbar cistern

Pia mater

Denticulate ligaments

Filum terminale—internus and externus

Long tubular sac thatcontains the spinal cord andcerebrospinal fluid

• Potential space, betweenthe dura and arachnoidmater

• Filled with a looselyadhered cell layer

• Middle meningeal layer• Encloses the subarachnoid

space

Between arachnoid materand pia mater

Connective tissue strandsthat connect the arachnoidand pia mater

Inferior prolongation of thesubarachnoid space

• Delicate inner (deep)meninge in contact withthe spinal cord

• Deep to the subarachnoidspace

• 21 pairs• Lateral extensions of pia

mater between the anteriorand posterior roots

• Inferior extension of piamater

• Extends from medullarycone to inferior aspect ofdural sac (interna) and tothe tip of the coccyx(externa)

Begins at the foramenmagnum, anchored tococcyx by filum terminale

Site of subdural hematomawhen trauma causesbleeding into space

Lines dural sac and duralroot sheaths

• Contains cerebrospinalfluid, arachnoidtrabeculae, and bloodvessels

• Inferior prolongationforms the lumbar cistern

Span the subarachnoidspace

Contains the caudaequina and filumterminale internus

Invests spinal bloodvessels and the roots ofthe spinal nerves

Anchors spinal cord to thedura mater

Anchors inferior end ofspinal cord to dura materand coccyx

Structure of spinal cord meninges (continued)

Clinical SignificanceAnesthesiaEpidural anesthesia entails injection of a local anestheticaround the sacral spinal nerves, external to the dural sac.


Spinal Tap and BlockA lumbar puncture (spinal tap) is performed for extractionof cerebrospinal fluid from the lumbar cistern for examina-tion. A spinal block entails introduction of an anestheticinto the cerebrospinal fluid through a lumbar puncture.

MUSCULATURE


Muscles of the backThe muscles located on the back are divided into extrinsic andintrinsic. The extrinsic muscles of the back are discussedwith the upper limb (superficial layer) and thorax (intermedi-ate layer), with which they are associated functionally.

Nuchalligamentand C7–T4vertebrae

Arise asfusedmusclemass fromiliac crestand sacrum,sacroiliacligaments,and spinousprocessesof sacraland lumbarvertebrae

• Capitis—mastoidprocessandsuperiornuchalline

• Cervicis—transverseprocessesof C1–C4vertebrae

Angles of lower ribs andtransverseprocesses ofthoracic andcervicalvertebrae

Angles ofribs andtransverseprocesses ofthoracic and

Segmentalinnervationby posteriorrami ofspinalnerves


• Laterally flexneck androtate head

• Extend headand neckwhencontractingbilaterally

Laterally flexvertebralcolumn; extendvertebralcolumn (chiefextensor ofcolumn) andhead, controlflexion bygradualrelaxation offibers whenactingbilaterally

Intrinsic Back Proximal Distal Main Muscle Attachment Attachment Innervation ActionsSuperficial Layer

Splenius—capitis andcervicis

Intermediate Layer (Erector Spinae)

Iliocostalis—lumborum, thoracis, and cervicis

Longissimus—thoracis, cervicis and capitis

(continued)



Muscles of the back (continued)

TransverseprocessesC4–T12

Posteriorsacrum,posterioriliac spine,transverseprocessesT1–T3 andarticularprocessesof C4–C7

Transverseprocesses

Spinousprocesses

cervicalvertebraeand mastoidprocess

Spinousprocesses ofupperthoracicvertebraeand cranium

Spinousprocesses of 4–6vertebraesuperior andoccipitalbone

Spinousprocesses of 2–4vertebraesuperior

Junction oflamina andtransverseprocess orspinousprocesses of1 (brevis), 2(longus)vertebraesuperior

Spinousprocesses of


• Extendsthoracic andcervicalregions ofvertebralcolumn andhead

• Rotatesvertebralcolumn

Stabilizesvertebrae

Extension androtation of

Intrinsic Back Proximal Distal Main Muscle Attachment Attachment Innervation Actions

Spinalis—thoracis, cervicis, and capitis

Deep Layer (Transversospinal Group)Semispinalis—thoracis, cervicis and capitis

Multifidus

Rotators—brevis and longus

Interspinales

(continued)



Muscles of the back (continued)

Intrinsic Back Proximal Distal Main Muscle Attachment Attachment Innervation Actions

Intertrans-versarii

Levator costarum

of cervicaland lumbarvertebrae

Transverseprocessesof cervicaland lumbarvertebrae

Transverseprocessesof C7–T11vertebrae

vertebraeimmediatelysuperior

Transverseprocesses ofadjacentvertebrae

Adjacent ribbetweentubercle andangle

vertebralcolumn

Lateral flexion andstabilization ofvertebralcolumn

Elevate ribs,assist inlateral flexionof vertebralcolumn

Additional ConceptThe muscles of the back may be divided into 3 layers:superficial—associated with the upper limb; intermedi-ate—associated with the thorax; and deep—associatedwith movement of the vertebral column. They are alsoknown as the intrinsic muscles of the back or true backmuscles.

MnemonicErector Spinae MusclesFrom lateral to medial:

I Like Spaghetti IliocostalisLongissimusSpinalis

Suboccipital Region Structure SignificanceBorders • Roof—semispinalis capitis

• Floor—atlanto-occipitalmembrane and arch of C1

• Identifiablemusculartriangle in the

Suboccipital triangleThe suboccipital triangle is a muscular triangle inferior to theoccipital region of the head; it contains the vertebral artery,posterior arch of the atlas, and the suboccipital nerve (C1).

(continued)



• Superomedial—rectus capitisposterior major

• Superolateral—superioroblique

• Inferolateral—inferior oblique

• Proximal attachment: C2spinous process

• Distal attachment: inferiornuchal line of occipital bone

• Proximal attachment: C1posterior arch

• Distal attachment: inferiornuchal line of occipital bone

• Proximal attachment: C2spinous process

• Distal attachment: C1transverse process

• Proximal attachment: C1transverse process

• Distal attachment: occipitalbone

suboccipitalregion

• Actions:extend androtate head

• Innervation:suboccipitalnerve (C1)

Suboccipital triangle (continued)

Suboccipital Region Structure Significance

MusclesRectus capitis posterior major

Rectus capitis posterior minor

Inferior oblique of the head

Superior oblique of the head


The pelvic (anterior) aspect of the bones of the gluteal region aredescribed in Chapters 3 and 4.

INTRODUCTIONThe lower limb is divided for descriptive purposes by skele-tal elements into:

■ gluteal region—portion between thigh and trunk posteriorlythat includes the pelvic girdle: ilium, ischium, and pubis

■ thigh—portion between the gluteal region posteriorly andthe knee that includes the femur

■ leg—portion between the knee and ankle that includes thetibia and fibula

■ foot—portion distal to the ankle that includes themetatarsals and phalanges; the tarsal bones form the ankle

GLUTEAL REGION

5 Lower Limb

126

Bones of the gluteal region(Figure 5-1)

Bone Feature SignificanceSacrum Median crest Fused spinal processes of sacral vertebrae

Posterior sacral Transmit posterior rami of first 4 sacral foramina nerves

Sacral hiatus Inferior opening of the vertebral canal between the sacral cornu (horns)

Coccyx Apex of the coccyx • Directed inferiorly• Coccyx is formed by the fusion of the

4 inferiormost vertebrae

Hip Bone (Pelvic Bone, Coxal Bone)—Fusion of the 3 Bones BelowIlium Body of ilium Contributes to the acetabulum

Wing (ala) of ilium • Concave surface• Marked by the anterior, posterior, and

inferior gluteal lines

(continued)


CHAPTER 5 | LOWER LIMB 127


Bones of the gluteal region (continued)

Iliac crest • Bony ridge between the anterior superior, and posterior superior iliac spines

• Attachment for fascia lata, tensor of fascia lata, external oblique, internal oblique, transverse abdominal, latissimus dorsi, quadratus lumborum, erector spinae, and iliacus

Posterior superior Attachment for sacroiliac ligaments and iliac spine multifidus

Posterior inferior Part of auricular surface of iliumiliac spine

Anterior gluteal • Gluteus medius attaches between anterior line and posterior gluteal lines

• Gluteus minimus attaches between anterior and inferior gluteal lines

Posterior gluteal • Gluteus maximus attaches posterior to the line posterior gluteal line

• Gluteus medius attaches between anterior and posterior gluteal lines

Inferior gluteal line Gluteus minimus attaches between anterior and inferior gluteal lines

Greater sciatic • Notch converted into greater sciatic fora-notch/foramen men by the sacrospinous ligament

• Major passageway for structures exiting the pelvis and entering the gluteal region—including: piriformis, superior and inferior gluteal vessels and nerves, sciatic and posterior femoral cutaneous nerves, internal pudendal vessels, pudendal nerve and nerves to obturator internus, and quadratus femoris

Ischium Ischial spine Attachment for superior gemellus and sacrospinous ligament

Ischial tuberosity Attachment for hamstring portion of adductor magnus, hamstrings, and sacrotuberous ligament

Body Contributes to the acetabulum

Lesser sciatic • Notch converted into lesser sciatic foramennotch/foramen by the sacrospinous and sacrotuberous

ligaments• Passageway for structures exiting and

entering the perineum—tendon of obturatorinternus (exiting), internal pudendal vessels,and pudendal nerve (entering)

Pubis Body Contributes to the acetabulum

LWBK096-3880G-C05_126-157.qxd 6/25/08 10:23 AM Page 127 Aptara (PPG-Quark)

Quadricepsfemoris tendon

Fibularcollateralligament

Patellarligament

Interosseousmembrane

Talus

Medialcuneiform

Ilium

S1

Anterior superioriliac spine

Sacrum

Anterior inferioriliac spine

Pubis

Head of femur

Greatertrochanter

Neck of femur

Femur

Medial femoralcondylePatella

Lateral epicondyle

Lateral femoralcondyleTibial condyle

Head of fibula

Tibial tuberosity

Ischium

Lessertrochanter

Pubicsymphysis

Tibialcollateralligament

Medialtibial

condyle

Medialepicondyle

Tibia

Fibula

Medial malleolus

Lateral malleolus

FIGURE 5-1. Lower limb bones. Anterior view. (Asset provided by


128



Additional ConceptAcetabulumThe acetabulum is formed by the bodies of the pubis,ischium, and ilium; it forms the socket of the hip joint.

Clinical SignificanceContusion of the iliac crest is known as a “hip pointer.”

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsGluteus Ilium posterior Iliotibial tract Inferior • Extends and maximus to posterior and gluteal gluteal laterally

gluteal line, tuberosity rotates thighsacrum, coccyx; • Steadies and sacrotuber- thighous ligament

Gluteus Ilium between Greater tro- Superior • Abducts and medius anterior and chanter of gluteal medially

posterior gluteal femur rotates thighlines • Levels pelvis

Gluteus Ilium between when contral-

minimus anterior and ateral leg is

inferior gluteal unsupported

lines

Tensor of Anterior superior Lateral con-fascia lata iliac spine dyle of tibia

via iliotibial tract

Piriformis Sacrum and Greater Sacral plexus • Laterally sacrotuberous trochanter of (S1 and S2) rotates thighligament femur • Assist in

Obturator Margins of Nerve to holding head

internus obturator fora- obturator of femur in

men and obtura- internus acetabulum

tor membrane

Superior Ischial spinegemellus

Inferior Ischial Nerve to gemellus tuberosity quadratus

Quadratus Intertrochan- femoris

femoris teric crest

Muscles of the gluteal region

Clinical SignificanceThe gluteal region is a common site for intramuscular injec-tion; injections are made in the superolateral quadrant toavoid neurovascular elements.


MnemonicLateral Rotators of the Hip Joint

Play Golf Or Go On QuaaludesPiriformisGemellus superiorObturator internusGemellus inferiorObturator externusQuadratus femoris


Nerves of the gluteal region

Nerve Origin Structures InnervatedSuperior gluteal Sacral plexus Gluteus medius, gluteus minimus,

tensor of fascia lata

Inferior gluteal Gluteus maximus

Pudendal Supplies the perineum; supplies no structures in the gluteal region

Sciatic Supplies the lower limb; supplies no structures in the gluteal region

Nerve to quadratus Quadratus femoris and inferior femoris gemellus

Nerve to obturator Obturator internus and superior internus gemellus

Posterior femoral Skin of gluteal regioncutaneous

Superior clunial L1–L3

Middle clunial S1–S3

Inferior clunial S2–S3

Iliohypogastric Lumbar plexus Skin of buttock

Artery Origin DescriptionSuperior Internal Supplies gluteus maximus, gluteus medius, gluteal iliac gluteus minimus, and tensor of fascia lata

Inferior • Supplies gluteus maximus, obturator internus, gluteal and quadratus femoris

• Participates in cruciate anastomosis with the deep femoral (1st perforating branch) and the medial and lateral circumflex arteries

Internal • Supplies structures in the perineal regionpudendal • Supplies no structures in the gluteal region

Vessels of the gluteal region(Figure 5-2)


131

Dorsal metatarsalarteries

Deep plantar artery

Medial tarsal arteries

Dorsalis pedis artery

Anterior medialmalleolar artery

Descendinggenicular artery

Superior medialgenicular artery

Inferior medialgenicular artery

Posteriortibial artery

Interosseousmembrane

Femoral artery

Medial circumflexfemoral artery

Anterior andposterior branchof obturatorartery

Obturator artery

Superficial externalpudendal artery

Internal iliacartery (cut)

Common iliac artery

Aorta

Dorsal digital arteries

Arcuate artery

Lateral tarsal artery

Anterior lateralmalleolar artery

Perforating branchof fibular artery

Anterior tibial artery

Anterior tibialrecurrent artery

Inferior lateralgenicular artery

Superior lateralgenicular artery

Perforatingarteries

Lateral circumflexfemoral artery:

Ascending branchTransverse branch

Descending branch


Inferior epigastricartery

Superficial epigastricartery

Deep circumflexiliac artery

Superficial circumflexiliac artery

Deep femoral artery

FIGURE 5-2. Arteries of lower limb, anterior view. (From Tank

PW, Gest TR. LWW Atlas of Anatomy. Baltimore: Lippincott



Additional ConceptVenous DrainageThe venous drainage generally parallels arterial supply.

THIGH REGION


Bone Feature SignificanceFemur Head • Articulates with acetabulum(thigh • Bears a fovea for attachment of the bone) ligament of the head of the femur

Neck Attachment for the capsule of the hip joint

Greater trochanter Attachment for gluteus medius and minimus,piriformis, obturator internus, superior and inferior gemelli, and vastus lateralis

Lesser trochanter Attachment for iliacus and psoas major

Trochanteric fossa Attachment for obturator externus

Intertrochanteric Attachment for iliofemoral ligament and line vastus medialis

Intertrochanteric Attachment for quadratus femoriscrest

Linea aspera Attachment for pectineus, iliacus, vastus medialis and lateralis, adductor magnus, longus and brevis, biceps femoris (short head), and gluteus maximus

Gluteal tuberosity Attachment for gluteus maximus

Adductor tubercle • Associated with the medial epicondyle• Attachment for adductor magnus

Shaft Attachment for vastus intermedius

Medial condyle Articulate with tibial plateau

Lateral condyle

Intercondylar fossa • Depression between medial and lateral condyles

• Attachment for anterior and posterior cruciate ligaments

Medial epicondyle • Attachment for tibial collateral ligament, gastrocnemius

• Bears adductor tubercle

Lateral epicondyle Attachment for fibular collateral ligament, gastrocnemius, plantaris, and popliteus

Bones of the thigh(Figures 5-1 and 5-2)


Clinical Significance

Coxa Vara and Coxa ValgaWhen the angle of inclination between the neck and shaft ofthe femur is decreased, the condition is coxa vara; when it isincreased, it is coxa valga.

Femoral FractureFemoral fractures often occur at the neck; spiral fracturesoccur in the shaft of the femur.


Muscles of the thigh

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsAnterior Compartment—Hip Flexors and Knee ExtensorsPectineus Pubis Pectineal line Femoral or Adducts, flexes,

of femur obturator and medially rotates thigh

Psoas T12 and lumbar Lesser troch- Segmental Flexes thigh major vertebrae anter of femur (L1–L3) and stabilizes

hip joint

Psoas T12–L1 Pectineal line Segmentalminor

Iliacus Iliac fossa Lesser troch- Femoralanter of femur

Sartorius Anterior super- Medial con- Flexes, abducts ior iliac spine dyle of tibia and laterally

via pes rotates thigh, anserinus flexes leg

Rectus Anterior inferior Tibial tubero- Extends leg,femoris iliac spine sity via patel- flexes thigh,

lar ligament and stabilizes hip joint

Vastus Greater tro- Extends leglateralis chanter and

linea aspera of femur

Vastus Intertrochantericmedialis line and linea

aspera of femur

Vastus Femoral shaftintermedius

(continued)



Muscles of the thigh (continued)

Medial Compartment—Thigh AdductorsAdductor Pubis Linea aspera Obturator Adducts thighlongus of femur

Adductor brevis

Adductor • Adductor • Adductor • Adductor • Adductor magnus portion: pubis portion: glu- portion: portion:

• Hamstring teal tubero- obturator adducts thighportion: ischial sity and • Hamstring • Hamstring tuberosity linea aspera portion: portion:

• Hamstring tibial divi- extends thighportion: sion of adductor sciatictubercle of femur

Gracilis Pubis Medial con- Obturator Adducts thigh,dyle of tibia flexes and via pes mediallyanserinus rotates leg

Obturator Margins of obtu- Trochanteric • Laterally externus rator foramen fossa of rotates thigh

and obturator femur • Holds head of membrane— femur in externally acetabulum

Posterior Compartment—Knee Flexors and Hip Extensors

Semiten- Ischial Medial con- Tibial division Extend thigh, dinosus tuberosity dyle of tibia of sciatic flex and

via pes ans- medially rotate erinus leg

Semimem- Medial con-branosus dyle of

tibia

Biceps • Long head: Head of fibula • Long head: Flexes and femoris ischial tubero- tibial divi- laterally rotates

sity sion of leg, flexes thigh• Short head: sciatic

linea aspera • Short head: common fibular divi-sion of sciatic

Proximal DistalMuscle Attachment Attachment Innervation Main Actions


Additional ConceptQuadriceps FemorisThe rectus femoris, vastus lateralis, vastus medialis, and vas-tus intermedius are collectively referred to as the quadri-ceps femoris.HamstringsThe semitendinosus, semimembranosus, and biceps femorisare collectively referred to as the hamstrings.

Clinical SignificanceCrampA cramp or spasm in the anterior thigh muscles—a “CharleyHorse”—usually involves the rectus femoris.

GracilisGracilis is sometimes transplanted to replace damaged mus-cles elsewhere in the body.

Groin pullA groin pull usually refers to straining the proximal aspectof the musculature of the medial compartment of the thigh.

Mnemonics

Adductor MagnusAM SO: Adductor Magnus innervated by Sciatic and

Obturator.

Pes AnserinusPes Anserinus—Say Grace before Serving Tea

SartoriusGracilisSemitendinosus


Nerves of the thigh

Nerve Origin Structures InnervatedFemoral Lumbar plexus • Pectineus, sartorius, iliacus, rectus

femoris, vastus lateralis, medialis, and intermedius

• Sensory to skin over anteromedial thigh

Obturator Adductor longus, adductor brevis, gracilis, pectineus, obturator externus, and adductor magnus

(continued)



Nerves of the thigh (continued)


Tibial division of Sciatic Long head of biceps femoris, sciatic semitendinosus, semimembranosus

Common fibular Short head of biceps femorisdivision of sciatic

Genitofemoral Lumbar plexus Sensory to skin of inguinal region

Lateral femoral Sensory to skin over lateral thighcutaneous

Posterior femoral Sacral plexus Sensory to skin of gluteal region and cutaneous posterior thigh

Vessels of the thigh(Figure 5-2)


Internal Internal Supplies external genitals and perineal regionpudendal iliac

Obturator • Divides into anterior and posterior branches• The posterior branch gives rise to the

acetabular branch and the artery to the head of the femur

• Both branches supply the adductor compartment of the thigh

Femoral Continua- • Gives rise to deep femoral, superficial epigastric,tion of ex- superficial circumflex iliac, external pudendal, ternal iliac medial and lateral femoral circumflex, and

descending genicular• Terminates by becoming the popliteal artery

after passing through the adductor hiatus

Deep Femoral • Gives rise to 4 perforating branches that supply femoral adductor magnus and hamstrings

• 1st perforating branch participates in cruciate anastomosis with the inferior gluteal and the medial and lateral circumflex arteries

Superficial Supplies subcutaneous tissues—lymph nodes, epigastric skin, and fascia over the abdominal wall

Superficial Supplies subcutaneous tissues—lymph nodes, circumflex skin, and fascia over the inguinal regioniliac

(continued)


Additional ConceptVenous DrainageVenous drainage generally follows arterial supply.

Clinical SignificanceFemoral ArteryThe proximal portion of the femoral artery is easily accessible and easily damaged because of its superficiallocation.



Vessels of the thigh (continued)

Superficial Supplies subcutaneous tissues—skin and fascia external over the external genitalspudendal

Deep external pudendal

Medial Deep • Supplies most of the blood to the head and femoral femoral neck of femurcircumflex • Participates in cruciate anastomosis with the

inferior gluteal, lateral circumflex, and 1st per-forating branch of the deep femoral

Lateral • Supplies neck of femur and contributes to femoral anastomosis around knee jointcircumflex • Participates in cruciate anastomosis with the

inferior gluteal, medial circumflex, and 1st per-forating branch of the deep femoral

Descending Femoral Supplies subcutaneous tissue on medial aspect genicular of knee and contributes to anastomosis around

knee

LEG REGIONLeg bones(Figures 5-1, 5-4, and 5-5)

Bone Feature SignificanceTibia Medial condyle • Articulates with femoral condyles

• Attachment for semimembranosus and tibial collateral ligament

(continued)



Clinical SignificanceFracturesTibiaThe most common site for a fracture of the tibia is alongthe shaft at the junction of its middle and inferior thirds;it is the narrowest part and has a relatively poor bloodsupply.

Bone Feature Significance

Lateral condyle • Articulates with femoral condyles• Attachment for iliotibial band

Anterior intercon- • Located between the condylesdylar area • Provide attachment sites for anterior and

Posterior intercon- posterior cruciate ligaments and the menisci

dylar area

Tuberosity of the Attachment for patellar ligamenttibia

Shaft Attachment for tibial collateral ligament, popliteus, soleus, flexor digitorum longus, interosseous membrane, gracilis, and semitendinosus

Soleal line Attachment for popliteus, soleus, flexor digitorum longus, and tibialis posterior

Medial malleolus • Attachment for deltoid ligament• Lateral surface articulates with the

talus

Fibula Head Attachment for biceps femoris, fibular collateral ligament, fibularis longus, extensor digitorum longus, and soleus

Neck Common fibular nerve wraps around neck to access the anterior aspect of the leg

Shaft Attachment for interosseous membrane, extensor digitorum longus, extensor hallucis longus, soleus, tibialis posterior, fibularis longus, brevis, and tertius

Lateral malleolus • Medial surface articulates with the talus• Attachment for the posterior and anterior

talofibular ligaments and the calcaneo-fibular ligament

Leg bones (continued)



FibulaFracture of the fibula often occurs proximal to the lateralmalleolus and is often associated with fracture dislocationsof the ankle joint.

Muscles of the leg

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsAnterior Compartment

Tibialis Tibia and inter- 1st metatarsal Deep fibular Dorsiflexes anterior osseous mem- ankle, inverts

brane foot

Extensor Middle and Extends digits digitorum distal phalan- 2–5, dorsiflexes longus ges digits 2–5 ankle

Extensor Fibula and inter- Distal Extends digit 1, hallucis osseous mem- phalanx dorsiflexes longus brane digit 1 ankle

Fibularis 5th metatarsal Dorsiflexes tertius ankle, everts

foot

Lateral Compartment

Fibularis Fibula 1st metatarsal Superficial Plantarflex longus fibular ankle, evert

Fibularis Tuberosity of foot

brevis 5th metatarsal

Posterior Compartment

Gastroc- Femoral Calcaneus via Tibial Flexes leg, nemius condyles calcaneal plantarflexes

tendon ankle

Soleus Soleal line of Plantarflexes tibia and fibula ankle

Plantaris Oblique Plantarflexes popliteal liga- ankle and ment and lateral provides proprio-supracondylar ceptive informa-ridge of femur tion on tension

of triceps surae

Popliteus Lateral femoral Tibia Flexes and condyle and lat- unlocks kneeeral meniscus

(continued)



Muscles of the leg (continued)

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsTibialis Fibula and Tuberosity of Plantarflexes posterior interosseous navicular ankle, inverts

membrane foot

Flexor Distal phalanx Flexes joints hallucis digit 1 of 1st digit, longus plantarflexes

ankle, and supports longitudinal arches of foot

Flexor Tibia and fibula Distal phal- Plantarflexes digitorum anges digits ankle, flexes longus 2–5 digits 2–5, and

supports longi-tudinal arches of foot

Additional ConceptTriceps SuraeThe gastrocnemius, soleus, and plantaris are collectivelyreferred to as the triceps surae.

Clinical SignificanceCompartment SyndromeCompartment syndrome is increased intracompartmentpressure due to muscle swelling or shin splints. Shin splintsis pain resulting from repetitive microtrauma to the tibialisanterior.

GastrocnemiusGastrocnemius strain is a painful injury resulting from tear-ing the medial belly of the muscle during knee extension anddorsiflexion of the ankle.

MnemonicsEversion versus Inversion

The second letter in the name of the muscle indicates thefunction:

Eversion:perineus longusperineus brevis


perineus tertiusInversion:tibialis anteriortibialis posterior

Plantarflexion

Plantarflexion occurs when you step on a plant with thesole of your foot.


Nerves of the leg

Nerve Origin Structures InnervatedTibial Sciatic Supplies gastrocnemius, soleus, plantaris,

popliteus, flexor hallucis longus, flexor digitorum longus, and tibialis posterior

Common fibular Gives rise to the lateral sural cutaneous and superficial and deep fibular

Superficial fibular Common Supplies fibularis longus and brevis and fibular sensory to anterior aspect of distal leg

Deep fibular Supplies tibialis anterior, extensor hallucis longus, extensor digitorum longus, and fibularis tertius

Posterior femoral Sacral plexus Sensory to skin of calfcutaneous

Saphenous Femoral • Sensory to medial aspect of leg• Runs with great saphenous vein

Lateral sural Common fibular Sensory to posterolateral aspect of legcutaneous

Medial sural Tibial Sensory to posterior aspect of legcutaneous

Superficial fibular Common fibular Sensory to anterolateral aspect of leg

Sural Common fibular Sensory to lateral and posterior aspect and tibial of leg

Artery Origin DescriptionPopliteal Femoral • Begins at the adductor hiatus as a continuation

of the femoral• Gives rise to genicular, anterior, and posterior

tibial arteries

Genicular Popliteal • Composed of superior lateral and medial, inferior lateral, and medial genicular

• Contribute the anastomosis around the knee joint

Vessels of the leg(Figure 5-2)

(continued)



Clinical SignificancePosterior Tibial ArteryThe posterior tibial arterial pulse can be palpated betweenthe medial malleolus and the calcaneal tendon.

FOOT REGION


Artery Origin Supplies/Gives Rise to

Vessels of the leg (continued)

Anterior • Runs with deep fibular nerve on interosseous tibial membrane

• Supplies anterior leg and dorsum of foot, terminates as the dorsalis pedis

Posterior • Gives off fibular arterytibial • Supplies posterior aspect of leg and sole of

foot, terminates as medial and lateral plantar arteries

Fibular Posterior Supplies posterolateral aspects of legtibial

Bone Characteristic SignificanceTalus Trochlea Articulates with tibia and malleoli of tibia

and fibula

Head Articulates with the navicular, forming a ball-and-socket type joint, supported inferiorly by the plantar calcaneonavicular ligament

Cal- Calcaneal Attachment for abductor digiti minimi, caneus tuberosity abductor hallucis, flexor digitorum brevis,

plantar aponeurosis, long plantar ligament, quadratus plantae, and the plantar calcaneo-cuboid ligament

Fibular trochlea Separates grooves for the tendons of fibularis longus and brevis

Bones of the foot(Figures 5-1 and 5-4)

(continued)


Clinical SignificanceAvulsionSudden inversion of the foot may cause avulsion of the tuberos-ity of the 5th metatarsal,, the attachment for fibularis brevis.



Bones of the foot (continued)

Talar shelf Attachment for tibialis posterior, deltoid ligament, and plantar calcaneonavicular ligament; inferior surface grooved for tendon of flexor hallucis longus

Navicular Tuberosity Attachment for tibialis posterior

Cuboid Bears facet for sesamoid bone in tendon of fibularis longus to glide

Medial Articular surfaces Articulates with 4 bones—navicular, cuneiform intermediate cuneiform, and 1st and 2nd

metatarsals

Inter- Articulates with 4 bones—navicular, medial mediate and lateral cuneiforms, and 2nd metatarsalcuneiform

Lateral Articulates with 6 bones—navicular, inter-cuneiform mediate cuneiform, cuboid, and 2nd, 3rd, 4th

metatarsals

Metatar- Base Articulate with tarsal bones and adjacent sals (5) metatarsals

Proximal Heads Articulate with proximal phalangesphalan-ges (5)

Middle Articulate with more distal phalangesphalan-ges (5)

Distal Tuberosity Ungual tuberosity supports the toenailphalan-ges (4)

Muscles of the foot

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsDorsumExtensor Calcaneus Tendons of ex- Deep fibular Extend digits digitorum tensor digit- 2–5brevis orum longus

(continued)



Muscles of the foot (continued)

144

Extensor Proximal Extend digit 1hallucis phalanx of brevis digit 1

Plantar Surface—Layer 1 (Most Superficial)Abductor Calcaneus Proximal pha- Medial Abducts digit 1hallucis lanx of digit 1 plantar

Flexor Middle pha- Flexes middle digitorum langes of phalanges of brevis digits 2–5 digits 2–5

Abductor Proximal pha- Lateral plantar Abducts digit 5digiti lanx of digit 5minimi

Plantar Surface—Layer 2Quadratus Calcaneus Tendons of Lateral plantar Assists with toe plantae flexor digit- flexion

orum longus

Lumbricals Tendons of Extensor • 1st: medial Flex metatarso-flexor digitorum expansions plantar phalangeal longus • 2nd–4th: joints, extend

lateral interphalangeal plantar joints

Plantar Surface—Layer 3Flexor Cuboid and 3rd Proximal Medial Flexes digit 1hallucis cuneiform phalanx of plantarbrevis digit 1

Adductor • Oblique head: Lateral plantar • Adducts hallucis metatarsals digit 1

2–4 • Maintains • Traverse head: transverse

metatarsopha- arch of footlangeal joints

Flexor digiti 5th metatarsal Proximal pha- Flexes digit 5minimi lanx of digit 5brevis

Plantar Surface—Layer 4Plantar in- Metatarsals 3–5 Proximal pha- Lateral plantar • Adductsterossei (3) langes 3–5 digits 2–4

• Flex metatar-sophalangeal joints

Dorsal in- Metatarsals 1–5 Proximal pha- • Abducts terossei (4) langes 2–4 digits 2–4

• Flex metatar-sophalangeal joints


Clinical SignificanceExtensor Digitorum BrevisA hematoma resulting from trauma to the extensor digito-rum brevis produces edema near the ankle that is oftenconfused with an ankle sprain.


Nerves of the foot

Nerve Origin Structures InnervatedSaphenous Femoral • Runs with great saphenous vein

• Sensory to medial aspect of foot

Medial sural Tibial Sensory to lateral aspect of ankle and cutaneous foot

Superficial fibular Common fibular Sensory to dorsum of foot

Deep fibular • Supplies extensor digitorum brevis• Sensory to skin between the 1st and

2nd toes

Calcaneal(s) Tibial and sural Sensory to heel

Medial plantar Tibial • Supplies abductor hallucis, flexor digitorum brevis, flexor hallucis brevis and 1st lumbrical

• Sensory to medial aspect of sole and medial 31⁄2 toes

Lateral plantar • Supplies quadratus planate, abductor digiti minimi, flexor digiti minimi brevis,plantar and dorsal interossei, lateral 3 lumbricals, and adductor hallucis

• Sensory to lateral aspect of sole and lateral 11⁄2 toes

Sural Tibial and Sensory to lateral aspect of footcommon fibular

Vessels of the foot(Figure 5-2)

Artery Origin DescriptionDorsal SurfaceDorsalis Anterior • Continuation of the anterior tibial after it passes pedis tibial into the foot

• Gives rise to the lateral tarsal, arcuate, 1st dorsal metatarsal, and deep plantar

Lateral Dorsalis Anastomosis with arcuatetarsal pedis

Arcuate Gives the 2nd, 3rd, and 4th dorsal metatarsals

(continued)



MISCELLANEOUS


Vessels of the foot (continued)

Feature Structure SignificanceFemoral Triangular region in antero- Location of neurovascular triangle superior aspect of thigh, deep to structures entering and leaving

fascia lata: thigh through subinguinal space,• Superior border (base): inguinal from lateral to medial:

ligament • Femoral nerve• Medial border: adductor longus • Femoral sheath—contains:• Lateral border: sartorius • Femoral artery• Roof: fascia lata—deficiency: • Femoral vein

cribriform fascia and saphenous • Femoral canal (fat and opening, pierced by great deep inguinal lymph nodes)saphenous vein

• Floor: iliopsoas (laterally) and pectineus (medially)

Areas of lower limb(Figure 5-3)

(continued)

Dorsal Arcuate Give off 2 dorsal digitalsmetatarsals

Dorsal Dorsal Supplies the digitsdigitals metatarsals

1st dorsal Dorsalis Supplies the 1st digitmetatarsal pedis

Deep Anastomosis with lateral plantar to form plantar plantar arch

Plantar SurfaceMedial Posterior Divides into superficial and deep branches that plantar tibial supply the digits

Lateral Forms plantar arch with deep plantarplantar

Plantar Plantar Give rise to plantar digitalsmetatarsals arch

Plantar Plantar Supply the digitsdigitals metatarsals

Plantar arch Lateral Gives rise to plantar metatarsalsplantar



MnemonicsBorders of Popliteal FossaThe two “semi” muscles go together—semimembranosusand semitendinosus.

Semi contains an “M”; therefore, they are medial, leav-ing biceps femoris as the lateral border.

Borders of Femoral Triangle

So I May Always Love Sally:Superior: Inguinal ligamentMedial: Adductor longusLateral: Sartorius


Feature Structure Significance

Areas of lower limb (continued)

Adductor • Intermuscular passage found • Also known as subsartorial canal deep to sartorius canal

• Proximal opening—apex of • Transmits femoral artery, femoral triangle, distal femoral vein, and saphenous opening—adductor hiatus nerve

Popliteal Fat-filled, diamond-shaped space Contains:fossa posterior to knee joint; boundaries: • Popliteal artery

• Superolateral: biceps femoris • Popliteal vein—receives • Superomedial: semimembra- small saphenous vein in fossa

nosus • Tibial nerve• Inferolateral: gastrocnemius • Common fibular nerve• Inferomedial: gastrocnemius • Popliteal lymph nodes• Roof: popliteal fascia• Floor: popliteus

Arches of 3 arches formed by bones, • Act as shock absorbers and the foot muscles, tendons, ligaments, springboards during locomo-

and fascia tion and bear weight of 1. Medial longitudinal arch body2. Lateral longitudinal arch • Maintained by passive and 3. Transverse arch dynamic support:

• Passive—bones, connective tissue structures (plantar aponeurosis and long, short and spring ligaments)

• Dynamic—intrinsic musclesof foot and tendons of leg muscles passing into foot


Contents of Femoral Triangle

NAVELfemoral Nervefemoral Arteryfemoral VeinEmpty space, containingLymphatics

Clinical SignificanceFemoral RingThe “empty space” of the mnemonic is the femoral canal;the proximal opening of the femoral canal is the femoralring, a common site for a femoral hernia.


Common iliac arteryand vein (cut)

Adductor longusmuscle

Femoral triangle(outlined)

External iliac arteryand vein (cut)

Internal iliac arteryand vein (cut)

Pectineus muscle

Femoral arteryand vein

Great saphenousvein (cut)

Femoral sheath

Fascia lata (cut)

Sartorius muscle

Iliopsoas muscle

Lateral femoralcutaneous nerve

Inguinal ligament

Anterior superioriliac spine

Femoral nerve

Iliacus muscle

Psoas majormuscle (cut)

FIGURE 5-3. Femoral triangle, anterior view. (From Tank PW,

Gest TR. LWW Atlas of Anatomy. Baltimore: Lippincott Williams &

Wilkins; 2009:104.)



Superficial structures of the lower limb

Structure Course/SignificanceVesselGreat saphenous • Origin: dorsal digital vein of 1st digit and the dorsal vein venous arch

• Runs anterior to medial malleolus, posterior to medial femoral condyle

• Passes through saphenous opening to enter femoral vein

Small saphenous • Origin: dorsal digital vein of 5th digit and the dorsal vein venous arch

• Runs posterior to lateral malleolus superiorly along posterior aspect of the leg

• Pierces the deep fascia to enter the popliteal vein in the popliteal fossa

Dorsal venous Highly variable superficial venous network on dorsum of arch foot

Perforating veins Drain venous blood from superficial veins to deep veins

Lymphatics of Superficial lymphatic vessels accompany veins to enter lower limb superficial lymph nodes, including popliteal, inguinal, and

external iliac groups

Cutaneous NerveSubcostal • Origin: T12

• Lateral cutaneous branch is sensory to skin of hip

Genitofemoral • Origin: lumbar plexus• Sensory to skin of femoral triangle

Iliohypogastric • Origin: lumbar plexus• Lateral cutaneous branch is sensory to skin of supero-

lateral gluteal region

Ilioinguinal • Origin: lumbar plexus• Femoral branch is sensory to skin of femoral triangle

Lateral cutan- • Origin: lumbar plexuseous nerve of • Sensory to skin of lateral and anterior thighthigh

Obturator Cutaneous branch sensory to skin of medial aspect of thigh

Femoral Cutaneous branch sensory to skin of anterior and medial thigh

Saphenous • Origin: femoral• Sensory to skin of medial aspect of leg• Runs with great saphenous vein

Lateral sural • Origin: common fibularcutaneous • Sensory to skin of posterolateral leg

Medial sural • Origin: tibialcutaneous • Sensory to skin of posterior leg and lateral ankle and foot

Sural • Origin: tibial and common fibular• Sensory to skin of posterolateral leg

(continued)



Structure Course/Significance

Superficial structures of the lower limb (continued)

Superficial • Origin: common fibularfibular • Sensory to skin of anterolateral leg and dorsal aspect

of foot

Deep fibular • Origin: common fibular• Sensory to skin between the 1st and 2nd digit on the

dorsum of the foot

Clunials • Superior, middle, and inferior• Origin: lumbar and sacral plexuses and branches of the

posterior cutaneous nerve of the thigh• Sensory to skin of gluteal region

Posterior • Origin: sacral plexuscutaneous nerve • Sensory to skin of posterior aspect of thighof thigh

Lateral plantar • Origin: tibial• Sensory to skin of lateral aspect of sole of foot

Medial plantar • Origin: tibial• Sensory to skin of medial aspect of sole of foot

Tibial Calcaneal branches are sensory to skin over calcaneus

Fascia/Connective Tissue Significance/StructureFascia lata Deep fascia of the thigh

Iliotibial tract • Thickening of fascia lata over lateral aspect of thigh• Extends from iliac tubercle to lateral condyle of tibia• Attachment for tensor fascia lata and gluteus maximus

Fascia of lower limb

Clinical SignificanceNerve BlockThe ilioinguinal and iliohypogastric nerves can be blockedby injecting anesthetic near the anterior superior iliac spine;the femoral can be blocked near the midpoint of the inguinalligament.

Great Saphenous VeinThe great saphenous vein and its tributaries may becomevaricose, mainly from incompetent valves. During saphe-nous cutdown, an incision is made anterior to the medialmalleolus to locate the great saphenous vein for infusion oftherapeutic agents.

(continued)


Additional ConceptFourth CompartmentDistally, a fourth compartment—the interosseous compart-ment of the foot exists.


Fascia/Connective Tissue Significance/Structure

Fascia of lower limb (continued)

Saphenous opening • Hiatus in the fascia lata inferior to the medial aspect of inguinal ligament

• Falciform margin (lateral and inferior) is sharp• Covered by cribriform fascia• Great saphenous vein passes through to enter

femoral vein

Falciform margin Sharp inferior and lateral borders of saphenous opening

Cribriform fascia Membranous layer of subcutaneous tissue that covers the saphenous opening

Crural fascia Deep fascia of the leg

Extensor retinacula Thickened crural fascia over distal leg

Femoral sheath • Extension of transversalis fascia through subinguinal space into the femoral triangle

• Divided into 3 compartments that transmit femoral artery, vein, and femoral canal between the abdominopelvic cavity and femoral triangle of the thigh

Femoral canal • Medial-most of the 3 compartments of the femoral sheath

• Contains fat and lymphatics• Allows for expansion of femoral vein during

increased venous return

Popliteal fascia Deep fascia forming roof of popliteal fossa

Plantar fascia • Deep fascia of sole of foot• Thickened central aspect forms plantar aponeurosis• Protects sole of foot and supports arches

Plantar aponeurosis • Thickened central region of plantar fascia• Reinforced distally by superficial transverse

metatarsal ligament• Vertical septa extend superiorly from aponeurosis to

divide foot into 3 compartments:1. Medial2. Central3. Lateral


Clinical SignificanceCompartment SyndromeIncreased pressure in the fascial compartments of the lowerlimb produces compartment syndromes, causing pain andtissue damage.

Plantar FasciitisInflammation of the plantar aponeurosis—plantar fasciitis,results from high-impact exercise and causes pain over theheel and medial aspects of the foot.


Lumbosacral plexus

Nerve Significance/StructureRoots L1–S4 spinal nerves’ anterior rami form plexus

Divisions Rami terminate by dividing into an anterior and posterior divisions

Branches (6): 1. Femoral nerve (L2–L4)1. Femoral nerve 2. Obturator nerve (L2–L4)2. Obturator nerve 3. Common fibular nerve (L4–S2; terminates by 3. Common fibular nerve dividing into superficial and deep fibular nerves)4. Tibial nerve 4. Tibial nerve (L4–S3)5. Superior gluteal nerve • 1–4 above innervate the lower limb6. Inferior gluteal nerve 5. Superior gluteal nerve (L4–S1)

6. Inferior gluteal nerve (L5–S2) • 5–6 above innervate the gluteal region• The common fibular and tibial nerves comprise

the sciatic nerve

Clinical SignificanceFemoral NerveInjury to the femoral nerve results in the loss of leg exten-sion and therefore loss of the knee jerk reflex.

Common Fibular NerveLoss of dorsiflexion and eversion of the foot as a result ofcommon fibular nerve damage leads to foot drop and footslap.

Superior Gluteal NerveInjury to the superior gluteal nerve results in paralysis ofgluteus medius and minimus, resulting in the inability tosteady the pelvis during walking, leading to a positiveTrendelenburg sign and a waddling gait.


Inferior Gluteal NerveParalysis of the gluteus maximus, as occurs with injury tothe inferior gluteal nerve results in weakness when extend-ing the thigh/hip, leading to difficulty rising from a seatedposition and climbing stairs.


Joints of lower limb(Figure 5-5)

Joint Type Articulation Structure MovementsHip Synovial Head of • Iliofemoral Flexion,

femur with (anterior), extension, acetabulum pubofemoral abduction,

(inferior), adduction, and ischio- medial rotation, femoral lateral rotation,(posterior) and circum-ligaments ductionsupport joint

• Acetabular labrum and transverse acetabular ligament deepen socket

• Ligamentumteres carriesthe artery tothe head of the femur

Femoro- Medial and • 5 extracap- Flexion, tibial (knee) lateral femoral sular liga- extension,

condyles with ments: medial medial and 1. Patellar rotation, and lateral condy- 2. Fibular lateral rotationles of tibia collateral

3. Tibial collateral

4. Oblique popliteal

5. Arcuate popliteal

• 4 intra-articular ligaments/structures:1. Anterior

cruciate

(continued)


2. Posterior cruciate

3. Medial menisci

4. Lateral menisci

• Popliteus tendon strengthens the joint

Superior • Superior: • Superior: • Superior: Small amount tibiofibular synovial head of anterior and of movement and tibio- • Inferior: fibula with posterior during fibular syn- fibrous tibial ligaments of dorsiflexiondesmosis condyle the head of (inferior) • Inferior: the fibula

fibula with strengthen tibia joint capsule

• Inferior: interosseousmembrane and anteriorand posteriortibiofibular and inferior transverse tibiofibular ligament strengthen joint

Talocrural Synovial Medial malle- • Lateral Dorsiflexion, (ankle) olus and distal ligament: plantarflexion

end of tibia calcaneo-and lateral fibular, an-malleolus of terior, and fibula with posterior the trochlea talofibularof the talus • Medial

(deltoid) ligament: anterior andposterior tibiotalar, tibionavicu-lar, and tibio-calcaneal strengthen and stabilizejoint

154

Joints of lower limb (continued)

Joint Type Articulation Structure Movements

(continued)


Additional ConceptThe inferior tibiofibular joint is the inferiormost part of thetibiofibular syndesmosis.



Joints of lower limb (continued)

Talocal- Inferior • Interosseous Inversion, caneal surface of talocalca- eversion(subtalar) talus with neal liga-

superior ment bindssurface of bodies of calcaneus calcaneus

and talus• Medial,

lateral, and posterior talocalca-neal liga-ment sup-ports joint

Intertarsal Between ad- Ligaments, Mainly gliding (talocal- jacent tarsal named for the movementscaneona- bones bones they vicular, connect, calcaneo- support jointcuboid, cuneona-vicular)

Tarsome- Distal tarsal Interosseous Glidingtatarsal bones with tarsometarsal,

proximal end dorsal, and of metatarsals plantar liga-

ments streng-then joint

Metatar- Head of meta- Plantar and Flexion, sophalan- tarsals with collateral extension, geal proximal ligaments abduction,

phalanges support joint adduction, and circumduction

Interpha- Heads of Plantar and Flexion, langeal proximal collateral extension

phalanges ligaments articulate with support jointmore distal phalanges



Fracturedfibula

Tornanterior

talofibularligament

Avulsionof fifth

metatarsal

Inversion of foot

Peroneusbrevis

muscle andtendon

FibulaMedialmalleolus

Cuboid

Tuberosity of5th metatarsal

Talus

FIGURE 5-4. Inversion injury. Inversion injuries are more com-

mon owing to the strength of the deltoid ligament (medial collat-

eral) on the medial side of the ankle; they are most likely to occur

during dorsiflexion, when the ankle is most unstable. (From Dudek

RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore:



Clinical SignificanceHip DislocationCongenital dislocation of the hip joint is common, particu-larly in girls.

Knee InjuriesAnterior cruciate ligament rupture allows the tibia to slideanteriorly relative to the femur—anterior drawer sign; poste-rior cruciate ligament rupture allows the tibia to slide poste-riorly relative to the femur—posterior drawer sign.

MnemonicStructures Posterior to Medial Malleolus

From anterior to posterior—Tom, Dick And Very NervousHarry

Tibialis posteriorextensor Digitorum longusposterior tibial Arteryposterior tibial Veintibial Nerve


Femur

Posteriorcruciateligament

Medialmeniscus

Tibia

Lateralmeniscus

Anteriorcruciateligament

FIGURE 5-5. Knee magnetic resonance image (coronal section

through the intercondylar notch). (From Dudek RW, Louis TM.

High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott Williams &

Wilkins; 2008:253.)


6 Upper Limb

158

INTRODUCTIONThe upper limb is divided for descriptive purposes by skele-tal elements into:

■ shoulder—portion between the arm and the thorax thatincludes the pectoral girdle: scapula and clavicle

■ arm—portion between the shoulder and elbow thatincludes the humerus

■ forearm—portion between the elbow and wrist thatincludes the radius and ulna

■ hand—portion distal to the wrist that includes themetacarpals and phalanges, the carpal bones form the wrist

SHOULDER REGION

Bone Feature SignificanceClavicle

Scapula

Bones of the shoulder(Figure 6-1)

• S-shaped, serves as strut to suspend limbaway from body

• Protects neurovascular bundle servingupper limb

• Attachment for pectoralis major—clavicular head, sternocleidomastoid—clavicular head, trapezius, subclavius, anddeltoid

Articulates with the acromion of thescapula at acromioclavicular joint

Articulates with the manubrium of thesternum at sternoclavicular joint

• Divides posterior aspect of scapula intosupra- and infraspinous fossae

• Attachment for trapezius and deltoid

Shaft

Acromial end

Sternal end

Spine

(continued)


CHAPTER 6 | UPPER LIMB 159


Bones of the shoulder (continued)

Attachment for supraspinatus

Attachment for infraspinatus

Attachment for subscapularis

• Expanded, lateral end of spine, forms“point” of the shoulder

• Articulates with acromial end ofclavicle

• Attachment for trapezius and deltoid

• Articulates with head of humerus atglenohumeral joint

• Deepened by glenoid labrum

Attachment for long head of biceps brachii

Attachment for long head of triceps brachii

• Attachment for biceps brachii (shorthead), coracobrachialis, and pectoralisminor muscles

• Attachment for coracoclavicular andcoracoacromial ligaments and thecostocoracoid membrane

• Transmits the suprascapular nerve• Bridged by the superior transverse

scapular ligament• The omohyoid attaches medial to the

notch

Attachment for teres major and serratusanterior

Attachment for levator scapulae,rhomboids (major and minor) and serratusanterior

Attachment for levator scapulae

Attachment for teres minor

Supraspinousfossa

Infraspinousfossa

Subscapularfossa

Acromion

Glenoid fossa

Supraglenoidtubercle

Infraglenoidtubercle

Coracoid process

Suprascapularnotch

Inferior angle

Medial border

Superior angle

Lateral border



Clavicle Bones of pectoralgirdle

Superiorangle

Sternalend

Medialborder

Inferiorangle

Lateral border

Anatomicalneck of humerus

Medialepicondyle

Trochlea

Coronoid process

Shaft (body)

Head

Styloid process

Carpal bones

Metacarpal bones

(1st) Proximal(2nd) Middle(3rd) Distal

Phalanges

Ulna

Distalphalanx

Proximalphalanx

Styloid

process

Shaft (body)

Tuberosity

Head

Capitulum

Lateral epicondyle

Shaft (body)

Coracoid process

Acromion

Deltoid tuberosity

Greater tubercle

Lesser tubercle

Radius

Humerus

Scapula

FIGURE 6-1. All bones, upper limb, anterior view.The right superior

appendicular skeleton includes the right half of the pectoral (shoulder)

girdle, composed of the right clavicle and scapula, and the skeleton of

the free right upper limb, formed by the remaining bones distal to the

scapula. (From Moore KL, Dalley AF. Clinically Oriented Anatomy.5th




Radialartery

Posteriorinterosseous

artery

Deep brachial artery

Subscapular artery

Circumflexhumeral arteries:

PosteriorAnterior

Thoracoacromial artery

Axiallary arterySubclavian artery

Dorsal scapular atery

Superficial palmar arch

Deep palmar arch

Ulnar artery

Anterior interosseous artery

Common interosseous artery

Brachial arteryThoracodorsal artery

Lateral thoracic aterySuperior thoracic artery

Thyrocervical trunk

FIGURE 6-2. Arteries of upper limb, anterior view. (From Tank

PW, Gest TR. LWW Atlas of Anatomy. Baltimore: Lippincott



Clinical SignificanceFracturesThe clavicle, the first bone to begin ossification, is one ofthe most commonly fractured bones. Fracture is usually evi-dent by the palpable elevation of the medial portion fromaction of the sternocleidomastoid and drooping of theshoulder from the unsupported weight of the upper limb.


Muscles of the shoulder

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsPectoralis major

Coracoidprocess

Greatertubercle

Shoulderjoint

Deltoidmuscle

Surgical neckof humerusInfraglenoid

tubercle

Axillary fat

Lateral borderof scapula

Anteroposterior View

Acromion

Site of acromioclavicular joint

Spine of scapula Clavicle

Superior borderof scapula

Superior angleof scapula

Tubercleof 1st rib

Vertebralborder ofscapula

FIGURE 6-3. Shoulder bone radiograph. (From Dudek RW, Louis



• Clavicularhead—medialhalf ofclavicle

• Sternalhead—sternum,superior 6costalcartilages

Lateral lipintertubercu-lar groove ofhumerus

Medial andlateralpectorals

• Adducts,flexes, andmediallyrotateshumerus

• Drawsscapulaanteriorly

(continued)



Muscles of the shoulder (continued)

Proximal Distal Main Muscle Attachment Attachment Innervation Actions

Pectoralis minor

Serratus anterior

Subclavius

Trapezius

Latissimus dorsi

Levator scapulae

Rhomboids—major and minor

and externalobliqueaponeu-rosis

Ribs 3–5

Ribs 1–8

Junction of1st rib andcostalcartilage

Superiornuchal line,externaloccipitalprotuberance,nuchalligament,C7–C12spinousprocesses

T6–T12spinousprocesses,thoracolum-bar fascia,iliac crest,and ribs9–12

C1–C4transverseprocesses

• Major—T2–T5spinousprocesses

Coracoidprocess ofscapula

Medialborder ofscapula

Middle 1⁄3of clavicle

Lateral 1⁄3of clavicle,acromion,spine, ofscapula

Floor ofintertuber-cular grooveof humerus

Medial borderand superiorangle ofscapula

• Major—medialborder ofscapula

Medialpectoral

Long thoracic

Nerve tosubclavius

Spinalaccessory

Thoracodorsal

Dorsalscapular

Stabilizesscapula

• Protracts androtatesscapula

• Holdsscapulaagainstthoracic wall

Depressesclavicle

• Elevation,depression,retraction ofscapula

• Rotatesglenoid fossasuperiorly

Extends,adducts,mediallyrotateshumerus

Elevatesscapula

(continued)



Muscles of the shoulder (continued)


Deltoid

Supraspinatus

Infraspinatus

Teres minor

Teres major

Subscapularis

• Minor—nuchalligamentC7–T11spinousprocesses

• Clavicle• Acromion

and spineof scapula

Supraspin-ous fossa ofscapula

Infraspinousfossa ofscapula

Lateralborder ofscapula

Inferiorangle ofscapula

Subscapularfossa ofscapula

• Minor—spine ofscapula

Deltoidtuberosity ofhumerus

Greatertubercle ofhumerus

Medial lip ofintertuber-cular grooveof humerus

Lessertubercle ofhumerus

Axillary

Suprascapular

Axillary

Lowersubscapular

Upper andlowersubscapular

Retract androtate scapula

Flexes andmedially rotates(anterior part),abducts (middlepart), extendsand laterallyrotates(posterior part)arm

• Initiatesabduction ofarm

• Rotator cuffmuscle

• Laterallyrotates arm


Adducts andmediallyrotates arm

• Adducts andmediallyrotates arm


Clinical SignificanceSerratus Anterior ParalysisWhen serratus anterior is paralyzed owing to injury of thelong thoracic nerve, the medial border moves laterally andposteriorly away from the thoracic wall, giving the scapulathe appearance of a wing—winged scapula.


MnemonicsLong Thoracic NerveC5–C7, raise your wings to heaven.C5–C7 (cord levels found within the serratus anterior)

injury causes inability to “raise” arm past 90 degrees (to heaven) and results in a winged scapula.

SALT—Serratus Anterior; Long Thoracic nerve

Rotator CuffThe humeral head SITS in the glenoid fossa because of therotator cuff muscles—Supraspinatus, Infraspinatus, TeresMinor, Subscapularis.


Nerves of the shoulder


Supraclavicular Cervical plexus (C3–C4) Sensory to skin of shouldernerves

Axillary Posterior cord Teres minor, shoulder joint, deltoid,skin of shoulder

Dorsal scapular C5 Rhomboids, levator scapulae

Spinal accessory 1st few cervical spinal Trapezius and sternocleidomastoid(CN XI) cord segments

Clinical SignificanceAxillary NerveThe deltoid atrophies when the axillary nerve is damaged,as happens during fracture of the surgical neck of thehumerus or inferior dislocation of the glenohumeral joint.A loss of sensation over the proximal arm accompanies atro-phy of the deltoid.

Artery Origin DescriptionSubclavian—right and left

Vessels of the shoulder(Figure 6-2)

• Right—brachiocephalictrunk

• Left—arch of theaorta

• Ends at lateral border of 1st rib tobecome the axillary

• Gives rise to vertebral, internalthoracic, and thyrocervical trunk

(continued)



Artery Origin DescriptionInternal thoracic

Thyrocervical trunk

Suprascapular

Transverse cervical

Axillary

Superior thoracic

Thoracoacro-mial

Lateral thoracic

Circumflex humeral (anterior and posterior)

Subscapular

Circumflex scapular

Thoracodorsal

Vessels of the shoulder (continued)

1st part ofsubclavian

Thyrocervical trunk

Subclavian at lateralborder of 1st rib

1st part of axillary

2nd part of axillary

3rd part of axillary

Subscapular

Gives rise to anterior intercostals,musculophrenic, superior epigastric,and pericardiacophrenic

Gives rise to suprascapular, transversecervical, inferior thyroid, and ascendingcervical

Supplies shoulder region

• 1st part—superior thoracic• 2nd part—thoracoacromial, lateral

thoracic• 3rd part—anterior humeral

circumflex, posterior humeralcircumflex, and subscapular

Supplies 1st and 2nd intercostalspaces, serratus anterior

Gives rise to pectoral, deltoid,acromial, and clavicular branches

Supplies lateral aspect of breast

Supplies area around neck of humerus

Gives rise to circumflex scapular andthoracodorsal

Supplies scapular region

Supplies latissimus dorsi


Clinical SignificanceAxillary ArteryThe axillary artery can be compressed against thehumerus or the first rib if profuse bleeding occurs.Branches of the axillary artery contribute to the extensiveanastomoses around the scapula, which may serve to protect


the limb during occlusion or compression of the primaryarterial pathways.

Aneurysm of the axillary artery may compress the trunksof the brachial plexus, leading to pain and anesthesia in theareas supplied by the affected nerves.

MnemonicsAxillary Artery BranchesThe axillary artery is divided into three parts by the pectoralisminor.The parts correspond to the number of branches:

1. Part 1—proximal to pectoralis minor has one branch:superior thoracic

2. Part 2—deep to pectoralis minor has two branches: tho-racoacromial and lateral thoracic arteries

3. Part 3—distal to pectoralis minor has three branches:anterior and posterior humeral circumflex and the sub-scapular trunk

Send The Lord to Say A Prayer—proximal to distalbranches off of the axillary artery:

Superior ThoracicThoracoacromialLateral ThoracicSubscapularAnterior Circumflex HumeralPosterior Circumflex Humeral

Thoracoacromial Trunk BranchesCAlifornia Police Department—branches of the

thoracoacromial trunk:ClavicularAcromialPectoralDeltoid

ARM REGION


Bone Characteristic SignificanceHumerus Head

Bones of the arm(Figures 6-1, 6-3, and 6-7)

Articulates with glenoid fossa of thescapula to form glenohumeral joint

(continued)




Greater tubercle

Lesser tubercle

Anatomical neck

Surgical neck

Intertubercular groove (bicipital groove)

Lateral epicondyle

Medial epicondyle

Lateral supracondylar ridge

Medial supracondylar ridge

Trochlea

Capitulum

Radial fossa

Olecranon fossa

Coronoid fossa

Bones of the arm (continued)

• Lateral aspect of humerus• Attachment for supraspinatus,

infraspinatus, and teres minor

• Medial aspect of humerus• Attachment for subscapularis

Attachment for glenohumeral joint capsule

• Common site for humeral fracture• Distal to greater and lesser tubercles• Axillary nerve and posterior humeral

circumflex artery are found nearby and aresubject to injury during fracture at the neck

• Located between the greater and lessertubercles

• Transmits tendon of the long head of thebiceps brachii

• Bridged by the transverse humeralligament

• Lateral lip attachment for pectoralis major• Floor attachment for latissimus dorsi• Medial lip attachment for teres major

Attachment for common extensor tendon ofthe forearm and the supinator

Attachment for common flexor tendon of theforearm and pronator teres

Attachment for brachioradialis, extensorcarpi radialis longus and medial head oftriceps brachii

Attachment for brachialis and the medialhead of triceps brachii

Articulates with trochlear notch of ulna

Articulates with head of radius

Receives the head of the radius duringforearm flexion

Receives olecranon of the ulna duringforearm extension

Receives coronoid process of ulna duringforearm flexion

(continued)


MnemonicIntertubercular Groove Muscle AttachmentsThe lady between two majors.Teres major attaches to the medial lip of the intertubercu-

lar groove.Pectoralis major attaches to the lateral lip of the

intertubercular groove.Latissimus (lady) Dorsi attaches to the floor of the groove,

between the two majors.

Clinical SignificanceFracturesMost humeral fractures occur at the surgical neck, resultingin an impacted fracture. A fall on the acromion may result inan avulsion fracture in which the greater tubercle is pulledaway from the humerus. A direct blow to the arm may resultin a transverse or spiral fracture of the shaft, whereas an inter-condylar fracture may occur during a fall on a flexed elbow.


Muscles of the arm

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsCoraco-brachialis

Biceps brachii

Brachialis

Coracoidprocess

• Long head—supraglenoidtubercle

• Short head—coracoidprocess

Distal humerus,including medialsupracondylarridge

Humerus

Radialtuberosity

Ulnartuberosity

Musculocutaneous

Musculocutaneous

Musculocutaneous

Flexes andadductsarm

Flexes armandforearm,supinates

Flexesforearm

(continued)

Bones of the arm (continued)

Bone Characteristic SignificanceRadial (spiral) groove

Deltoid tuberosity

• Transmits the deep brachial artery andradial nerve

• Separates the proximal attachments of thelateral head (lateral to groove) and medialhead (medial to groove) of the triceps brachii

Attachment for deltoid



Muscles of the arm (continued)

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsTriceps brachii

Anconeus

• Long head—infraglenoidtubercle

• Lateralhead—lateral toradial groove

• Medialhead—medial toradial groove,medial andlateralsupracondylarridges

Lateralepicondyle

Olecranonprocess

Olecranonprocess

Radial

Radial

Extendsforearm

Extendsforearm

MnemonicBiceps Brachii AttachmentsYou ride shorter to the street corner and ride longer on

the superhighway.—Short head of the biceps brachii attaches to the coracoid

process.Long head of the biceps brachii attaches to the supragle-

noid tubercle.

Clinical SignificanceTendonitis of the Biceps BrachiiBiceps tendonitis, inflammation of the tendon of the longhead, is the result of repetitive movement of the tendon inthe intertubercular groove, as occurs in sports that involvethrowing. Rupture of the tendon may occur as the tendon istorn from the supraglenoid tubercle.

Nerves of the arm

Nerve Origin Structures InnervatedDorsal scapular

Long thoracic

Suprascapular

Nerve to subclavius

C5

Superior trunk

Rhomboids, levator scapulae

Serratus anterior

Supraspinatus and infraspinatus

Subclavius

(continued)



Nerves of the arm (continued)

Nerve Origin Structures InnervatedLateral pectoral

Musculocutaneous

Median

Medial pectoral

Ulnar

Upper subscapular

Lower subscapular

Thoracodorsal

Axillary

Radial

Lateral cord

Lateral cordand medialcord

Medial cord

Posterior cord

Pectoralis major

• Anterior compartment of the arm• Sensory to lateral forearm

• Anterior compartment of the forearm(except flexor carpi ulnaris and theulnar half of flexor digitorumprofundus), muscles of the thenareminence and the first 2 lumbricals

Pectoralis minor and major

• Flexor carpi ulnaris and the ulnar halfof flexor digitorum profundus

• Most muscles of the hand• Sensory to hand medial to digit 4

Subscapularis

Subscapularis and teres major

Latissimus dorsi

• Teres minor, deltoid• Shoulder joint, sensory to skin over

shoulder

• Posterior compartments of arm andforearm

• Sensory to skin of posterior arm,forearm, and hand

Clinical SignificanceThoracodorsal Nerve InjuryInjury to the thoracodorsal nerve, as may occur duringresection of axillary lymph nodes in breast cancer, causesparalysis of the latissimus dorsi. The person is then unableto raise the trunk with the upper limbs or use an axillarycrutch.

Artery Origin DescriptionAxillary

Arm vessels(Figure 6-2)

Subclavian at lateralborder of 1st rib

• 1st part—superior thoracic• 2nd part—thoracoacromial, lateral

thoracic• 3rd part—anterior circumflex humeral,

posterior circumflex humeral, andsubscapular

(continued)




Circumflex humeral (anterior andposterior) arteries

Subscapularartery

Circumflex scapular artery

Thoracodor-sal artery

Brachial artery

Deep brachial artery

Superior ulnar collateral artery

Inferior ulnar collateral artery

Arm vessels (continued)

3rd part of axillary

Subscapular

Axillary after lateralborder of teresmajor

Brachial

Supplies area around neck of humerus

Gives rise to circumflex scapular andthoracodorsal

Supplies scapular region

Supplies latissimus dorsi

• Continuation of axillary• Terminates in elbow region to form

radial and ulnar arteries

• Supplies posterior compartment ofarm and elbow joint

• Runs in radial groove with radial nerve

Supplies elbow region


Clinical SignificanceBrachial ArteryCompression of the brachial artery is best accomplishedalong the medial humerus in the mid-arm region. Collateralcirculation through the deep brachial artery allows for per-fusion distal to the compression.


FOREARM REGION


Bone Characteristic SignificanceRadius Head

Radial tuberosity

Ulnar notch

Styloid process

Ulna Olecranon

Coronoid process

Trochlear notch

Ulnar tuberosity

Radial notch

Supinator crest

Supinator fossa

Head

Styloid process

Bones of the forearm(Figures 6-1 and 6-7)

• Articulates with capitulum of humerus andradial notch of ulna

• Held in place by the anular ligament

Attachment for biceps brachii

Articulates with head of ulna

Attachment for brachioradialis and radialcollateral ligament

Attachment for flexor carpi ulnaris (ulnarhead), triceps brachii, anconeus, and ulnarcollateral ligament

• Articulates with coronoid fossa ofhumerus during flexion

• Attachment for pronator teres, flexordigitorum superficialis and ulnar collateralligament

Articulates with trochlea of humerus

Attachment for brachialis

Articulates with head of radius

Attachment for supinator

Articulates with ulnar notch of radius andarticular disc of the wrist

Attachment for ulnar collateral ligament

Clinical SignificanceFracturesAs a result of attempting to break a fall with the outstretchedlimb a Colles’ fracture may occur. A Colles’ fracture is atransverse fracture of the distal radius, often accompaniedby an avulsed styloid process of the ulna. The result is aposterior angulation of the forearm, just proximal to thewrist—a dinner fork deformity.

Fractured ElbowFracture of the olecranon—a fractured elbow, is oftencaused by a fall.The triceps brachii pulls the avulsed pieceof bone in this painful and debilitating injury.



Muscles of the forearm

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsPronator teres

Flexor carpi radialis

Palmaris longus

Flexor carpi ulnaris

Flexor digitorum superficialis

Flexor digitorum profundus

Flexor pollicis longus

Pronator quadratus

Brachiora-dialis

Extensor carpi radialis longus

Medialepicondyle ofhumerus andcoronoidprocess of ulna

Medialepicondyle ofhumerus

Medialepicondyle ofhumerus andolecranonprocess andposterior ulna

Medialepicondyle ofhumerus andcoronoidprocess of ulnaand anteriorradius

Ulna andinterosseousmembrane

Radius andinterosseousmembrane

Ulna

Lateralsupracondylarridge ofhumerus

Mid-radius

2ndmetacarpal

Flexorretinaculumand palmaraponeurosis

Pisiform,hook ofhamate and5thmetacarpal

Middlephalanges ofmedial 4digits

Distalphalanges ofmedial 4digits

Distalphalanx ofthumb

Radius

Styloidprocess ofradius

2ndmetacarpal

Median

Ulnar

Median

Medialpart—ulnar;lateralpart—median

Anteriorinterosseous(median)

Radial

Pronates andflexes elbow

Flexes wristand abductshand

Flexes wrist

Flexes wristand adductshand

Flexes proximalinterphalangealjoints of medial4 digits andflexesmetacarpopha-langeal jointsand flexes wrist

Flexes distalinterphalangealjoints of medial4 digits andflexes wrist

Flexes thumb

Pronates

Flexes forearm

Extends handand abductswrist

(continued)



Muscles of the forearm (continued)

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsExtensor carpi radialis brevis

Extensor digitorum

Extensor digiti minimi

Extensor carpi ulnaris

Supinator

Abductor pollicis longus

Extensor pollicis longus

Extensor pollicis brevis

Extensor indicis

Lateralepicondyle ofhumerus

Lateralepicondyle ofhumerus andulna

Lateralepicondyle ofhumerus, radialcollateralligament, anularligament,supinator crest,and fossa ofulna

Ulna, radius,and inter-osseous mem-brane


Radius andinterosseousmembrane


3rdmetacarpal

Extensorexpansion ofmedial 4digits

5th digitextensorexpansion

5thmetacarpal

Proximalradius

1stmetacarpal

Distalphalanx ofthumb

Proximalphalanx ofthumb

2nd digitextensorexpansion

Deep radial(radial)

Posteriorinterosseous(radial)

Deep radial(radial)

Posteriorinterosseous(radial)

Extends medial4 digits

Extends 5thdigit

Extends handand adductswrist

Supinates

Abducts thumb

Extends thumb

Extends 2nddigit

MnemonicsRelationship of Flexor Tendons in the DigitsSuperficialis splits in two to permit profundus to passthrough.



Relationship of Flexors in the Anterior ForearmTuck your thumb into your palm; lay your hand on yourproximal forearm with the fingers pointed toward yourhand.Your fingers represent the top layer of muscles:

2nd digit—pronator teres3rd digit—flexor carpi radialis4th digit—palmaris longus5th digit—flexor carpi ulnaris

1st digit (thumb) represents the intermediate musclelayer—flexor digitorum superficialis

Clinical SignificanceElbow TendonitisElbow tendonitis, or tennis elbow, is caused by repetitiveuse of the superficial extensor muscles of the forearm.

Forearm nerves


Median

Anterior interosseous

Ulnar

Radial

Deep branch of radial

Posterior interosseous

Posterior cutaneous nerve of the forearm

Union of lateral root(lateral cord) andmedial root (medialcord)

Median

Medial cord ofbrachial plexus

Posterior cord ofbrachial plexus

Radial

Deep branch ofradial

Radial

Pronator teres, flexor carpi radialis,palmaris longus, and flexor digitorumsuperficialis

Lateral aspect of flexor digitorumprofundus, flexor pollicis longus, andpronator quadratus

Medial aspect of flexor digitorumprofundus and flexor carpi ulnaris

Brachioradialis and extensor carpiradialis longus

Extensor carpi radialis brevis, andsupinator

Extensor digitorum, extensor digitiminimi, extensor carpi ulnaris, abductorpollicis longus, extensor pollicis longus,extensor pollicis brevis, and extensorindicis

Posterior aspect of the forearm

(continued)



Forearm nerves (continued)

Nerve Origin Structures InnervatedLateral cutaneous nerve of the forearm

Medial cutaneous nerve of the forearm

Musculocutaneous

Medial cord ofbrachial plexus

Lateral aspect of the forearm

Medial aspect of the forearm

MnemonicRadial NerveThe radial nerve innervates the BEST muscles—

BrachioradialisExtensorsSupinatorTriceps Brachii

Artery Origin DescriptionUlnar

Radial

Anterior ulnar recurrent

Posterior ulnar recurrent

Common interosseous

Anterior interosseous

Posterior interosseous

Recurrent interosseous

Palmar carpal branch

Dorsal carpal branch

Radial recurrent

Palmar carpal branch

Dorsal carpal branch

Vessels of the forearm(Figure 6-2)

Terminal branch of the brachial


Gives rise to anterior and posteriorinterosseous

Supplies anterior aspect of forearm

Supplies posterior aspect of forearm


Contributes to palmar carpal arch

Contributes to dorsal carpal arch


Contributes to palmar carpal arch

Contributes to dorsal carpal arch

Brachial

Ulnar

Posteriorinterosseous

Ulnar

Radial


Commoninterosseous


MnemonicArterial Anastomosis at ElbowI Am Pretty Smart

Inferior ulnar collateral artery anastomoses with theAnterior ulnar recurrent artery. Posterior ulnar recurrentartery anastomoses with the Superior ulnar collateral artery.

HAND REGION



Scaphoid Tubercle • Attachment for abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, radial collateral ligament, and flexor retinaculum (tubercle)

• Articulates with radius, trapezium, lunate, capitate, and trapezoid

• Most commonly fractured carpal bone

Lunate Crescent-shaped • Articulates with radius, scaphoid, tri-quetrum, capitate, and hamate

• Most frequently dislocated carpal bone

Trique- Pyramid-shaped • Articulates with pisiform, hamate and lunatetrum • Attachment for ulnar collateral ligament

Pisiform Spheroidal • Articulates with triquetrum• Attachment for flexor retinaculum, flexor

carpi ulnaris, and abductor digiti minimi

Trape- Tubercle • Attachment for flexor retinaculum, opponenszium pollicis, abductor pollicis brevis, and flexor

pollicis brevis• Articulates with scaphoid, 1st and 2nd

metacarpals, and trapezoid

Trapezoid Wedge-shaped Articulates with scaphoid, 2nd metacarpal, trapezium, and capitate

Capitate Head • Attachment for adductor pollicis• Articulates with scaphoid; lunate; 2nd, 3rd,

and 4th metacarpals; trapezoid; and hamate• Largest carpal bone

Hamate Hamulus Attachment for flexor retinaculum, opponens digiti minimi, flexor carpi ulnaris, flexor digitiminimi; articulates with lunate, 4th and 5th metacarpals, triquetrum, and capitate

Bones of the hand(Figures 6-1 and 6-4)

(continued)




Bones of the hand (continued)

Metacar- Heads Articulate with proximal phalangespals (5)

Proximal Articulate with more distal phalangespha-langes (5)

Middle pha-langes (5)

Distal Tuberosity Ungual tuberosity supports the fingernailpha-langes (4)

Scaphoid

Radius

Capitate

Lunate

FIGURE 6-4. Scaphoid fracture. The scaphoid is the most fre-

quently fractured carpal bone; fractures may result from a fall on

the palm. (From Dudek RW, Louis TM. High-Yield Gross Anatomy.3rd ed. Baltimore: Lippincott Williams & Wilkins; 2008:235.)


MnemonicCarpal Bones

She Looks To Pretty, Try To Catch HerScaphoid, Lunate,Triquetrum, Pisiform, Trapezium,

Trapezoid, Capitate, Hamate

The trapezium is nearest the thumb—trapeze-e-thumb.

Clinical SignificanceFracturesThe scaphoid is the most frequently fractured carpal boneand occurs from a fall on the palm when the wrist isabducted.

Fracture of the 5th metacarpal, a boxer’s fracture,occurs when an unskilled person punches someone, causingthe head of the bone to rotate over the distal shaft.

Injuries of the phalanges are common and are extremelypainful, often resulting from crush injuries.


Proximal DistalMuscle Attachment Attachment Innervation Main ActionsThenar MusclesOpponens Flexor retinacu- 1st meta- Recurrent Rotates and pollicis lum, trapezium carpal branch of draws 1st meta-

median carpal medially

Abductor Flexor Proximal Abducts thumb,pollicis retinaculum, phalanx helps opposition

trapezium, and of thumbscaphoid

Flexor Flexor • Superficial Flexes thumbpollicis retinaculum, head—brevis and trapezium recurrent

branch of median

• Deephead—deepbranch of ulnar

Adductor • Oblique Deep branch Adducts thumbpollicis head—2nd of ulnar

and 3rd meta-carpals, capi-tate and adjacent carpals

Muscles of the hand

(continued)




Muscles of the hand (continued)

• Transverse head—3rd metacarpal

Hypothenar MusclesAbductor Pisiform Proximal Deep branch Abducts 5thdigiti phalanx of of ulnar digitminimi 5th digit

Flexor Flexor Flexes 5th digitdigiti retinaculumminimi and hamate

Opponens 5th meta- Opposes 5th digiti carpal digit with thumbminimi

Short Muscles—Lumbricals and Interossei1st and Tendons of Extensor Median Flex digits at 2nd lum- flexor digito- expansions of metacarpopha-bricals rum profundus digits 2–5 langeal joints

3rd and Deep branch and extend at

4th lum- of ulnar interphalangeal

bricals joints

Palmar 2nd, 4th, and Proximal pha- • Adduct 2nd, interossei 5th metacarpals langes and 4th, and 5th

extensor digitsexpansions of • Flex digits at2nd, 4th, and metacarpo-5th digits phalangeal

joints and extend at interpha-langeal joints

Dorsal Metacarpals Proximal pha- Abduct 2nd–4thinterossei langes and digits; flex digits

extensor at metacarpo-expansions phalangeal of 2nd–4th joints anddigits extend at inter-

phalangeal joints


MnemonicsInnervation of Hand MusculatureMeat LOAF muscles—Median nerve innervates the firsttwo Lumbricals, Opponens Pollicis, Abductor PollicisBrevis and Flexor Pollicis Brevis in the hand.

Interossei FunctionPAd and DAb—Palmer interossei Adduct, Dorsal interosseiAbduct.


Hand nerves

Nerve Origin Structures InnervatedMedian Union of lateral Opponens pollicis, abductor pollicis

root (lateral brevis, superficial head of flexor polliciscord) and brevis, and 1st and 2nd lumbricalsmedial root (medial cord)

Palmar cutaneous Median Sensory over palm, sides of digits 1–3,branch of median lateral side of 4th digit, and dorsum of

of distal aspect of digits 1–4

Ulnar Medial cord of Opponens digiti minimi, flexor digitibrachial plexus minimi brevis, abductor digiti minimi,

3rd and 4th lumbricals, adductor pollicis,deep head of flexor pollicis brevis, and the palmar and dorsal interossei

Palmar cutaneous Ulnar Sensory to medial aspect of palm,branch of ulnar 5th digit and medial half of 4th digit

Dorsal cutaneous Sensory to medial aspect of dorsum, branch of ulnar 5th digit and medial half of 4th digit

Superficial branch Radial Sensory to lateral 2⁄3 of dorsum of of radial hand, thumb and lateral 11⁄2 digits

Vessels of the hand(Figure 6-2)

Artery Origin DescriptionSuperficial palmar Continuation of the Common palmar digital arteriesarch ulnar with contri-

bution from radial

Deep palmar arch Continuation of the Palmar metacarpal arteriesradial with contri-bution from the ulnar

(continued)



Palmar ArchesThe superficial palmar arch is more distal (in line with thedistal margin of the extended thumb); the deep arch is moreproximal.

Clinical SignificancePalmar ArchBleeding is usually profuse and difficult to control whenthe palmar arches are lacerated. Often, it is necessary to compress the brachial artery in the arm to limit thebleeding.

MISCELLANEOUS


Vessels of the hand (continued)

Artery Origin DescriptionCommon palmar Superficial palmar Proper palmar digitalsdigitals arch

Proper palmar Common palmar Supplies digitsdigitals digitals

Princeps pollicis Radial Supplies thumb

Radialis indicis Supplies 2nd digit

Dorsal carpal arch Radial and ulnar Supplies wrist

Palmar carpal arch

Area Structure SignificanceAxilla 4-sided, fat-filled, pyramidal • Permits passage of neuro-

space inferior to glenohumeral vascular elements to andjoint and superior to axillary fascia: from the upper limb—• Apex: cervicoaxillary canal— contains axillary artery and

passageway between neck vein, major portion of theand axilla brachial plexus, and lymph

• Base: axillary fascia nodes• Anterior wall: pectoralis major

and minor

Areas of the upper limb

(continued)



Area Structure Significance

Areas of the upper limb (continued)

• Posterior wall: subscapularis, • Axillary sheath: extension ofteres major, and latissimus dorsi cervical (prevertebral) fascia

• Medial wall: thoracic wall and that ensheathes proximal serratus anterior end of neurovascular

• Lateral wall: humerus elements

Quadran- Boundaries: Permits passage of the axillary gular • Superior: teres minor nerve and posterior humeral space • Inferior: teres major circumflex artery to posterior

• Medial: long head of triceps aspect of shoulderbrachii

• Lateral: humerus

Upper Boundaries: Permits passage of the circum-triangular • Superior: teres minor flex scapular artery to space • Inferior: teres major posterior aspect of shoulder

• Lateral: long head of triceps brachii

Lower Boundaries: Permits passage of radial triangular • Superior: teres major nerve and deep brachial artery space • Medial: long head of triceps to posterior aspect of arm

brachii• Lateral: medial head of triceps

brachii

Cubital Triangular depression on anterior • Contains: brachial artery and fossa aspect of elbow, boundaries: its division into radial and

• Superior: imaginary line ulnar arteries (and their between the medial and lateral accompanying deep veins), epicondyles biceps brachii tendon, and

• Medial: pronator teres median nerve• Lateral: brachioradialis • Median cubital vein lies • Floor: brachialis superficial to bicipital • Roof: bicipital aponeurosis aponeurosis

Carpal Cup-shaped (concave anteriorly) Conveys the tendons of thetunnel passageway from the forearm flexor digitorum superficialis,

to the hand; boundaries: flexor digitorum profundus • Lateral: scaphoid and trapezoid andflexor pollicis longus, and • Medial: hamate and pisiform the median nerve• Roof (anterior): flexor retinaculum

Delto- • Triangular area bounded by Pierced by cephalic vein, pectoral the clavicle, deltoid and pecto- branches of the thoracoacromialtriangle ralis major trunk and lateral pectoral

• Covered by clavipectoral fascia nerve located within

Anatomic Triangular area bounded medially • Floor is formed primarily snuff-box by the tendon of extensor pollicis by the scaphoid

longus, laterally by the tendons • Radial artery passes of extensor pollicis brevis and through—the radial pulse abductor pollicis longus may be taken here


MnemonicStructures in the Cubital FossaTAN—structures found within the cubital fossa from lateralto medial:

Tendon: biceps brachiiArtery: brachialNerve: median

Clinical SignificanceAxillaWounds in the axilla often involve the axillary vein, becauseof its large size and superficial position.

Carpal TunnelCarpal tunnel syndrome results from anything that limitsthe space in the carpal tunnel and is characterized by loss ofsensation over the first digit, the inability to oppose thethumb, and thenar wasting from the compromised functionof the median nerve.


Superficial structures of the upper limb

Structure Course/SignificanceVesselCephalic vein • Origin: dorsal venous network; runs along lateral

aspect of upper limb• Enters deltopectoral triangle, pierces costocoracoid

membrane to join axillary vein

Basilic vein • Origin: dorsal venous network; runs along medialaspect of upper limb

• Pierces the brachial fascia at mid-arm to join with thebrachial veins to form the axillary vein

Median cubital • Joins the cephalic and basilic veins over the cubital vein fossa

• Supported by the bicipital aponeurosis

Median vein of • Origin: dorsal venous networkthe forearm • Courses between and enters the cephalic or basilic

veins at the elbow

Dorsal venous Highly variable superficial venous network on dorsumnetwork of hand

Lymphatics of • Superficial lymphatic vessels accompany veins to enter upper limb superficial lymph nodes

• Includes: cubital and axillary groups

(continued)



Superficial structures of the upper limb (continued)

Clinical SignificanceMedian Cubital VeinThe median cubital vein is the common vein selected forvenipuncture because of its accessibility and superficial rela-tionship to the bicipital aponeurosis, which supplies someprotection to the underlying brachial artery.

Cutaneous NerveSupraclavicular • Origin: cervical plexus (C3–C4)nerves • Sensory to skin of shoulder

Posterior cuta- • Origin: Radial nerveneous nerve of the • Sensory to skin of posterior aspect of armarm

Superior lateral • Origin: continuation of axillary nervecutaneous nerve • Sensory to lateral aspect of arm (proximally)of the arm

Inferior lateral • Origin: radial nervecutaneous nerve • Sensory to skin over lateral aspect of arm (distally)of the arm

Intercostobrachial • Origin: 2nd intercostal nerve• Sensory to medial aspect of arm

Medial cutaneous • Origin: medial cordnerve of the arm • Sensory to medial aspect of arm

Medial cutaneous • Origin: medial cordnerve of the • Sensory to medial aspect of forearmforearm

Posterior • Origin: radial nervecutaneous nerve • Sensory to posterior aspect of forearmof the forearm

Lateral cutaneous • Origin: axillary nervenerve of the arm • Sensory to lateral aspect of arm

Lateral cutaneous • Origin: continuation of musculocutaneousnerve of the • Sensory to the lateral aspect of the forearmforearm

Terminal branches Sensory over palm, sides of digits 1–3, lateral side ofof the median 4th digit, and dorsum of distal aspect of digits 1–4

Terminal branches Sensory to lateral 2⁄3 of dorsum of hand, thumb,of the radial and lateral 11⁄2 digits

Terminal branches Sensory to medial aspect of palm and dorsum, 5th digit,of the ulnar and medial half of 4th digit

Structure Course/Significance



C4

C3

C5T1T2T3T4T5T6T7T8T9T10

T11T12

L1

L2

L3

L4

L5

S1

C6

C7

C8

C5

T1

C2

C3C4C5

C7C6C8

T1

T3

T5

T7

T9

T11L1L3

L5

T2

T4

T6

T8

T10

T12L2L4

S2S1

S1S2

S3S4S5

L1

L2

L3

L4

L4

L5

Anterior view Posterior view

FIGURE 6-5. Dermatome maps of the body are based on accu-

mulation of clinical findings following spinal nerve injuries; this

map is based on the studies of Keegan and Garrett (1948). Spinal

nerve C1 lacks a significant afferent component and does not sup-

ply the skin; therefore, no C1 dermatome is depicted. (From Moore

KL, Dalley AF. Clinically Oriented Anatomy. 5th ed. Baltimore:




Fascia/Connective Tissue Significance/StructurePectoral Investing fascia of pectoralis major

Axillary Forms floor of axilla

Clavipectoral Encloses subclavius and pectoralis minor

Costocoracoid membrane • Clavipectoral fascia between pectoralis minor and subclavius

• Pierced by lateral pectoral nerve

Suspensory ligament of • Clavipectoral fascia inferior to pectoralis minorthe axilla • Supports axillary fascia and forms axillary

fossa on abduction

Deltoid fascia Investing fascia of deltoid is continuous with pectoral and infraspinous fascia

Brachial fascia • Sheath of deep fascia surrounding arm• Attaches distally to humeral condyles and

olecranon process of ulna• Continuous with antebrachial, pectoral,

deltoid, axillary, and infraspinous fasciae• Gives rise to medial and lateral intermuscular

septa, which divide arm into anterior and posterior compartments

Antebrachial fascia • Sheath of deep fascia surrounding forearm• Continuous with brachial fascia• Intermuscular septa and the interosseous

membrane divide the forearm into anterior and posterior compartments

Extensor retinaculum Posterior thickening of antebrachial fascia over distal ulna and radius—holds extensor tendonsin place

Flexor retinaculum Anterior thickening of antebrachial fascia over carpal bones—forms carpal tunnel

Palmar fascia • Continuous with antebrachial fascia• Central portion—palmar aponeurosis

Superficial transverse Forms base of palmar aponeurosiscarpal ligament

Fascia of the upper limb

Brachial plexus(Figure 6-6)

Nerve Significance/StructureRoots • Anterior rami of C5–T1

• C5 gives rise to the dorsal scapular nerve and nerve to subclavius

• C5–C7 give rise to the long thoracic nerve

(continued)


MnemonicsParts of the Brachial Plexus From proximal to distal:

Real—RootsTruckers—TrunksDrink—DivisionsCold—CordsBeer—Branches

Terminal Branches of the Brachial PlexusTerminal branches lateral to medial—

My Audi Races My Uncle.Musculocutaneous, Axillary, Radial, Median, Ulnar


Brachial plexus (continued)

Nerve Significance/Structure

Superior trunk • Formed by the C5 and C6 roots• Gives rise to the nerve to subclavius and the supras-

capular nerve

Middle trunk Continuation of C7 root

Inferior trunk Formed by the C8 and T1 roots

Divisions • Each trunk terminates by dividing into an anterior and a posterior division

• No branches off the divisions

Lateral cord • Formed by junction of anterior divisions from the superior and middle trunks

• Lateral to axillary artery• Gives rise to the lateral pectoral nerve• Terminates by dividing into the musculocutaneous

nerve and lateral root of the median nerve

Posterior cord • Formed by the posterior divisions of all 3 cords• Posterior to axillary artery• Gives rise to the upper and lower subscapular and

thoracodorsal nerves• Terminates by dividing into the axillary and radial

nerves

Medial cord • Formed by the anterior division of the inferior trunk• Medial to axillary artery• Gives rise to the medial pectoral, medial brachial

cutaneous, and medial antebrachial cutaneous nerves• Terminates by dividing into the ulnar nerve and the

medial root of the median nerve


Pectoral NervesLateral Less, Medial More—The Lateral pectoral nerve onlypasses through the pectoralis major, whereas the Medialpectoral nerve passes through both pectoralis major andminor.

Branches of the Posterior CordBranches off the posterior cord: STAR—Subscapulars(upper and lower), Thoracodorsal, Axillary, Radial

Identification TipThe musculocutaneous, median, and ulnar nerves forman “M” on the anterior aspect of the axillary artery,making their identification a good starting point for theregion.


Ulnar nerve(C7–C8, T1)

Radial nerve(C5–C8, T1)

Upper subscapular nerve (C5–C6)Thoracodorsal (middle subscapular)nerve (C6–C8)

Lower subscapular nerve (C5–C6)

Medial antebrachial cutaneousnerve (C8, T1)

Medial brachial cutaneous nerve (T1)Medial pectoral nerve (C8, T1)

1st intercostal nerve

1st rib Long thoracicnerve (C5–C7)

To longuscolli and scalenemuscles(C5–C8)

T1

C8

C7

C6

C5

Dorsalramus

Dorsal scapularnerve (C5)

C5 contributionto phrenic nerve

Nerve to subclaviusmuscle (C5–C6)

Suprascapularnerve (C5–C6)

Lateral pectoralnerve (C5–C7)

Musculocutaneousnerve (C5–C7)

Axillary nerve(C5–C6)

Median nerve(C5–C8, T1)

Lateral Posterior

Medial

Superior

Middle

Inferior

Terminalbranches

3 Cordsaround axillary artery

3 Anteiror divisions3 Posterior divisions

3 Trunks

5 Roots (ventral rami ofspinal nerves C5–T1)

FIGURE 6-6. Brachial plexus. (From Tank PW, Gest TR. LWWAtlas of Anatomy. Baltimore: Lippincott Williams & Wilkins;

2009:43.)


Brachial Plexus VariationsVariations in the form of the brachial plexus are commonand may include contributions from additional anterior ramisuch as C4 or T2 or alterations in the branches, divisions,cords, or trunks.

Clinical SignificanceBrachial Plexus InjuriesInjuries to the superior parts of the brachial plexus usuallyresult from an excessive increase in the angle between theneck and shoulder, as occurs during a fall increasing theangle between the two or excessive stretching of a baby’shead and neck during delivery. Injury to the superior part ofthe plexus is apparent by the characteristic “waiter’s tip”position, in which the limb is medially rotated, the shoulderadducted and the elbow extended.

Injuries to the inferior parts of the brachial plexus occurwhen the upper limb is pulled superiorly, as in graspingsomething to break a fall or a baby’s upper limb is pulledduring delivery. The intrinsic muscles of the hand areinvolved, resulting in claw hand.

Injury to the Terminal BranchesMusculocutaneous NerveMusculocutaneous nerve injury results in paralysis of themuscles in the anterior compartment of the arm and there-fore weakening of elbow flexion and supination, as well asloss of sensation over the lateral forearm.

Radial NerveInjury to the radial nerve may result in “wrist drop” as aresult of the loss of wrist extensors and the unopposedactions of the flexor muscles.

Median nerveWhen the median nerve is compromised at the elbow, the2nd and 3rd digits remain partially extended on attemptingto make a fist—the “hand of the benediction.”

Ulnar NerveThe ulnar nerve may be compromised as it passes posteriorto the medial epicondyle, resulting in the characteristic“claw hand,” combined with sensory loss over the medialaspect of the palm.




Joints of the upper limb(Figure 6-3)

Joint Type Articulation Structure MovementsSternoclavicular

Acromioclavicular

Glenohumeral(shoulder)

Synovial Sternal end ofclavicle withmanubrium ofsternum and1st costalcartilage

Acromial endof claviclewithacromion ofscapula

Head ofhumerus withglenoid fossaof scapula;glenoid fossadeepened byglenoidlabrum

• Anterior, pos-terior, andinterclavicu-lar ligamentsstrengthenjoint

• Costoclavi-cular liga-mentattachesclavicle tosternum

• Divided into2 compart-ments by anarticular disk

• Coracoacro-mial andacromioclav-icular liga-mentsstrengthenjoint superi-orly

• Coracoclavi-cular liga-ment (subdi-vided intotrapezoidand conoid)strengthensjoint

• Glenohu-meral liga-mentsstrengthenjoint anteri-orly

• Coracohume-ral ligamentstrengthensjoint superi-orly

• Transversehumeral liga-ment forms

Protraction,retraction,elevation, anddepression

Rotation ofscapula onclaviclerelated tomovement ofthescapulotho-racic joint

Flexion,extension,abduction,adduction,medial rota-tion, lateralrotation, andcircumduction

(continued)



Joints of the upper limb (continued)


Scapulothoracic

Humeroulnar and humeroradial (elbow)

Proximal radioulnar joint

Distal radioulnar joint

Physio-logicjoint

Synovial

Thoracicwall withscapula andassociatedstructures

Trochlea andcapitulum ofhumerus withtrochlearnotch of theulna and thehead of the radius

Head ofradius withradial notchof ulna

Head of ulnawith ulnarnotch ofradius

canal for tendon of thelong head ofthe bicepsbrachii

• Most jointstrength fromrotator cuff(supraspina-tus, infra-spinatus, sub-scapularis,and teresminor)

• No bone tobone articu-lation

• Site ofscapula mov-ing on tho-racic wall

Radial andulnar collateralligamentsstrengthen thejoint on the lat-eral and medialaspects

Anular ligamentof the radiusholds the radialhead in radialnotch of ulna

Anterior andposterior liga-mentsstrengthen joint

Elevation,depression,protraction,retraction,and rotation

Flexion,extension

Supination,pronation byrotation ofthe radialhead

Supination,pronation bydistal radiusrotatingaround ulnarhead

(continued)



Joints of the upper limb (continued)

Joint Type Articulation Structure MovementsRadiocarpal (wrist)

Intercarpal

Carpometacarpal

Metacarpopha-langeal

Interphalangeal

Distal radiuswith proximalcarpal bones

Betweenadjacentcarpal bones

Carpals andmetacarpals

Head ofmetacarpalswithproximalphalanges

Heads ofproximalphalangesarticulatewith moredistalphalanges

• Anterior andposterior lig-amentsstrengthenjoint

• Ulnar collat-eralattaches tostyloidprocess ofulna and tri-quetrum

• Radial col-lateralattaches sty-loid ofradius andscaphoid

Anterior andposteriorinterosseousligaments sup-port joint

Palmarligaments,deeptransversemetacarpal,and collateralligaments sup-port joint

Palmar and col-lateralligaments sup-port joint

Flexion, exten-sion, abduc-tion, adduc-tion, andcircumduction

Gliding, flex-ion andabduction atmidcarpal

Flexion,extension,abduction,and adduc-tion

Flexion, exten-sion, abduc-tion, adduc-tion, andcircumduction

Flexion,extension


MnemonicElbow MovementsThree Bs Bend the elbow—

BrachialisBiceps brachiiBrachioradialis

Clinical SignificanceDislocationsDislocation of the acromioclavicular joint—a shoulderseparation, is relatively common in sports or falls thatimpact the shoulder.

Most dislocations of the glenohumeral joint occur infe-riorly because of the strong ligamentous and muscular sup-port elsewhere.

Subluxation and dislocation of the head of the radius—also known as “nursemaid’s elbow” or “pulled elbow”—iscommon in children that are suddenly lifted by the upper limb.


Ulna

Head ofradius

Radialtuberosity

Capitulum

Trochlea

Olecranonprocess

Humerus

FIGURE 6-7. Lateral elbow radiograph. (From Dudek RW, Louis




INTRODUCTIONThe head is that portion of the body that sits on the neck;the skeleton of the head is the cranium (skull), which con-tains the brain and meninges.

CRANIUM

Cranial bone summaryThe cranium is divided into a neurocranium and a viscero-cranium.

Neurocranium■ encases the brain■ roof—calvarium; floor—cranial base■ formed of bones: frontal, ethmoid, sphenoid, occipital,

temporal (2), and parietal (2)

Viscerocranium■ skeleton of the face■ formed of 15 bones: mandible, maxilla (2), inferior nasal

concha (2), nasal (2), lacrimal (2), vomer, ethmoid, zygo-matic (2), and palatine (2)

Bone Feature SignificanceZygoma- Prominence of Formed by union of temporal process of tic arch cheekbone zygomatic bone anteriorly and zygomatic

process of temporal bone posteriorly

Hard Bony anterior Formed by the palatine processes of the palate aspect of palate maxillae—anterior 2⁄3, and the horizontal

plates of the palatine bones—posterior 1⁄3

(continued)

196

7 Head


CHAPTER 7 | HEAD 197


Cranial bone summary (continued)

Frontal Overall • Forms anterior aspect of neurocranium• Skeleton of forehead• Forms roof of orbit and floor of anterior

cranial fossa

Supraorbital • Anterior superior aspect of orbitmargin • Possesses supraorbital foramen or notch—

transmits supraorbital neurovascular elements

Parietal Overall Form lateral aspects of neurocranium(2) Temporal lines (su- • Proximal attachment for temporalis and its

perior and inferior) investing fascia• Form superior border of temporal fossa

Groove for middle Conveys middle meningeal arterymeningeal artery

Occipital Overall Forms posterior aspect of neurocranium

External occipital Attachment for ligamentum nuchaeprotuberance

Nuchal lines (su- Superior—attachment for sternocleido-perior and inferior) mastoid, trapezius, and splenius capitis

Hypoglossal canal Transmits CN XII

Jugular foramen Shared foramen between occipital and temporal bones that transmits CN IX, X, and XI, and internal jugular vein and inferior petrosal sinus

Foramen magnum • Site of transition from medulla to spinal cord• Conveys CN XI and vertebral arteries into

cranial vault

Groove for trans- Location of transverse sinusesverse sinus

Internal occipital Location of the confluens of the sinusesprotuberance

Pharyngeal tubercle Attachment for pharyngeal raphe

Occipital condyles Articulation with atlas

Ethmoid Cribriform plate • Forms roof of nasal cavity• Transmits filia olfactoria—CN I

Perpendicular plate Forms superior aspect of nasal septum

Nasal conchae (su- • Form superior aspect of lateral walls of perior and middle) nasal cavity

• Act as turbinates for inspired air

Crista galli Attachment for falx cerebri

Sphenoid Lesser wing Forms superior border of superior orbital fissure

(continued)





Greater wing Forms inferior border of superior orbital fissure

Foramen ovale Conveys mandibular and lesser petrosal nerves

Foramen rotundum Conveys maxillary nerve

Foramen spinosum Conveys middle meningeal artery

Sphenopalatine Conveys sphenopalatine artery and foramen nasopalatine nerve to nasal cavity

Medial pterygoid Possesses hamulus that tensor palati wraps plate around on way to soft palate

Lateral pterygoid Attachment for medial and lateral pterygoid plate muscles

Optic canal Conveys CN II and ophthalmic artery

Sphenoid sinus Paranasal air sinus that empties into spheno-ethmoidal recess

Sella turcica • Forms hypophyseal fossa—location of hypophysis

• Anterior and posterior clinoid pro-cesses serve as attachments for dia-phragma sella and border the sella turcica, the dorsum sellae forms the posterior border of the hypophyseal fossa

Superior orbital • Space between lesser and greater wings fissure of the sphenoid

• Conveys CN III, IV, and VI, the ophthalmic nerve, and superior ophthalmic vein

Inferior orbital • Space between maxilla and greater wing fissure of sphenoid

• Conveys infraorbital nerve

Maxilla Zygomatic process Articulates with zygomatic bone to form anterior part of cheek

Infraorbital foramen Conveys infraorbital neurovascular elementsto face

Alveolar processes Form sockets for maxillary teeth

Infraorbital groove Conveys infraorbital neurovascular elements through orbit

Incisive canal Conveys septal branches of sphenopalatine artery and branches of the nasopalatine nerve

Palatine process Forms anterior 2⁄3 of bony palate

Nasal surface Forms anterior aspect of lateral wall of nasal cavity

Mandible Condylar process • Possesses a head and neck• Head articulates with temporal bone at

temporomandibular joint

(continued)



Bone Feature SignificanceCoronoid process Distal attachment for temporalis

Mandibular • Point along interior of ramus where inferior foramen alveolar neurovascular elements enter

mandible• Lingula borders entrance, serves as

attachment point for sphenomandibular ligament

Mental foramen Conveys mental neurovascular elements to chin region

Alveolar processes Form sockets for mandibular teeth

Mental spines (su- • Superior—proximal attachment for perior and inferior) genioglossus

• Inferior—proximal attachment for geniohyoid

Mylohyoid line Proximal attachment for mylohyoid

Ramus Vertical part between body (angle) and coronoid and condylar processes

Angle Bend between ramus and body

Body • Horizontal part, forms base of mandible• Possesses alveolar processes

Mandibular notch Notch between condylar and coronoid processes

Mental protuber- Anterior prominence that forms the chinance

Temporal Squamous part Flat, lateral aspect; forms part of neuro-(2) cranium

Petrous part • Thick, strong internal part• Houses vestibulocochlear apparatus

Groove for superior Location of superior petrosal sinuspetrosal sinus

Groove for sigmoid Location of sigmoid sinussinus

Hiatus for greater Conveys greater petrosal nerve into cranial petrosal nerve vault

Hiatus for lesser Conveys lesser petrosal nerve into cranial petrosal nerve vault

Internal acoustic Conveys CN VII and VII from cranial vault meatus into petrous part of temporal bone

External acoustic • Bony part of external earmeatus • Conveys sound to tympanic membrane

Zygomatic process Articulates with temporal process of zygomatic bone to form zygomatic arch


(continued)





Mandibular fossa Articulates with head of condylar process of mandible to form temporomandibular joint

Articular tubercle Bony prominence anterior to mandibular fossa that forms part of temporomandibular joint

Styloid process Proximal attachment for stylohyoid, stylo-pharyngeus, and styloglossus muscles andfor stylohyoid and stylomandibular ligaments

Mastoid process • Proximal attachment for posterior belly of digastric

• Distal attachment for sternocleidomastoid

Stylomastoid Exit for CN VII motor fibers from the craniumforamen

Petrotympanic Exit for chorda tympani from the craniumfissure

Carotid canal Canal conveying the internal carotid artery and its nerve plexus as they enter the cranium

Tympanic canali- Conveys tympanic nerve into middle ear culus cavity

Jugular foramen Shared foramen between occipital and temporal bones that transmits CN IX, X, and XI, and internal jugular vein and inferior petrosal sinus

Zygo- Zygomaticofacial Conveys sensory branches of zygomatic matic (2) and zygomatico- nerve to skin of cheek

temporal foramen

Temporal process Articulates with zygomatic process of temporal bone to form zygomatic arch

Inferior Overall • Forms inferior aspect of lateral walls of nasal nasal cavityconcha (2) • Acts as turbinate for inspired air

Palatine Perpendicular plate Forms posterior part of lateral wall of nasal (2) cavity

Horizontal plate Forms posterior 1⁄3 of hard palate

Palatine foramina Convey greater and lesser palatine neuro-(greater and lesser) vascular elements respectively

Nasal (2) Overall Form bridge of nose

Lacrimal Form part of medial wall of orbit(2)

Vomer Forms posteroinferior aspect of nasal septum



Clinical SignificanceFractures of the mandible usually occur in pairs, frequentlyon opposite sides.

The extraction of teeth leads to the resorption of alveolarbone. The mandible shrinks as a result, possibly leaving themental foramen open and the mental nerves exposed to painfrom dentures.

Additional ConceptThe cranial base is divided into three fossae for descriptivepurposes:

■ anterior cranial fossa—anterior to lesser wings of thesphenoid

■ middle cranial fossa—between lesser wings of the sphe-noid and the petrous ridge of the temporal bone

■ posterior cranial fossa—posterior to the petrous ridge ofthe temporal bone

ScalpThe scalp consists of the skin and fascia covering the bonesof the neurocranium.The first three layers form a single unitthat move together.

Layer Description Significance

Skin Thin Laden with hair follicles and sweat glands

Connective Thick Dense, highly innervatedtissue

Aponeurosis Connects frontal and occipi- Causes wrinkling of skin of tal bellies of occipitofrontalis forehead

Loose connec- Loose, with potential spaces • Allows scalp to movetive tissue freely

• Potential spaces may allowfor fluid accumulation

Pericranium Dense connective tissue Periosteum of neurocra-nium

Clinical SignificanceTraumaScalp wounds that do not lacerate the epicranial aponeuro-sis tend not to gape, owing to its strength.


MnemonicLayers of the Scalp

From superficial to deep, the layers of the scalp are:

SkinConnective tissueAponeurosisLoose connective tissuePericranium

BRAIN


Brain(Figure 7-1)

The brain is divided into the cerebrum, cerebellum andbrainstem.

■ surface area is increased by gyri and sulci■ fissures are deep gyri

Structure Description SignificanceCerebrum

Diencephalon

Cerebellum

Brainstem

• Largest part of brain• Formed of 2 cerebral

hemispheres and dien-cephalon

• Cerebrum divided intolobes

Located between cerebralhemispheres

Formed of 2 cerebellarhemispheres connectedby a midline vermis

Divided into midbrain,pons, and medulla

Lobes: frontal, parietal, temporal,and occipital

Divided into thalamus, hypothala-mus, epithalamus, and subthala-mus

Connected to pons of the brain-stem by cerebellar peduncles

• Midbrain—most rostral, givesrise to CN III and IV

• Pons—gives rise to CN V, VI,VII, and VIII

• Medulla—caudal-most, givesrise to CN IX, X, and XII

Clinical SignificanceConcussion and ContusionConcussion is a loss of consciousness after a head injury.Contusion results when the pia mater is stripped from thesurface of the brain, allowing blood to enter the subarach-noid space.


Cranial nerves(Figures 7-1, 7-3, and 7-7)

Structure Description SignificanceCN I

CN II

CN III

CN IV

CN V

CN VI

CN VII

CN VIII

CN IX

CN X

CN XI

CN XII

Olfactory

Optic

Oculomotor

Trochlear

Trigeminal

Abducens

Facial

Vestibulocochlear

Glossopharyngeal

Vagus

Spinal accessory

Hypoglossal

Conveys sense of smell from nasal cavity

Conveys visual information from retina

• Motor to levator palpebrae superioris,superior, medial and inferior rectus, andinferior oblique

• Parasympathetic to sphincter pupillae,ciliaris and superior tarsal muscles

Motor to superior oblique

Three divisions: 1. Ophthalmic (V1)—sensory to upper 1⁄3 of

face, cornea, and paranasal sinuses2. Maxillary (V2)—sensory to middle 1⁄3 of face,

upper teeth, maxillary sinuses, and palate3. Mandibular (V3)—sensory to lower 1⁄3 of

face, temporomandibular joint, anterior 2⁄3 of tongue, lower teeth, and motor tomuscles of mastication, anterior bellyof digastric, mylohyoid, tensor palati, andtensor tympani

Motor to lateral rectus

• Motor to muscles of facial expression,stapedius, stylohyoid, and posterior bellyof digastric

• Parasympathetic to submandibular,sublingual and lacrimal glands, and toglands of the nasal and oral mucosa

• Sensory to external acoustic meatus• Taste from anterior 2⁄3 of tongue

• Vestibular division—conveys balance andequilibrium information from inner ear

• Cochlear division—conveys auditoryinformation from inner ear

• Motor to stylopharyngeus• Parasympathetic to parotid gland• Sensory to parotid gland, pharynx, carotid

body and sinus, and middle ear• Taste and sensation from posterior 1⁄3 of

tongue

• Motor to pharynx, palate (except tensorpalati), and superior part of esophagus

• Parasympathetic to thorax and abdomen tomid-transverse colon

• Taste from palate and epiglottis• Sensory to external acoustic meatus

Motor to sternocleidomastoid and trapezius

Motor to muscles of tongue (exceptpalatoglossus)

203



Clinical SignificanceTrigeminal NerveTrigeminal neuralgia (tic douloureux) is a sensory disorderof the trigeminal nerve of unknown cause. The result isexcruciating pain over the face.

Facial NerveInjury to the facial nerve produces paralysis of the facialmusculature (Bell’s palsy) on the ipsilateral side, causing theface to droop.

MeningesThe meninges support and protect the brain and cranialnerve roots. They form the subarachnoid space for cere-brospinal fluid.

From superficial to deep, they are the:

■ dura mater■ arachnoid mater■ pia mater

Inferior view

Eyeball

Olfactory bulbOptic nerve (II)Olfactory tract (I)

Optic chiasmLateral olfactory stria

Trigeminal nerve (V):Ophthalmic nerve (V1)

Maxillary nerve (V2)Mandibularnerve (V3)

Trigeminalganglion

Pons

Abducensnerve (VI)

Facialnerve (VII)

Vestibulocochlearnerve (VIII)

Glossopharyngealnerve (IX)

Medullaoblongata

Optic tract

Oculomotornerve (III)

Trochlearnerve (IV)

Hypoglossalnerve (XII)

Vagusnerve (X)

Accessorynerve (XI)

Ventral root of1st spinal nerve

Spinal cord

FIGURE 7-1. Cranial nerves, inferior view. (Asset provided by




Structure Description SignificanceDura mater

Epidural space

Subdural space

Arachnoid mater

Arachnoid granulations

Subarachnoid space

Arachnoid trabeculae

Pia mater

Separates into 2 layers:periosteal and meningealin several areas—formingdural sinuses and duralfolds (meningeal layer)

Potential space betweencranium and dura mater

• Potential spacebetween the dura andarachnoid mater

• Filled with a looselyadhered cell layer

Middle meningeal layer

Evaginations of arachnoidthrough the dura into thesuperior sagittal sinus

Between arachnoid materand pia mater

Connective tissue strandsthat connect thearachnoid and pia mater

• Delicate inner layer incontact with thesurface of the brain

• Deep to thesubarachnoid space

• Tough, fibrous layer• Separated from cranium by

epidural space• Dural sinuses are blood-filled

channels between the periostealand meningeal layers of dura

• Meningeal dura is continuouswith the dura mater of thespinal cord

Site of epidural hematoma whentrauma causes bleeding into space

Site of subdural hematoma whentrauma causes bleeding intospace

Encloses the subarachnoid space

Convey cerebrospinal fluid fromsubarachnoid space into thesuperior sagittal sinus where itmixes with the venous blood

• Contains cerebrospinal fluid,arachnoid trabeculae, and vessels

• Irregular enlargements formcisterns

Span the subarachnoid space

Invests spinal blood vessels andthe roots of the spinal nerves

Clinical SignificanceVascular and Nerve SupplyThe dura mater receives its arterial supply primarily fromthe middle meningeal artery; the veins of the dura followthe arterial branches.The dura mater has rich sensory inner-vation primarily from the branches of CN V.

HeadacheStretching of the dura mater is a common cause of headaches,as it is sensitive to pain.

Meninges (continued)



Dural sinusesDural sinuses are found along the attached edge of duralfolds, most often between the periosteal and meningeal lay-ers of dura mater.

• Lies in superior, attached edge of cere-bral falx

• Receives CSF from arachnoidgranulations

• Lateral extensions—lateral lacunae alsoreceive CSF

• Conveys contents to confluens of thesinuses

Sinus Feature SignificanceSuperior sagittal

• Endothelial-lined venouschannels in theattached edgeof dural folds,between the layers of duramater

Additional Concept

(continued)

Dural foldsDural folds are formed where the dura mater separates intotwo layers: periosteal and meningeal.

Structure Feature SignificanceCerebral falx

Cerebellar falx

Cerebellar tentorium

Sellar diaphragm

• Lies in longitudinal fissure of brain• Separates cerebral hemispheres• Superior sagittal sinus lies in

attached edge, inferior sagittal sinuslies in inferior free edge; attaches tocerebellar tentorium

• Separates cerebellar hemispheres• Occipital sinus lies in attached edge

• Forms a roof over the cerebellum,separating it from the occipital lobeof the cerebrum

• Divides cranial cavity into supra- andinfratentorial compartments

• Anteromedial deficiency—tentorialincisure, allows passage of thebrainstem

• Straight sinus lies in edge attachedto cerebral falx

• Forms roof over hypophysial fossa• Stretches between clinoid processes• Central deficiency—allows

infundibulum to pass through• Cavernous and intercavernous

sinuses lie at edges

• Infolding ofmeningeal layerof dura mater asit reflects awayfrom periosteallayer

• Supports andprotects the brain

• Possess duralsinuses inmargins attachedto periosteallayer of dura



Dural sinuses (continued)

Sinus Feature Significance

Inferior sagittal

Straight

Confluence

Transverse

Sigmoid

Petrosal (superior and inferior)

Occipital

Cavernous

• Lies in the inferior, free edge of cerebralfalx

• Conveys contents to straight sinus

• Formed by union of inferior sagittal sinusand great cerebral vein

• Found in the attachment between thecerebral falx and cerebellar tentorium

• Receives blood from straight and supe-rior sagittal sinuses, conveys blood totransverse sinuses

• Located near the internal occipital protu-berance

Pass laterally from confluence of sinus,convey blood to sigmoid sinuses

• Continuation of transverse sinuses• Continuous with internal jugular vein at

jugular foramen

• Both drain cavernous sinus• Superior—located in anterolateral

attached edge of cerebellar tentorium,drains to junction of transverse and sig-moid sinuses

• Inferior—drains into internal jugularvein

• Located in attached edge of cerebellartentorium

• Drains blood to the confluence of thesinuses

• Located on either side of the sella tur-cica, associated with the sellardiaphragm

• Communicates with ophthalmic veinsand pterygoid plexus

• Drains posteriorly via petrosal veins• Walls of sinus contain V1, V2, CN III and

IV, sinus itself contains internal carotidartery and CN VI

• Right and left sinuses connected anteri-orly and posteriorly via intercavernoussinuses

• Receive cere-bral veins andconvey venousblood andcerebrospinalfluid (CSF) tothe internaljugular vein


Ventricular system of the brainThe ventricular system of the brain is both the source andpathway for the flow of cerebrospinal fluid (CSF). CSF acts asa buffer, waste depository, and shock absorber for the brain.

Structure Description SignificanceLateral (1st and 2nd) ventricles

3rd ventricle

4th ventricle

Subarachnoid space

Cerebrospinal (CSF) flowsthrough interventricularforamina into 3rd ventricle

CSF flows through cere-bral aqueduct into 4thventricle

CSF flows through amedian and 2 lateralapertures to enter sub-arachnoid space

CSF-filled space betweenthe arachnoid and piamater

• CSF is created by specializedtufts of pia mater—choroidplexus, located in each of the4 ventricles

• CSF is absorbed into the venoussystem through arachnoidgranulations—evaginations ofarachnoid mater into the supe-rior sagittal sinus

• Surrounds brain• Distended in areas to form

subarachnoid cisterns (e.g.,cerebellomedullary cistern (cis-terna magna)—between themedulla and cerebellum

Vasculature of the brain(Figure 7-2)

Clinical SignificanceCavernous SinusFractures of the cranial base may tear the internal carotidartery as it passes through the cavernous sinus, first causingcompression of CN VI and subsequently the structures inthe wall of the sinus.

Clinical SignificanceCSF may be obtained for diagnostic purposes by a lumbarpuncture, or in the case of an infant from the cerebel-lomedullary cistern via a cistern puncture. Excessive cere-brospinal fluid dilates the brain ventricles (hydrocephalus)and may cause thinning of the cerebral cortex and separa-tion of the bones of the calvaria in infants.

Origin: common carotid;enter skull through carotid

• Give rise to ophthalmic,anterior, and middle cerebrals

Vessel Origin/Termination Supplies/Gives Rise ToArteriesInternal carotid (2)

(continued)




Vasculature of the brain (continued)

Vessel Origin/Termination Supplies/Gives Rise To

Vertebral (2)

Anterior cerebral

Middle cerebral

Posterior cerebral

Basilar

Anterior communicating

Posterior communicating

Venous drainage is indirect, draining first to the dural sinuses, then to trueveins.

canal, and pass throughcavernous sinus

Origin: subclavian; passthrough transverseforamina of cervicalvertebrae and foramenmagnum to enter skull

Internal carotid

Basilar

Vertebral

Anterior cerebral

Posterior cerebral

• Primary supply to brain

• Give rise to basilar, posteriorinferior cerebellar, and anteriorspinal arteries

• Supply meninges, brain stem,and cerebellum

Supply medial aspect of cerebralhemispheres

Supply lateral aspect of cerebralhemispheres

Supply inferior aspect of cerebralhemispheres

• Gives rise to anterior inferiorcerebellar, labyrinthine,pontine, superior cerebellar,and posterior cerebral arteries

• Supply brainstem, cerebellum,and cerebrum

Forms part of cerebral arterialcircle

• Forms part of cerebral arterialcircle

• Supply cerebral peduncle,internal capsule, and thalamus

Additional ConceptThe cerebral arterial circle (of Willis), is located at the baseof the brain and is the anastomosis between the vertebrobasi-lar and internal carotid systems. It is formed by the posteriorcerebral, posterior communicating, internal carotid, anteriorcerebral, and anterior communicating arteries.

Clinical SignificanceStrokeAn artery supplying the brain can result in a stroke, cere-brovascular accident (CVA) and be evidenced by impairedneurologic function. Occlusion can occur by an embolus(clot) blocking arterial flow. Emboli can originate locally orat some distance (the heart).


FACE


Anteriorcerebral artery

Anteriorcommunicatingartery

Posteriorcommunicatingartery

Optic chiasm

Circle ofWillis

Infundibulum

Superiorcerebellar

artery

Pontinearteries

Anterior inferiorcerebellar

artery

Posteriorinferior

cerebellarartery

Labyrinthine(internal auditory)

artery

Posteriorspinalartery Anterior

spinalartery

Vertebralartery

Basilarartery

Posteriorcerebralartery

Middle cerebralartery

Internalcarotid artery

CNII

CNIII

CNVI

FIGURE 7-2. Circle of Willis. (From Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott Williams &

Wilkins; 2008:270.)

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsOccipito- Frontal— Frontal—skin Facial Elevates frontalis— epicranial of forehead eyebrows,frontal and aponeurosis Occipital— wrinkles skin occipital Occipital— epicranial of foreheadbellies superior nuchal aponeurosis

line

Muscles of the face(Figure 7-3)

(continued)




Muscles of the face (continued)

Orbicularis Margin of orbit, Skin around Closes palpe-oculi medial palpebral margin of bral fissure

ligament, and orbit and lacrimal bone tarsal plates

Corrugator Frontal bone Skin superior Wrinkles skin supercilii to orbit above nose by

drawing eye-brows medially

Procerus Nasal bone and Skin of Wrinkles skin of lateral nasal forehead nosecartilage

Nasalis Maxilla, nasal Alar cartilage, Flares nostrils, bone, and lateral skin of fore- wrinkles skin ofnasal cartilage head nose

Levator Maxilla Alar cartilage Flares nostrilslabii super-ioris alae-que nasii

Orbicularis Maxilla and Lips Closes mouth,oris mandible; skin protrudes lips

around mouth

Levator Maxilla Skin of upper Opens mouth; labii lip elevates uppersuperioris lip

Depressor Platysma, body Skin of lower Opens mouth;labii inferi- of mandible lip depresses oris angle of mouth

Buccinator Pterygomandi- Angle of Presses cheek bular raphe; mouth against teeth toalveolar pro- keep food out cesses of maxilla of oral vestibuleand mandible when chewing

Zygomati- Zygomatic bone Opens mouth; cus major elevates angle

Zygomati- Skin of upperof mouth

cus minor lip

Levator Infraorbital Angle ofanguli oris maxilla mouth

(continued)




Muscles of the face (continued)

Depressor Base of mandible Opens mouth; anguli oris depresses angle

of mouth

Risorius Fascia of parotid Opens mouthgland and skin of cheek

Platysma Skin of supra- Mandible, skin Depresses clavicular region of cheek and mandible,

mouth, orbicu- tenses skin of laris oris neck

Mentalis Body of Skin of chin Elevates skin of mandible chin; elevates

and protrudes lower lip

Supratrochlearnerve Procerus

Levator labiisuperiorisalaeque nasii

Levator labiisuperioris

Levatoranguli oris

Masseter

Mentalis

Mentalnerve

Depressoranguli oris

Parotidduct

Infraorbitalnerve

Zygomatico-facial nerve

Supraorbitalnerve

FIGURE 7-3. Anterior view of the face showing the cutaneous

branches of the trigeminal nerve, muscles of facial expression, and

eyelid (Image from Grant’s Atlas of Anatomy.)



Vasculature of the face(Figure 7-4)

Vessel Origin Supplies/Gives Rise ToArteriesFacial External carotid Face

Labial (superior Facial Lips and noseand inferior)

Lateral nasal Nose

Angular Nose and inferior eyelid

Superficial temporal External carotid Lateral aspect of face and temporal region

Transverse facial Superficial Face and parotid regiontemporal

Occipital External carotid Back of head

Posterior auricular Auricle and area posterior to auricle

Mental Inferior alveolar Chin

Supraorbital Ophthalmic Forehead and scalp

Supratrochlear

Venous drainage parallels arterial supply.

Lymphatics of the HeadLymphatic vessels from the head drain into deep cervicallymph nodes, which drain to the jugular lymphatic trunk.Collections of lymphatic tissue—tonsils, are found near theopening of the auditory tube—tubal tonsils, between theanterior and posterior pillars of the oral cavity—palatine ton-sils, on the posterior aspect of the tongue—lingual tonsilsand on the posterior aspect of the nasopharynx—pharyngealtonsils. Together these accumulations of lymphatic tissueform Waldeyer’s Ring.

Nerves of the face(Figure 7-3)

Nerve Origin Structures InnervatedSensoryBranches of the Ophthalmic NerveSupraorbital Frontal • Anterolateral scalp and forehead

• Frontal sinus• Upper eyelid

Supratrochlear • Anteromedial scalp and forehead• Upper eyelid

(continued)



Nerves of the face (continued)

Nerve Origin Structures InnervatedInfratrochlear Nasociliary • Medial aspect of both eyelids

• Lacrimal sac and caruncle• Lateral aspect of nose

Lacrimal Ophthalmic • Conveys parasympathetics to the lacrimal gland

• Conjunctiva and skin of upper eyelid

External nasal Anterior Majority of noseethmoidal—branch of nasociliary

Branches of the Maxillary NerveInfraorbital Maxillary • Cheek, upper lip, lower eyelid

• Maxillary sinus and teeth

Zygomaticofacial Zygomatic Cheek

Zygomaticotemporal Anterior aspect of temporal region

Branches of Mandibular NerveBuccal Mandibular • Cheek—skin and mucosa

• Buccal gingivae

Mental Inferior • Chinalveolar • Mucosa of lower lip

Auriculotemporal Mandibular—2 • Posterior aspect of temporal regionroots encircle • Anterior parts of ear, external auditorymiddle menin- meatus and tympanic membranegeal artery • Conveys secretomotor fibers to the

parotid gland from the otic ganglion

Branches from Cervical Spinal NervesGreat auricular Anterior rami— • Angle of mandible

C2 and C3 • Lobe of ear• Parotid sheath

Lesser occipital Scalp posterior to ear

Greater occipital Posterior Scalp of occipital regionramus—C2

3rd occipital Posterior Scalp of occipital and suboccipital ramus—C3 regions

MotorBranches of the Facial (CN VII) Muscles of facial expressionfacial nerve—temporal, zygomatic, buccal, mandibular, and cervical

Mandibular (V3) Trigeminal Muscles of mastication


Additional ConceptTrigeminal NerveBranches of the trigeminal nerve (CN V) provide mostsensory innervation of the face. The three divisions of thetrigeminal nerve are the ophthalmic (V1), maxillary (V2),and mandibular (V3) nerves.

TEMPORAL REGION



Temporal fossa • Bounded superiorly • Proximal attachment of and posteriorly temporalisby superior and • 4 bones forming pterion:inferior temporal lines frontal, parietal, temporal,of the parietal and greater wing of bones sphenoid

• Floor formed by 4bones that make up the pterion

Infratemporal • Bounded laterally by the Contains:fossa zygomatic arch and • Part of temporalis

mandible • Medial and lateral • Medial border: lateral pterygoid muscles

pterygoid plate • Pterygoid plexus of veins• Found posterior to the • Maxillary artery

maxilla • Branches of mandibular nerve

Temporal region structure

Additional ConceptThe temporal region includes the temporal—superior tothe zygomatic arch and infratemporal fossae—inferior tothe zygomatic arch.

Clinical SignificanceMandibular NerveA needle is passed through the mandibular notch of the mandible into the infratemporal fossa to anesthe-tize the mandibular nerve as it emerges from the cranial cavity.



Vasculature of the temporal region

Vessel Origin Supplies/Gives Rise ToArteries

Maxillary External carotid Supplies structures of the temporal region

Deep auricular Maxillary— Supplies external auditory meatus1st part

Anterior tympanic Supplies tympanic membrane

Middle meningeal Supplies dura mater

Inferior alveolar • Supplies mandible, floor of mouth, gingivae, and mandibular teeth

• Gives rise to mental—supplies chin

Deep temporal Maxillary— Supplies temporalis2nd part

Muscular Supply masseter, buccinator and cheek,(masseteric, and the medial and lateral pterygoidsbuccal and ptery-goid branches)

Posterior superior Maxillary— Supplies posterior maxillary teeth and alveolar 3rd part gingivae

Infraorbital • Supplies lower eyelid, lacrimal sac, upper lip, and infraorbital region of face

• Gives rise to anterior superior alveolar—supplies anterior maxillary teeth and gingivae

Descending Supplies palate and gingivaepalatine

Pharyngeal Supplies superior aspect of pharynx

Sphenopalatine Supplies lateral nasal wall and septum

Vessel Termination DrainsVeins

Pterygoid venous Facial and Structures in the infratemporal fossaplexus maxillary veins

Venous drainage generally parallels arterial supply in the temporal region.

Additional ConceptThe maxillary artery is divided into 3 parts by its relationto the lateral pterygoid muscle.



Nerves of the temporal region

Nerve Origin Structures InnervatedMandibular (V3) Trigeminal • Sensory to structures in the temporal

region• Branches convey parasympathetic fibers• Motor to muscles of mastication

Buccal Mandibular • Cheek—skin and mucosa• Buccal gingivae

Auriculotemporal • Posterior aspect of temporal region• Anterior parts of ear, external audi-

tory meatus, and tympanic membrane• Conveys secretomotor fibers to the

parotid gland from the otic ganglion

Inferior alveolar • Forms inferior dental plexus that innervates mandibular teeth

• Emerges from mental foramen as mental nerve

Lingual • Anterior 2⁄3 of tongue and lingual gingivae

• Conveys secretomotor fibers to the submandibular ganglion and subman-dibular and sublingual glands

• Conveys special sense of taste from anterior 2⁄3 of tongue to chorda tympani

Nerve to mylohyoid Inferior alveolar Mylohyoid

Chorda tympani Facial • Receives taste fibers from anterior 2⁄3 of tongue from lingual nerve

• Conveys presynaptic parasympathe-tics from CN VII to lingual nerve

Otic ganglion Innervated by Postsynaptic fibers ride on the auriculo-inferior saliva- temporal nerve to innervate the parotidtory nucleus gland

PTERYGOPALATINE FOSSA

Pterygopalatine fossaThe pterygopalatine fossa is a small, inverted rain dropshaped fossa, which is positioned for access to multiple areasof the head for distribution of neurovascular elements.

Structure Description SignificanceOverall Borders: Openings and communications:

• Superior—greater wing • Superior/anterior—orbitof sphenoid through inferior orbital fissure

(continued)



Structure Description Significance• Anterior—maxilla • Inferior/posterior—middle• Inferior—pyramidal cranial fossa through foramen

process of palatine rotundum• Medial—perpendicular • Medial—nasal cavity through

plate of palatine sphenopalatine foramen• Lateral—continuous with • Lateral—infratemporal fossa

infratemporal fossa through pterygomaxillary fissure

Contents Maxillary nerve • Enters fossa via foramen rotundum

• Gives off zygomatic nerve in fossa—conveys postsynaptic parasympathetic fibers from pterygopalatine ganglion to lacrimal nerve—to lacrimal gland

• Gives off pterygopalatine nerves that suspend ptery-gopalatine ganglion—convey general sense through gang-lion to branches of V2—supply nasal and oral cavities

• Leaves fossa via infraorbital fissure and changes name to infraorbital nerve

Pterygopalatine ganglion • Parasympathetic ganglion• Presynaptic innervation is from

superior salivatory nucleus via the greater petrosal nerve— a branch of CN VII

• Greater petrosal joins the deep petrosal—sympathetic, to form the nerve of the ptery-goid canal

• Autonomics leave ganglion toinnervate lacrimal, nasal, and oral cavity glands

Maxillary artery • Enters fossa via pterygo-maxillary fissure

• Gives rise to following branchesin fossa:1. Posterior superior alveolar2. Descending palatine3. Sphenopalatine4. Infraorbital—gives rise to

anterior superior alveolar ininfraorbital canal

Pterygopalatine fossa (continued)


ORAL REGION


Oral region(Figure 7-4)

The oral region includes the oral cavity, which extends tothe palate superiorly and the palatopharyngeal fold posteri-orly, tongue, teeth, and gingivae (gums). The oral cavityreceives ingested substances, begins digestion, and forms abolus that can be swallowed.

Structure Description SignificanceOral vestibule

Oral cavity proper

Gingivae (gums)

Teeth

Space between the teethand gingivae and the lips

Space contained withinsuperior and inferior dentalarches—formed of themaxillary and mandibularalveolar processes thatcontain the teeth

• Mucous membranecovered fibrous tissue

• Adherent to alveolarprocesses and necks ofteeth

• Hard, enamel-covered• Set in alveolar

processes of maxillaand mandible

• Possess crown, root,and neck

• 32 total in adult: 6molars, 4 premolars, 2canine, and 4 incisorsin each dental arch

• Oral fissure—space betweenupper and lower lips, sizevaries by orbicularis oris andlabial muscles

• Lips—muscular foldssurrounding oral fissure; upperlip sensory by V2, lower by V3;philtrum—vertical groove inupper lip

• Cheeks—contain buccinatormuscles that function to keepfood out of oral vestibulebetween the occlusal surfacesof teeth

• Continuous posteriorly with theoropharynx

• Space occupied by the tongue

• Mandibular gingivae innervatedby buccal and lingual nerves

• Maxillary gingivae innervatedby greater palatine,nasopalatine, and superioralveolar nerves—anterior,middle, and posterior

• Used in mastication• 20 deciduous teeth in children• Maxillary teeth innervated by

superior dental plexus, formedby branches of V2

• Mandibular teeth innervated byinferior dental plexus, formedby branches of V3

(continued)



Oral region (continued)

Structure Description SignificanceTongue

Palate

Temporo-mandibular joint

• Muscular organ, mostlycontained within oralcavity proper

• Divided into right andleft halves by midlinegroove

• Possesses:• Root—posterior 1⁄3• Body—anterior 2⁄3• Apex—tip• Dorsum—site of

lingual papillae:vallate, foliate,filiform and fungiform

• Inferior surface—haslingual frenulum

• Forms roof of oralcavity and floor of nasalcavities

• Hard palate—bonyanterior portion, formedby palatine processesof maxilla andhorizontal plates ofpalatine bones

• Soft palate—moveableposterior portion ofpalate; anterior part—composed of palatineaponeurosis, posteriorpart—muscular

• Synovial joint

• Functions in mastication,deglutition, articulation andtaste

• V-shaped groove on dorsum—terminal groove dividestongue into anterior 2⁄3 andposterior 1⁄3 parts, center ofgroove possesses small pit—foramen cecum that was theopening of the thyroglossalduct in the embryo

• Vallate, foliate, and fungiformpapillae have taste buds

• Lingual frenulum connectstongue to floor of mouth

• Innervation:• Motor—hypoglossal to all

muscles exceptpalatoglossus: pharyngealplexus

• Sensory to anterior 2⁄3:general sense—lingual,taste—chorda tympani

• Posterior 1⁄3: general senseand taste—glossopharyngeal

• Blood supply: lingual artery,veins parallel arteries

• Hard palate has 3 foramina:1. Incisive fossa: conveys

nasopalatine nerve toanterior aspect of hard palate

2. Greater palatine foramen:conveys greater palatinevessels and nerves toposterior aspect of hard palate

3. Lesser palatine foramen:conveys lesser palatine vesselsand nerves to soft palate

• Soft palate: uvula assists inclosing oropharynx fromnasopharynx during swallowing

• Articular disk with anterior andposterior bands divides thejoint cavity into 2 separatecompartments

(continued)




Structure Description Significance• Between head of

mandible withmandibular fossa andarticular tubercle of thetemporal bone

• Joint supported by a stronglateral ligament—athickening of the joint capsuleand by 2 extrinsic ligaments:(1) stylomandibularligament and (2) spheno-mandibular ligament

• Movements: elevation,depression, protrusion,retrusion, and side-to-sidegrinding movements

Frontal sinus

Hypophysial fossa

Sphenoid sinus

Pharyngeal tonsil

Auditory tube

Palatoglossalarch

Palatopharyngealarch

Palatine tonsil

Epiglottis

Vocal fold

Ventricle

Vestibular fold

Mandible

Geniohyoid

Genioglossus

Hardpalate

Nasalconchae

FIGURE 7-4. Nasopharynx, oropharynx, and laryngopharynx.

(From Moore KL, Agur AMR. Essential Clinical Anatomy. 3rd ed.


Clinical SignificanceTemporomandibular JointThe temporomandibular joint may become arthritic, lead-ing to problems with dental occlusion and joint clicking(crepitus).


Deep Lingual VeinsThe deep lingual veins on the inferior surface of the tongueprovide a rapid entry for drugs, such as nitroglycerin fortreatment of angina pectoris.

Tongue TiedAn overlarge lingual frenulum (tongue tie) interferes withtongue movement and speech. Frenectomy may be per-formed to free the tongue.


Salivary glandsThere are three pairs of salivary glands:

■ parotid■ submandibular■ sublingual

All glands received secretomotor fibers from the parasym-pathetic nervous system. They function to produce saliva,which binds ingested foot into a bolus and begin the diges-tive process.

Gland Description SignificanceParotid

Submandibular

Sublingual

• Possesses tough fascialsheath—parotid sheath

• Located anteroinferior toexternal auditory meatus

• Parotid duct passesanteriorly to conveysecretions into the oralcavity near the 2nd maxillarymolar

• Located deep to body ofmandible

• Submandibular ductpasses anteriorly to conveysecretions into the oralcavity on the surface ofsublingual papilla—located on either side of thelingual frenulum

• Located between themandible and genioglossusmuscle in floor of mouth

• Convey secretions into oralcavity via multiplesublingual ducts

• Parasympatheticinnervation from cells inotic ganglion reachtarget viaauriculotemporal nerve

• Sympathetic innervationfrom carotid plexusinhibit secretion

• Sensory innervation viaauriculotemporal nerve

• Parasympatheticinnervation from cells inthe submandibularganglion reach targetvia the lingual nerve

• Sympathetic innervationfrom carotid plexusinhibit secretion


Clinical SignificanceSialographyIn a sialography, contrast is injected into the submandibularduct to reveal the duct and some of the secretory units of thegland.


Muscles of mastication

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsTemporalis

Masseter

Medial pterygoid

Lateral pterygoid

Temporal fossa

Zygomatic arch

Medial surfaceof lateralpterygoid plate

Lateral surfaceof lateralpterygoid plate

Coronoidprocess ofmandible

Lateral aspectof angle andramus ofmandible

Medial aspectof angle andramus ofmandible

Disk oftemporomandibular joint andcondyloidprocess ofmandible

Mandibular Elevate andretract mandible

Elevatemandible

Elevatemandible,produces side-to-side grindingmotion

Protrudesmandible, side-to-side grindingmotion

Extrinsic muscles of the tongue(Figure 7-4)

Extrinsic Proximal Distal Main Muscle Attachment Attachment Innervation ActionsGenioglossus

Hyoglossus

Superiormentalspine ofmandible

Hyoid bone

Dorsum oftongue andhyoid

Lateral aspectof tongue

Hypoglossal Depresses,protrudes andmoves tonguefrom side toside

Depresses andretrudes tongue

Additional ConceptThe masseter and medial pterygoid essentially form asling attached to the angle of the mandible that elevates themandible.

(continued)


Additional ConceptThe intrinsic muscles of the tongue—superior and infe-rior longitudinal, transverse, and vertical—have no bonyattachments and function to alter the shape of the tongue;they are all innervated by the hypoglossal nerve. Theextrinsic muscles of the tongue alter the position of thetongue.


Muscles of the tongue (continued)

Extrinsic Proximal Distal Main Muscle Attachment Attachment Innervation ActionsStyloglossus

Palatoglossus

Styloidprocess

Palatineaponeurosis

Dorsum oftongue

Pharyngealplexus

Retrudestongue,elevates sides

Draws softpalate andtongue together

Muscles of the palate

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsTensor palati

Levator palati

Palatoglos-sus

Palatopha-ryngeus

Musculus uvulae

Scaphoid fossabetween medialand lateralpterygoid plates

Cartilage ofauditory tube

Palatineaponeurosis

Palatineaponeurosis

Tongue

Pharynx

Uvula

Mandibular(V3)

Pharyngealplexus

• Tenses softpalate andopens audi-tory tubeduring swal-lowing

• Changesdirection ofpull by wrap-ping aroundhamulus ofmedial ptery-goid plate

Elevates softpalate

Draws softpalate andtongue together

Tenses softpalate, elevatespharynx

Elevates uvula



Additional ConceptThe palatoglossus and palatopharyngeus are covered bymucosa and are often referred to as the anterior and poste-rior pillars in dentistry. Between them lies the tonsillar fossafor the palatine tonsil.

NOSE AND EAR

Nose(Figure 7-4)

The nasal apparatus includes the external nose, nasal cavi-ties, and paranasal air sinuses. It functions in olfaction, res-piration, filtration and humidification of inspired air.

Structure Description SignificanceExternal nose

Nasal cavities

• Composed of a dorsum(bridge) and apex (tip)

• Nares (nostrils)—arebounded laterally by thealae of the nose andmedially separated by thenasal septum; open intothe nasal cavities

• Possesses bony andcartilaginous parts

• Mucosal-lined cavitiesseparated by nasalseptum

• Superior 1⁄3 isolfactory—containsolfactory receptor cells

• Inferior 2⁄3 is respira-tory

• Arterial supply:sphenopalatine,ethmoidal (anterior andposterior), greater pala-tine, superior labial,and branches of thefacial arteries

• Veins parallel the arteries• Sensory innervation is

via nasopalatine,greater palatine, andanterior ethmoidalnerves

• Bony skeleton:• Nasal bones• Frontal bone—nasal part

and nasal spine• Nasal septum• Maxillae—frontal process

• Cartilaginous skeleton:• Lateral cartilages (2)• Alar cartilages (2)• Septal cartilage

• Nasal septum composed of:perpendicular plate of ethmoid,vomer, and septal cartilage

• Lateral walls possesssuperior, middle, andinferior nasal conchae—actas turbinates

• Spaces inferior to conchae—superior, middle, andinferior meatuses

• Space superior to superiorconcha is sphenoethmoidalrecess

• The nasal cavities arecontinuous with thenasopharynx posteriorly at thechoanae

(continued)


Clinical SignificanceBloody NoseKiesselbach’s area is an area on the anterior aspect of thenasal septum where all five arteries supplying the nasal cav-ity anastomose. It is an area from which may come profusebleeding.

Deviated SeptumThe nasal septum is usually deviated to one side or theother, either naturally or as a result of trauma. Deviation canbe corrected if it is severe and interferes with breathing orexacerbates snoring.

Additional ConceptThe meatuses and sphenoethmoidal recess are spacesthat communicate with sinuses where structures empty intothe nasal cavity:

■ sphenoethmoidal recess: sphenoid sinus■ superior meatus: posterior ethmoid air cells■ middle meatus: middle ethmoid air cells onto the ethmoid

bulla—an expanded ethmoid air cell in the meatus; ante-rior ethmoid air cell and maxillary sinus into the semilu-nar hiatus—a depression surrounding the ethmoid bulla;frontal sinus via frontonasal duct into the infundibulum—leads to the semilunar hiatus

■ inferior meatus: nasolacrimal duct

Ear(Figure 7-5)

The ear is divided into external, middle, and inner parts.The external and middle ear transfer sound to the inner ear.


Nose (continued)

Structure Description SignificanceParanasal sinuses

Extensions of the nasalcavity into the surround-ing bones:• Frontal• Ethmoidal—divided

into anterior, middle,and posterior air cells

• Sphenoidal• Maxillary

Function as resonant chambersfor the voice and in lightening theskull


The inner ear contains the organs of hearing and equilib-rium.


Part Description SignificanceExternal

Middle

Inner

• Composed of auricleand external auditorymeatus—bony carti-laginous S-shaped tube

• Innervated primarily byauriculotemporal andgreat auricular nerves

• Arterial supply: poste-rior auricular andsuperficial temporalarteries

• Veins parallel arteries

• Air-filled chamberbetween the tympanicmembrane and inner ear

• Connected to nasophar-ynx by auditory tubeand mastoid air cellsthrough aditus

• Contains malleus,incus, and stapes

• Stapedius and tensortympani connect tostapes and malleus,respectively

• Chorda tympani trav-els through middle earcavity

• Spiraling series of peri-lymph-containing chan-nels through the petrouspart of temporal bone—bony labyrinth containsendolymph-filled mem-branous labyrinth

• Organs of membranouslabyrinth: saccule, utri-cle, semicircular canals(3), and cochlea

• Cochlea is innervatedby the cochlear divisionof CN VIII

• Saccule, utricle, andsemicircular canals areinnervated by thevestibular division ofCN VIII

• Auricle funnels sound into externalauditory meatus

• External auditory meatus:• Ends at tympanic membrane

(eardrum)—border betweenexternal and middle ear

• Filled with hairs and cerumen (wax)

• Auditory tube equalizes middle earpressure with atmospheric pressurefor optimal hearing

• Tympanic membrane vibrations aretransferred along the malleus, incusand stapes—the movement of thestapes in the oval window transfersthe vibration to the inner ear

• Stapedius and tensor tympanidampen sound—innervation:stapedius—CN VII, tensor tympani—CN V

• Saccule and utricle: located investibule of bony labyrinth; containmacula—receptor organ thatresponds to changes in head position

• Semicircular canals: 3 on eachside, contain crista ampullari—receptor organs that respond tohead acceleration

• Cochlea: transduces vibrations ofstapes in oval window to excitationof CN VIII using organ of Corti—receptor organ of membranouslabyrinth for hearing


Clinical SignificanceEar InfectionOtitis media, an infection of the middle ear cavity, can besecondary to an upper respiratory tract infection. Thebulging, red tympanic membrane may perforate as a resultof pressure from infection or trauma.

ORBIT

Orbit structure(Figures 7-3 and 7-6)

The orbits are a pair of bony, pyramidal-shaped cavities inthe face that contain:

■ eye■ extraocular muscles■ lacrimal apparatus■ neurovascular elements


Auricle

Incus

Malleus

StapesSemicircularcanals

VestibularnerveCochlearnerveVestibulocochlearnerve

Pharyngotympanictube

Tympanic membrane

Parotid gland

Externalacousticmeatus

Opening ofexternalacousticmeatus

Internal acousticmeatus

Auriculotemporalnerve

Anterior view

Cochlea

FIGURE 7-5. Anatomy of ear. (From Dudek RW, Louis TM.

High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott Williams &

Wilkins; 2008:302.)



Structure Description SignificanceOrbit

Palpebrae (eyelids)

Eye

Bony walls:

• Superior—orbital partof frontal and lesserwing of sphenoid

• Inferior—maxilla andzygomatic and palatine

• Medial—ethmoid andfrontal, lacrimal andsphenoid

• Lateral—frontal processof zygomatic and greaterwing of sphenoid

Apex: optic canalBase: orbital margin

• Outer surface—thin skin• Inner surface—palpe-

bral conjunctiva• Middle—orbicularis

oculi and tarsal plates:superior and inferiorand tarsal glands

• Medial and lateralpalpebral ligamentsattach tarsal plates toorbit

• Eyelashes and ciliaryglands

• Lacrimal puncta openon summit of lacrimalpapilla on the upperand lower eyelids

• Orbital septum—anextension of periosteumthat connects to thetarsal plates

• 3 layers of eyeball:1. Outer—fibrous:

sclera and cornea

2. Middle—vascular:choroid, ciliary bodycomposed of ciliarisand ciliary processesand iris that containsdilator pupillae andsphincter pupillae

• Superior wall contains fossafor lacrimal gland

• Medial wall contains lacrimalgroove and fossa for lacrimalsac

• Inferior wall is separated fromlateral by inferior orbital fissure,which conveys the continuationof the maxillary nerve

• Optic canal conveys the opticnerve (CN II)

• Overall: the eyelids protect andmoisten the eye, sweepinglacrimal secretions inferomedi-ally toward medial canthus ofeye

• Tarsal plates strengthen eye-lids and act as skeleton; thesuperior tarsal muscle attachesto superior tarsal plate

• Tarsal glands associated withtarsal plates secrete lipids toprevent eyelids from stickingtogether and leaking oflacrimal fluid

• Palpebral ligaments provideattachment for orbicularis oculi

• Orbital septum helps stop thespread of infection and main-tains the orbital fat in place

• Outer layer: sclera—white,opaque posterior 5⁄6, fibrousskeleton of eye; cornea—anterior 1⁄6, transparent, avas-cular part of refractive media

• Middle layer: choroid—con-tains blood vessels; ciliarybody—contraction of ciliarisby CN III parasympatheticsproduces accommodation,ciliary processes secrete

Orbit structure (continued)

(continued)


Additional ConceptConjunctivaThe conjunctiva is a mucous membrane that is looselyadherent to the sclera, known as bulbar conjunctiva, whereit is invested with blood vessels and on the inner surface ofthe eyelids as palpebral conjunctiva. At the medial can-thus of the eye—the junction of the upper and lower eyelidson the medial side, the remnant of a human nictitatingmembrane is evident as a semilunar fold of conjunctiva.Thesemilunar fold lines the lacrimal lake, at the center ofwhich is an elevation, the lacrimal caruncle that functions



Lacrimal apparatus

3. Inner—retina:divided into outerpigmented layer andinner neural layer

• Spaces within eyeballdivided into 3 parts:1. Anterior chamber—

between cornea andiris

2. Posterior chamber—between iris and lens

3. Vitreous body—fillsarea posterior to lens

• Lens—flexible avascularpart of refractive mediaof eye; surrounded bylens capsule that istensed by suspensoryligaments

• Lacrimal glands—located in the fossa forthe lacrimal gland

• Lacrimal ducts—empty into superiorfornix

• Lacrimal canaliculiconvey tears to thelacrimal sac via capil-lary action

aqueous humor and viasuspensory ligaments hold thelens; iris—continually variesin size to alter size of pupil,dilator under sympathetic con-trol, and sphincter underparasympathetic control (CN III)

• Inner layer: retina inner neurallayer contains photoreceptorsand the ganglion cells that formCN II, ends anteriorly at oraserrata; area of highest visualacuity—macula lutea the cen-ter of which has a small pit—fovea centralis, located at thecenter of the visual axis; opticdisk is a blind spot medial tomacula lutea where CN IIleaves the eye and the centralartery of the retina enters

• Lacrimal glands—producelacrimal secretions (tears);secretomotor from facial nerveparasympathetics, sympathet-ics inhibit production

• Lacrimal ducts—conveylacrimal secretions to conjunc-tival sac

• Lacrimal sac is the dilatedproximal end of thenasolacrimal duct that con-veys lacrimal secretions to theinferior nasal meatus

Orbit structure (continued)



to push the lacrimal secretions to the edge of the lake so thatthey can be removed by lacrimal canaliculi. The lines ofreflection between bulbar and palpebral conjunctiva are thesuperior and inferior fornices. The conjunctiva line a sac,the conjunctival sac the opening of which is the palpebralfissure—the space between the upper and lower eyelids. Itis into this sac that contact lenses are inserted and eyedropsdeposited and into the superior fornix of the sac wherelacrimal secretions are emptied via excretory ducts.

Clinical SignificanceBlowout FractureA blow to the orbit is most likely to fracture the relativelythin inferior and medial walls, leading to a blowout fracturewith the stronger bony margin intact.

ExophthalmosTumors within the orbit or deposition of retrobulbar fat (asin Grave’s disease) produce exophthalmos or protrusion ofthe eye.

Optic discMacula

Branches of retinal vessels

FIGURE 7-6. Retina. (From Dudek RW, Louis TM. High-Yield GrossAnatomy.3rd ed. Baltimore: Lippincott Williams & Wilkins; 2008:298.)


Additional ConceptSuperior Tarsal MuscleThe anterior-most fibers of levator palpebrae superiorisare smooth muscle—the superior tarsal muscle. Thissmooth muscle component is primarily responsible forkeeping the upper eyelid raised.


Extraocular muscles(Figures 7-7 and 7-8)

Proximal Distal Main Muscle Attachment Attachment Innervation ActionsLevator palpebrae superioris

Superior rectus

Inferior rectus

Medial rectus

Lateral rectus

Superior oblique

Inferior oblique

Lesser wing ofsphenoid

Common tendi-nous ring

Sphenoid

Anterior aspectof floor of orbit

Superior tarsalplate, skin ofupper eyelid

Anterior hemi-sphere ofsclera

Passes anteri-orly throughtrochlea,changes direc-tion andattaches toposteriorhemisphere ofsclera

Posteriorhemisphere ofsclera

Oculomotorand sympa-thetics—superiortarsal muscle

Oculomotor

Abducens

Trochlear

Oculomotor

Elevate uppereyelid

Elevates,adducts, andmediallyrotates eye

Depresses,adducts, andlaterally rotateseye

Adducts eye

Abducts eye

Depresses,abducts, andmediallyrotates eye

Elevates,abducts, andlaterally rotateseye

ConjunctivitisThe conjunctiva is colorless except when its vessels aredilated (bloodshot eyes) or inflamed from infection (con-junctivitis, or pinkeye).



Abduction

IO

LR

SO

IO

LR

SO

SR

MR

IR

SR

MR

IR

AdductionAbduction

AbductionAdduction

Depre

ssio

nE

levation

Depre

ssio

nE

levation

Abduction

FIGURE 7-8. Eye movements. Large arrows indicate the direction

of eye movements caused by the various extraocular muscles. Small

arrows indicate either intorsion (medial rotation of the superior pole

of the eyeball) or extorsion (lateral rotation of the superior pole of

the eyeball). IO � inferior oblique, LR � lateral rectus, SO � supe-

rior oblique, MR � medial rectus, IR � inferior rectus. (From

Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore:


Oculomotor nerve(CN III)

Trochlearnerve

(CN IV)

Pons

Abducentnerve

(CN VI)

Trigeminalganglion(CN V)

Lateralrectus

Medialrectus

Ciliaryganglion

Levator palpebraesuperioris

Superiorrectus

Inferioroblique

Inferiorrectus

Superior oblique

Superior orbital fissureTendinous ring

Optic nerve in sheath transversing optic canal

FIGURE 7-7. Innervation of muscles of eyeball.The oculomotor (CN

III), trochlear (CN IV), and abducent (CN VI) nerves are distributed

to the muscles of the eyeball. The nerves enter the orbit through the

superior orbital fissure. CN IV supplies the superior oblique, CN VI

supplies the lateral rectus, and CN III supplies the remaining five mus-

cles. (From Moore KL, Dalley AF. Clinically Oriented Anatomy. 5th ed.



Clinical SignificanceEye MovementsThe medial walls of the orbits are parallel; therefore, the axisof the eye is not in line with the axis of the orbit. The rectimuscles attach via a common tendinous ring at the apex ofthe orbit and so produce unwanted movements of the eyewhen they contract—adduction and rotation. The superiorand inferior oblique muscles offset the rotation and adduc-tion of the eye by the recti to get a more straightforward ele-vation or depression.

Fascial Sheath of the EyeballThe eye is surrounded by the fascial sheath of the eyeball,which forms a “socket” into which the eyeball sits and thatis attached to and pierced by the extraocular muscles.Extensions of the sheath are attached to the orbit as medialand lateral check ligaments that limit adduction andabduction of the eye. The check ligaments blend with thefascia of the inferior rectus and inferior oblique muscles toform the suspensory ligament of the eyeball, a hammock-like sling that supports the eye.The fascial sheath of the eye-ball forms the socket into which a prosthetic eye is inserted,still allowing for relatively natural movement because of theconnection to the extraocular muscles.

MnemonicTo recall the innervation pattern of the extraocular musclesuse this “formula”:

[SO4LR6]3 Superior Oblique by CN IV; Lateral Rectus byCN VI and all the rest by CN III.


Vasculature of the orbit

Supplies structures of orbit, face,and scalp

Supplies retina

Supplies forehead and scalp

Supplies nose

Internal carotid

Ophthalmic

Vessel Origin Supplies/Gives Rise ToArteriesOphthalmic

Central artery of the retina

Supraorbital

Supratrochlear

Dorsal nasal

(continued)


Vasculature of the orbit (continued)

Vorticose vein

Ophthalmic veins

Cavernous sinus orinferior ophthalmicvein

Cavernous sinus andthe inferiorophthalmic alsodrains into the ptery-goid venous plexus

Supplies eyelids, conjunctiva, andlacrimal gland

Supplies ethmoidal air cells andnasal cavity

Supplies middle layer of eye

Aqueous humor from anteriorchamber

Middle layer of eye

Retina

Eye and orbit

Nerves of the orbit(Figure 7-7)

Nerve Origin Structures InnervatedFrontal

Nasociliary

Ethmoidal (anterior and posterior)

Long ciliary

Short ciliary

Lacrimal

Ciliary ganglion

Ophthalmic

Ophthalmic

Nasociliary

Ciliary ganglion

Ophthalmic

Innervated byaccessory oculo-motor nucleus

Upper eyelid, scalp, and forehead via twoterminal branches—supraorbital andsupratrochlear

Eye, face, and nasal cavity

Sphenoid and ethmoid air cells andnasal cavity

• Eye• Conveys sympathetics to iris and sen-

sation from cornea

• Eye• Conveys sympathetics and parasympa-

thetics from CN III to iris and ciliaris

• Conveys parasympathetics to thelacrimal gland from V2

• Conjunctiva and skin of upper eyelid

• Presynaptic parasympathetics are con-veyed via CN III

• Postganglionics are conveyed viashort ciliary nerves to ciliaris andsphincter pupillae

235

Vessel Origin Supplies/Gives Rise ToLacrimal

Ethmoidal (anterior and posterior)

Posterior ciliary (short and long)

Anterior ciliary

Vessel Termination DrainsVeinsScleral venous sinus

Vorticose

Central vein of the retina

Superior ophthalmic

Inferior ophthalmic


PARASYMPATHETIC GANGLIA IN THE HEAD


Parasympathetic ganglia in the head

Ganglia Afferents EfferentsCiliary

Otic

Pterygopalatine

Submandibular

Accessory oculomotornucleus via CN III

Inferior salivatory nucleusvia CN IX

Superior salivatorynucleus via CN VIIbranch—greater petrosalnerve

Superior salivatorynucleus via CN VIIbranch—chorda tympani

Postsynaptics innervate sphincterpupillae and ciliaris

Postsynaptics innervate parotidgland

Postsynaptics innervate oral andnasal mucosa and the lacrimalgland

Postsynaptics innervate the sub-lingual and submandibular glands

MnemonicThe acronym C-O-P-S is a useful way to remember the fourparasympathetic ganglia of the head.


INTRODUCTIONThe neck supports the head and connects it to the trunk.It not only houses organs of its own, but serves as a pas-sageway for structures coursing between the head andtrunk.

NECKSkeleton of the Neck The skeleton of the neck consists of the seven cervical ver-tebrae—presented with the back, the sternum—presentedwith the thorax, the clavicles—presented with the upperlimb and the hyoid bone.

The hyoid bone does not articulate with any other bones.It functions primarily as a muscle attachment for muscles ofthe tongue and larynx.

Clinical SignificanceHyoid FractureFractures of the hyoid are common in persons who arestrangled. The result is an inability to elevate the hyoid,which makes swallowing and the prevention of ingested sub-stances from entering the airway difficult.

Fascia and spaces of the neck(Figure 8-1)

The neck is surrounded by a fatty layer of superficial fas-cia; the deep fascia of the neck divides it into compart-ments, facilitates movement, and determines the spread ofinfection.

8Neck

237



• Overlies the deep cervical fascia• Contains the platysma• Contains neurovascular, lymphatic,

and fat

• Surrounds entire neck like a sleeve• Splits to enclose the sternocleidomastoid

and trapezius muscles and submandibular and parotid gland—forms fibrous capsule

• Continuous with nuchal ligament

• Encloses the vertebral column, longus coli,scalenes—anterior, middle and posterior, longuscapitis, and deep cervical muscles

• An extension of prevertebral fascia forms theaxillary sheath—that surrounds the axillaryvessels and brachial plexus

• Encloses the infrahyoid muscles, thyroid gland,trachea, and esophagus

• Continuous with buccopharyngeal fascia

• Encloses the common carotid artery, internaljugular vein, and vagus nerve

• Composed of contributions from investing,prevertebral and pretracheal fascia

• Encloses the pharynx• Continuous with pretracheal fascia

• Between prevertebral and buccopharyngeal fascia

• Subdivided by alar fascia• Permits movement of the viscera during

swallowing • Also called—danger space, because it is a

pathway for infection to spread between theneck and posterior mediastinum

Fascia and spaces of the neck (continued)

Structure Description

Superficial cervical fascia

Deep Cervical Fascia

Investing

Prevertebral

Pretracheal

Carotid sheath

Buccopharyngeal fascia

Spaces of the Neck

Retropharyngeal space


CHAPTER 8 | NECK 239

FIGURE 8-1. Sections of head and neck demonstrating cervical

fascia. (From Moore KL, Dalley AF. Clinically Oriented Anatomy.5th ed. Baltimore: Lippincott Williams & Wilkins; 2006:1050.)

Pharynx

Mandible

Hyoid

Investing fascia

Larynx

Trachea

Manubriumof sternum Esophagus

Medial view

Occipitalbone

Body of vertebra

Intervertebral disc

Anterior longitudinalligament

Longus colli muscle

Prevertebral fascia

Retropharyngeal space

Buccopharyngeal fascia

Pharyngeal muscle

Pharynx

Superficial cervicalfascia (subcutaneous

tissue)

Pretrachealfascia



Region Description and ContentsAnterior cervical • Borders:(anterior triangle of • Anterior—midline of neckthe neck) • Posterior—anterior border of sternocleido-

mastoid• Inferior—junction of midline of neck and

sternocleidomastoid• Superior—mandible• Roof—investing layer of deep cervical fascia• Floor—pretracheal fascia investing pharynx,

larynx, and thyroid

• Nerves in region:• Transverse cervical—sensory to skin of region• Hypoglossal—supplies tongue• Vagus• Glossopharyngeal

• Arteries in region:• Common carotid—terminate in region to

form internal and external carotidarteries

• Internal carotid—no branches in neck; enter cranium via carotid canal

• External carotid—terminates as maxillary and superficial temporal arteries; before termina-tion gives:1. Ascending pharyngeal2. Occipital3. Posterior auricular4. Superior thyroid5. Lingual6. Facial

• Veins in region:• Internal jugular—begins at jugular foramen as

continuation of sigmoid sinus, joins subclavian to form brachiocephalic vein, receives—inferiorpetrosal sinus, facial, lingual, pharyngeal, and thyroid veins—superior and middle

• Anterior jugular• Subdivided by digastric and omohyoid into:

• Submental triangle—unpaired; between anterior bellies of digastrics, mandibular symphysis and hyoid; contains—submental nodes

Regions of the neck (Figures 8-2, 8-3, and 8-6)

The neck is divided into four regions.

(continued)



Region Description and Contents• Submandibular triangle—between mandible

and anterior and posterior bellies of digastric; contains—submandibular gland and nodes, hypoglossal nerve (CN XII), facial artery, and vein

• Carotid triangle—between superior belly of omohyoid, posterior belly of digastric, and anterior border of sternocleidomastoid; contains—common carotid artery and branches,vagus, spinal accessory and hypoglossal nerves, cervical plexus, thyroid gland, larynx, pharynx, and cervical nodes

• Muscular triangle—between superior belly of omohyoid, anterior border of sternocleido-mastoid, and midline of neck; contains—infrahyoid muscles, thyroid, and parathyroid glands

Lateral cervical • Borders:(posterior triangle of • Anterior—posterior border of sternocleido-the neck) mastoid

• Posterior—anterior border of trapezius• Inferior—clavicle• Superior—junction of sternocleidomastoid

and trapezius• Roof—investing layer of deep cervical

fascia• Floor—prevertebral layer of deep cervical

fascia that covers the middle and posterior scalenes, levator scapulae, and splenius capitis

• Nerves in region:• Spinal accessory (CN XI), supplies sternocleido-

mastoid and trapezius• Brachial plexus—roots and trunks, supplies

upper limb• Suprascapular nerve—supplies supra- and

infraspinatus• Cervical plexus—C1–C4: give rise to phrenic

nerve (C3–C5) that supplies the diaphragm, ansa cervicalis that supplies infrahyoid muscles,and cutaneous branches: lesser occipital, greatauricular, transverse cervical, and supra-clavicular, emerge from nerve point of the neck—a quarter-sized area midway along the posterior border of sternocleidomastoid

Regions of the neck (continued)

(continued)


Additional ConceptSubclavian ArteryThe subclavian artery passes posterior to the anterior sca-lene, whereas the vein passes anterior.

Carotid ArteryIn the carotid triangle, the common carotid artery dividesinto internal and external carotid arteries. At the bifurca-tion is the carotid sinus—a dilation of the internal carotidthat functions as a baroreceptor—measures blood pres-sure, innervated by CN IX. The carotid body also liesnear the bifurcation and functions as a chemoreceptor—measures oxygen levels in blood, it is also innervated byCN IX.

Clinical SignificanceExternal Jugular VeinThe external jugular vein may become prominent and evi-dent throughout its course as a result of increased venouspressure as occurs in heart failure.


Region Description and Contents• Arteries in region:

• Transverse cervical—from thyrocervical trunk• Suprascapular—from thyrocervical trunk• Occipital—from external carotid artery• Subclavian—3rd part, supplies upper limb

• Veins in the region:• External jugular—formed by junction of

retromandibular and posterior auricular veins, terminates in subclavian

• Subclavian—drains upper limb, joins internal jugular to form brachiocephalic vein

• Subdivided by inferior belly of omohyoid into:• Occipital triangle—superior to omohyoid• Omoclavicular triangle—inferior to

omohyoid

Posterior cervical • Located posterior to anterior border of trapezius

• Contains trapezius, suboccipital triangle—lies deep

Regions of the neck (continued)



Maxillary

Facial

Lingual

Superiorthyroid

Superficialtemporal

Occipital

Internalcarotid

Carotidsinus

FIGURE 8-2. Lateral arteriogram (digital subtraction) of the head

and neck region with a blocked internal carotid artery. The most

common location of atherosclerosis in the carotid artery is at the

bifurcation of the common carotid artery. Carotid artery plaques

are usually ulcerated plaques. (From Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd ed. Baltimore: Lippincott Williams &

Wilkins; 2008:268.)



Muscles of the neck (Figures 8-3 and 8-6)

Proximal DistalMuscle Attachment Attachment Innervation Main ActionsSternocle- Manubrium and Mastoid pro- Spinal Laterally flexes idomastoid clavicle cess and sup- accessory and extends

erior nuchal neck; rotates line head

Suprahyoids—Superior to the Hyoid

Mylohyoid Mylohyoid line Mylohyoid ra- Nerve to Elevates hyoidof mandible phe and hyoid mylohyoid (V3)

Digastric Anterior belly— Intermediate Anterior Depresses mandible; post- tendon at- belly—nerve mandible,erior belly— tached tohyoid to mylohyoid elevates hyoidtemporal bone by connective (V3); posterior

tissue belly—facial

Geniohyoid Inferior mental Hyoid C1 via Elevates hyoidspine of hypoglossal mandible

Stylohyoid Styloid process Facial

Infrahyoids—Inferior to the Hyoid

Omohyoid Scapula Hyoid Ansa cervicalis Depresses

Sterno- Sternum Thyroid hyoid

thyroid cartilage

Sterno- Hyoidhyoid

Thyrohyoid Thyroid cartilage C1 via hypo-glossal

PrevertebralLongus coli C1–C6 vertebrae C3–T3 Anterior rami Flexes and

vertebrae of C2–C6 rotates neck

Longus Occipital bone C3–C6 Anterior rami Flexes headcapitis vertebrae of C1–C3

Rectus C1 vertebra Anterior rami capitis of C1–C2(anterior and lateral)

Anterior C4–C6 1st rib Anterior ramiscalene vertebrae cervical

Middle spinal nerves Laterally flexes scalene neck

Posterior 2nd ribscalene


The trapezius is described with the shoulder region of the upperlimb.The platysma is described with the muscles of the face.

Additional ConceptInnervationThe ansa cervicalis is a loop in the cervical plexus consist-ing of fibers from the first three cervical nerves. Fibers fromC1–C2 form the superior root, whereas fibers from C2–C3form the inferior root that unite to form the ansa cervicalis.

Clinical SignificanceTorticollisTorticollis is a contraction of the cervical muscles, mostcommonly the sternocleidomastoid, which produces a twist-ing of the neck and slanting of the head.

Root of the neckThe root of the neck is the area of junction between the infe-rior aspect of the neck and the superior aspect of the thorax.


Feature Description SignificanceNerves • Vagus • Vagus—located in carotid sheath; right

• Right recurrent recurrent laryngeal arises after right vagus laryngeal passes over subclavian artery, left recurrent

• Left recurrent laryngeal arises after left vagus nerve laryngeal passes over arch of aorta; recurrent

• Phrenic laryngeals ascend in tracheoesophageal • Sympathetic groove to supply trachea, esophagus

trunks and larynx• Phrenic—C3–C5; sensory and motor to

diaphragm• Sympathetic trunks—3 ganglia: superior,

middle, and inferior; postsynaptics conveyed via gray communicating branches to cervical spinal nerves, cardiopulmonary splanchnic nerves to thoracic viscera, and the periarterial plexus to head and neck viscera

Arteries • Brachiocephalic • Brachiocephalic trunk terminates by dividing trunk into right common carotid and right

• Subclavian— subclavian arteriesright and left • Right subclavian is a branch of brachio-

cephalic trunk; left is a branch of the arch of the aorta

Veins • External jugular • External jugular drains scalp and face; • Anterior jugular empties into subclavian• Subclavian

(continued)



Feature Description Significance• Anterior jugular formed by submandibular

veins, unites with contralateral counterpart to form the jugular venous arch superior to sternum; empties into external jugular

• Subclavian vein begins as axillary vein crosses 1st rib; ends by joining internal jugular vein to form brachiocephalic at the venous angle—place where thoracic duct and right lymphatic duct typically join venous system on left and right sides respectively

Root of the neck (continued)

Hypoglossus

Genioglossus

Geniohyoid

Thyrohyoid

Omohyoid

Sternohyoid

Sternothyroid

Styloglossus

Inferior rootSuperior root

Ansacervicalis

Internal carotidartery

C1Nerve roots

of cervicalplexus

Hypoglossalnerve (CN XII)

Hypoglossal nerve(CN XII)

C2

C3

Lateral view

FIGURE 8-3. Distribution of hypoglossal nerve (CN XII). CN XII

leaves the cranium through the hypoglossal canal and passes deep

to the mandible to enter the tongue, where it supplies all intrinsic

and extrinsic lingual muscles, except the palatoglossus. CN XII is

joined immediately distal to the hypoglossal canal by a branch

conveying fibers from the C1 and C2 loop of the cervical plexus.

These fibers hitch a ride with CN XII, leaving it as the superior root

of the ansa cervicalis and the nerve to the thyrohyoid muscle.

(From Moore KL, Dalley AF. Clinically Oriented Anatomy. 5th ed.



Additional ConceptSubclavian ArteriesThe subclavian arteries are divided into three parts by theanterior scalene muscle. Part 1 is proximal, Part 2 is deep,and Part 3 is distal to the muscle.

Part 1 branches—

■ vertebral—runs superiorly in transverse cervical foramina,enters cranium through foramen magnum to supply brain

■ internal thoracic—supplies structures in thorax■ thyrocervical—gives rise to inferior thyroid artery: to neck

viscera, suprascapular: to scapular region, transverse cer-vical: to lateral cervical region, and ascending cervical: toneck musculature

Part 2 branches—

■ costocervical trunk—gives rise to superior intercostal: tofirst two intercostal spaces and deep cervical: to neckmusculature

Part 3 branches—

■ dorsal scapular—supplies rhomboids and levator scapulaeand the scapular region

Sympathetic TrunksThe inferior cervical and first thoracic sympathetic gangliaoften fuse to form the cervicothoracic or stellate ganglion.

MnemonicPhrenic NerveNerve roots in the phrenic nerve: C3, C4, and C5 keep thediaphragm alive.

Clinical SignificanceSubclavian VeinThe subclavian vein is a common point of entry for centralline placement.

Lymphatics of the neckSuperficial lymphatic drainage of the neck is to superficialcervical lymph nodes located along the external jugularvein. Superficial drainage and drainage from deep struc-tures is conveyed to deep cervical lymph nodes, generally



found along the internal jugular vein. Efferents from thedeep cervical nodes form the jugular lymphatic trunksthat empty lymph into the right lymphatic or thoracicduct.


Structure Description DrainageThyroid Lymphatic vessels comm- The network of vessels drain

unicate in a network around to prelaryngeal, pretracheal,the fibrous capsule of the and paratracheal nodes, gland which drain into deep cervical

nodes

Parathyroid Lymphatic vessels drain Parathyroid vessels drain glands into deep cervical and para-

tracheal nodes

Larynx Lymphatic vessels accom- • Vessels superior to vocal pany laryngeal arteries folds follow superior la-

ryngeal artery to the deep cervical nodes

• Vessels inferior to vocal folds drain into pretracheal or paratracheal nodes, which drain to deep cervical nodes

Pharynx Lymphatic vessels from The lymph from the tonsils is the tonsils drain to nodes referred to the jugulo-near the angle of the digastric nodemandible

Additional ConceptTonsillar RingThe palatine, lingual, tubal, and pharyngeal tonsils form thetonsillar ring (Waldeyer’s Ring)—a ring of lymphatic tissuearound the superior aspect of the pharynx.

Clinical SignificanceTonsillectomyTonsillectomy is performed by removing the palatine ton-sil and its fascia from the tonsillar bed. Inflammation ofthe pharyngeal tonsils is adenoiditis. Inflamed adenoidsmay interfere with nasal breathing and allow infection to spread to the middle ear cavity through the auditorytube.


ENDOCRINE ORGANS IN THE NECK

Thyroid and parathyroid(Figures 8-2 and 8-6)

The endocrine organs of the neck include the thyroid andparathyroid glands. The thyroid gland—located in the ante-rior aspect of the neck, produces thyroid hormone and cal-citonin, whereas the four parathyroid glands—embedded inthe posterior aspect of the thyroid gland—produce parathy-roid hormone.


Gland Feature DescriptionThyroid • Lobes—right and left are • Gland is surrounded by a

connected by an isthmus fibrous capsule and the • Arterial supply—superior pretracheal layer of deep

and inferior thyroid cervical fasciaarteries • Superior and middle thyroid

• Venous drainage— veins drain into the internalsuperior, middle and jugular veins, whereas theinferior thyroid veins inferior veins drain the

• Innervation—sympathetic brachiocephalic veins• Sympathetic innervation is

from the cervical sympa-thetic ganglia; the post-ganglionics follow arteries to the gland and cause vasoconstriction

Parathyroid • Arterial supply—inferior Sympathetic innervation is thyroid glands from the cervical sympathetic

• Venous drainage—drain ganglia; the postganglionicsinto the thyroid veins follow arteries to the gland

• Innervation—sympathetic and cause vasoconstriction

Additional ConceptThyroid Ima ArteryThe thyroid ima artery is present in approximately 10% ofpeople. It has a variable origin, often from the aorta, and, whenpresent, supplies the trachea and isthmus of the thyroid. Thismidline artery must be considered during procedures in themidline of the neck.

Clinical SignificanceGoiterEnlargement of the thyroid gland—goiter, results fromiodine deficiency. The enlarged gland may compress nearbystructures.


RESPIRATORY STRUCTURES IN THE NECK

Larynx and trachea(Figures 8-2, 8-4, and 8-5)

The larynx routes air into the respiratory tract, food into theesophagus, blocks the airway during swallowing, and pro-duces the voice.

The trachea, presented in detail in the thorax chapter(see Chapter 1), extends from the inferior border of thecricoid cartilage of the larynx to its termination in the tho-rax at the level of the sternal angle as the right and left pri-mary bronchi.


Epiglottis

Vestibular foldVocal fold

Aryepiglottic fold

Rima glottidis

FIGURE 8-4. Laryngeal cartilages. Photograph depicting the struc-

tures observed during inspection of the vocal cords using a laryngeal

mirror. (From Dudek RW, Louis TM. High-Yield Gross Anatomy. 3rd


Structure Description SignificanceLaryngeal inlet Space bounded by aryepi- Entrance into the larynx at

glottic folds and epiglottis which point the vestibule ofthe larynx is continuous withthe laryngopharynx

Laryngeal Space bounded by laryngeal Space contained between vestibule inlet superiorly and vesti- the quadrangular membrane

bular folds inferiorly

(continued)


Additional ConceptBlood Supply to the LarynxThe superior laryngeal artery, a branch of the superior thy-roid artery, passes through the thyrohyoid membrane withthe internal laryngeal nerve to anastomose with the internallaryngeal artery, a branch of the inferior thyroid artery thataccompanies the inferior laryngeal nerve. The venousdrainage parallels arterial supply.

Clinical SignificanceValsalva ManeuverIn the Valsalva maneuver, the vestibular and vocal folds aretightly adducted after a deep inspiration. Contraction of theabdominal muscles increases intrathoracic and intraabdom-inal pressures, thereby impeding venous return to the heart.



Laryngeal Lateral extension of laryngeal Laryngeal saccule—blind-ventricle cavity between vestibular ended, mucous-secreting poc-

and vocal folds ket that opens into ventricle

Infraglottic Space bounded by vocal Continuous inferiorly with cavity folds superiorly and inferior lumen of trachea

border of cricoid cartilage inferiorly

Vestibular folds Mucosa covered folds that • Contain vestibular ligamentproject into laryngeal cavity • Space between—rima

vestibuli• Adducting vestibular folds

prevents ingested sub-stances from entering airway

Vocal folds • Contain vocal ligament and vocalis: lateral to vocal ligaments, involved in whispering

• Adducting vocal folds prevents ingested sub-ances from entering airway

Glottis Vocal folds and space bet- Varying the tension and ween them—rima glottidis length of the vocal folds

varies size of rima glottidis to produce varying pitch for speech

Larynx and trachea (continued)


Skeleton of the larynx(Figure 8-5)

The skeleton of the larynx consists of nine cartilages that areconnected by membranes and ligaments.


Structure Description SignificanceThyroid cartilage Composed of 2 laminae— • The anterior junction of

possess a set of superior the laminae form theand inferior horns on their laryngeal prominenceposterior borders or Adam’s apple

• The superior horn and border of the cartilage attach to the hyoid by the thyrohyoid membrane

• The inferior horns articu-late with the cricoid car-tilage at the cricothyroid joint

Cricoid cartilage Complete cartilaginous ring • Connected to thyroid inferior to thyroid cartilage cartilage by median

cricothyroid ligament• Connected to 1st tracheal

ring by cricotracheal ligament

Epiglottic Mucous covered, leaf- • Inferior aspect attached tocartilage shaped anterior border of thyroid by thyroepiglottic

the laryngeal inlet ligament• Anterior aspect attached

to hyoid by hypoepi-glottic ligament

Arytenoid • 3 sided, pyramidal-shaped: • Apex: articulates with cartilages (2) 1. Apex corniculate cartilages and

2. Vocal process is embedded within the 3. Muscular process aryepiglottic fold

• Articulate with cricoid • Vocal process: posteriorcartilage at cricoaryte- attachment for vocalnoid joints ligament

• Muscular process: attach-ment for lateral and posterior cricoarytenoid muscles

Corniculate • Articulate with apex of Provide structure to aryepi-cartilages (2) arytenoid cartilages glottic folds

• Embedded within aryepi-glottic fold

Cuneiform Embedded within aryepi-cartilages (2) glottic fold

(continued)


Clinical SignificanceFractureLaryngeal fractures are common. They may produce hemor-rhage and edema, obstruction of the airway, and hoarseness.

Muscles of the larynxThe extrinsic muscles of the larynx include the supra- andinfrahyoid musculature described with the muscles of theneck and are involved in moving the larynx as a whole—suprahyoids elevate the larynx; infrahyoids depress the larynx.


Thyrohyoid Attaches thyroid cartilage • Midline thickening is membrane to hyoid median thyrohyoid

ligament• Lateral thickenings form

lateral thyrohyoid ligaments

Vocal ligament Extend from laryngeal • Thickened, free superior prominence anteriorly to border of conus elasticusvocal process of arytenoid • Covered by mucosa tocartilages posteriorly form vocal fold

Quadrangular Extends from arytenoid • Free inferior border—membrane cartilages to sides of vestibular ligament,

epiglottic cartilages covered by mucosa to form vestibular fold

• Free superior border—aryepiglottic ligament,covered by mucosa to form aryepiglottic fold

Conus elasticus • Superior border—vocal • Continuous anteriorly with ligaments median cricothyroid

• Lateral extensions— ligamentlateral cricothyroid • Close tracheal inlet whenligaments vocal ligaments are

approximated

JointsCricothyroid Articulation between inferior Movements: rotation and

horns of thyroid and cricoid gliding of thyroid on the cartilage cricoid

Cricoarytenoid Articulation between Movements: sliding of arytenoid cartilages and arytenoid cartilages—toward cricoid cartilage or away from each other,

tilting and rotation of arytenoids


Skeleton of the larynx (continued)


The intrinsic muscles of the larynx move the skeleton ofthe larynx to alter tension on the vocal folds and the size ofthe rima glottidis.


Epiglottis

1st

2nd

3rdRight lateral view

Lamina

Arch Cricoid

cartilage

Inferior

horn

Oblique line

Superior

horn Thyroid

cartilage

Greater horn

of hyoid

Tracheal cartilages

Lesser horn of hyoid

Body of hyoid

Thyrohyoid

membrane

Laryngeal

prominence

Median

cricothyroid

ligament

Cricotracheal

ligament

FIGURE 8-5. Skeleton of larynx, right lateral view. (From Moore KL,

Dalley AF. Clinically Oriented Anatomy. 5th ed. Baltimore: Lippincott


Proximal DistalMuscle Attachment Attachment Innervation Main ActionsVocalis Arytenoid Vocal Inferior Alter tension

cartilage ligament laryngeal on vocalligament for whispering

Cricothyroid Cricoid cartilage Thyroid External Tenses vocal cartilage laryngeal ligament

(continued)


Additional ConceptInnervationAll intrinsic laryngeal musculature is innervated by branchesof CN X. The external and internal laryngeal nerves arebranches of the superior laryngeal nerve, which is a branchof CN X. The internal laryngeal nerves supplies sensoryinnervation superior to the vocal folds, whereas the externallaryngeal nerves supplies the cricothyroid muscle. Sensoryinnervation inferior to the vocal folds and all of the remain-ing intrinsic musculature is supplied by the recurrent laryn-geal nerve, via the inferior laryngeal branch.

ALIMENTARY STRUCTURES IN THE NECK

Pharynx and esophagus(Figure 8-1)

The pharynx is the fibromuscular tube that serves as a com-mon route for air and ingested substances. It extends fromthe base of the cranium to the inferior border of the cricoidcartilage of the larynx. It is divided into three parts based onwhat region/structure it lies posterior to and communicateswith: (1) nasopharynx, (2) oropharynx, and (3) laryngophar-ynx. The esophagus, presented in the thorax chapter (seeChapter 1), extends from the pharyngoesophageal junction


Proximal DistalMuscle Attachment Attachment Innervation Main ActionsThyroary- Thyroid cartilage Arytenoid Inferior Relaxes vocal tenoid cartilage laryngeal ligament

Lateral Cricoid Adducts vocalcricoary- cartilage foldstenoid

Posterior Abducts vocal cricoary foldstenoid

Transverse Arytenoid Contralateral Alter tension on and oblique cartilage arytenoid vocal ligamentarytenoids cartilage

Muscles of the larynx (continued)


to its termination in the abdomen at the cardial orifice of thestomach. It is composed of voluntary, skeletal muscle in itsupper third, a mixture of skeletal and smooth muscle in itsmiddle third, and involuntary, smooth muscle as its inferiorthird. The innervation mirrors the musculature—the supe-rior half receives somatic motor and sensory innervation,whereas the inferior half receives autonomic (vagal parasym-pathetic and sympathetic) and visceral sensory innervation.


Structure Description SignificanceNasopharynx • Posterior to nasal cavity • Communicates with nasal

• Extends inferiorly to level cavity via posterior of soft palate choanae

• Pharyngeal tonsils— • Pharyngeal tonsils—located on posterior wall aggregate of lymphatic

• Auditory tube—opens tissueon posterolateral wall • Auditory tube (pharyngo-

• Salpingopharyngeal tympanic tube)—openingfold—extends from torus surrounded by cartilaginoustubaris to blends with torus tubaris and lympha-pharyngeal muscles tic elements—the tubal

tonsil• Salpingopharyngeus

underlies the mucosal that forms the fold; its contrac-tion opens the auditory tube during swallowing

Oropharynx • Posterior to oral cavity • Receives bolus of food • Between soft palate and from oral cavity during

epiglottis swallowing• Palatine tonsils— • Palatine tonsils (tonsils)—

located between palato- aggregate of lymphatic glossal and palatopha- tissue that lie in the ryngeal arches tonsillar bed: formed by

the superior constrictor and pharyngobasilar fascia—that fascia that fills space between the superior constrictor and the cranium

Laryngopharynx • Posterior to larynx • Walls formed by middle • Between epiglottis and and inferior constrictor,

cricoid cartilage palatopharyngeus, and • Communicates anteriorly stylopharyngeus muscles

with larynx at laryngeal • Piriform recess—inlet depression on each side of

laryngeal inlet between pharyngeal wall and aryepiglottic fold


Additional ConceptSwallowingSwallowing has three phases:

1. Stage 1: voluntary; food is formed into bolus and pushedinto oropharynx

2. Stage 2: involuntary; soft palate elevates, pharynx widensand shortens

3. Stage 3: involuntary; pharyngeal constrictors force foodinferiorly into esophagus

Blood Supply to the PharynxThe longitudinally oriented pharynx receives branches froma host of arteries throughout its course, including tonsillar,ascending and descending palatine, lingual, and ascendingpharyngeal arteries.Venous drainage parallels arterial supply.

Clinical SignificancePiriform FossaThe superior laryngeal artery and internal and inferiorlaryngeal nerves lie just deep to the mucosa of the piriformfossa and are subject to damage when ingested objectsbecome lodged here.

Muscles of the pharynx (Figures 8-3 and 8-6)

The muscles of the pharynx are arranged into an externalcircular layer and an internal longitudinal layer. All laryngealmuscles are voluntary.


Proximal DistalMuscle Attachment Attachment Innervation Main ActionsExternalSuperior Pterygomandi- Pharyngeal Pharyngeal Constricts constrictor bular raphe, tubercle of plexus pharynx

mandible, occipital bone tongue, pterygoid and pharyn-hamulus geal raphe

Middle Stylohyoid Pharyngeal constrictor ligament and raphe

hyoid bone

Inferior Thyroid and constrictor cricoid cartilage

(continued)


Additional ConceptFascia of the PharynxThe fascia covering the internal aspect of the pharyngealconstrictors is pharyngobasilar fascia, whereas the fasciaon their external surface is buccopharyngeal fascia. Thepharyngobasilar fascia combines with the buccopharyngeal


Proximal DistalMuscle Attachment Attachment Innervation Main ActionsInternalPalato- Palatine Pharynx Pharyngeal Tenses soft pharyngeus aponeurosis plexus palate, elevates

pharynx

Stylo- Styloid process CN IX Elevatespharyngeus of temporal bone pharynx

Salpingo- Torus tubaris of Pharyngeal pharyngeus of auditory tube plexus

Digastric,posterior belly

Glossopharyngealnerve (CN IX)Internal jugular veinInternal carotid artery

Styloid processStylohyoid

Esophagus

Right recurrentlaryngeal nerve

Inferior thyroid artery

Thyroid gland

Inferior constrictor

Pharyngeal raphe

Middle constrictor

Stylopharyngeus

Pharyngeal plexus

Cricopharyngeal part ofinferior constrictor

PharyngobasilarfasciaSuperior constrictor

CN XI

CN IX

CN XII

Posterior view

Left recurrentlaryngeal nerve

Vagus nerve (CN X)

Sympathetic trunkand plexus

Common carotid artery

Superior laryngeal nerve

Superior cervicalsympathetic ganglion

Hypoglossal nerve (CN XII)

Spinal accessorynerve (CN XI)

Sternocleidomastoid

Sensory ganglion ofvagus nerve

(CN X)

FIGURE 8-6. Pharynx and cranial nerves, posterior view. (From

Moore KL, Dalley AF. Clinically Oriented Anatomy. 5th ed.


Muscles of the pharynx (continued)



fascia superior to the superior constrictor to fill the gapbetween the superior constrictor and the cranium.

InnervationThe musculature of the pharynx, with the exception of thestylopharyngeus, is supplied by the pharyngeal plexus.Motor fibers in the pharyngeal plexus are from CN X,whereas sensory fibers are from CN IX. The superior-most part of the nasopharynx receives sensory innervationfrom V2.

Constrictor MusclesThe constrictors are arranged like a stack of nested flowerpots, with gaps between each. The gaps allow structures toenter and leave the pharynx. The four gaps between:

1. superior constrictor and cranium—conveys levator palati,auditory tube, and ascending palatine artery

2. superior and middle constrictors—conveys stylopharyn-geus, stylohyoid ligament, and the glossopharyngealnerve

3. middle and inferior constrictors—conveys internal laryn-geal nerve and superior laryngeal artery

4. inferior constrictor and esophagus—conveys recurrentlaryngeal nerve and inferior laryngeal artery; the recur-rent laryngeal nerve changes names to the inferior laryn-geal nerve upon entering the larynx.


Abdominal wall muscles, 38Anterior forearm flexors,

175–176Arterial anastomosis at

elbow, 178Axillary artery branches,

167Back muscles, 124Biceps brachii

attachments, 170Brachial plexus, 189Carpal bones, 180Cubital fossa, 185Elbow movement, 195fEye innervation, 234Femoral triangle, 147, 148Hand musculature

innervation, 182Inhaled objects, 30Intercostal neurovascular

elements, 13

Interossei function, 182Intertubercular groove

muscle attachments,169

Lateral rotators of hipjoint, 130

Leg muscles, 140Long thoracic nerve, 165Lower limb, 157Lumbar plexus, 40Pectoral nerves, 190Pelvis nerves, 88Peritoneal cavity, 47Phrenic nerves, 247Popliteal fossa, 147Radial nerve, 177Scalp, 202Thigh muscles, 135Thoracoacromial trunk

branches, 167Thorax, 15

List of Mnemonics

260


261

Abdomen

area, 33–34

cavity, 33

embryologic arterial supply,

53

hernia

direct inguinal, 44, 47

indirect inguinal, 44, 47

intraperitoneal organs,

47

jejunum, 46flymphatics, 74–76

quadrants, 34

regions, 33

Abdominal wall

anterolateral, 37

arcuate line, 36

conjoint tendon, 36

endoabdominal fascia, 35

guarding reflex, 38

iliopubic tract, 36

inguinal canal, 34

deep inguinal ring, 34

inguinal ligament, 36

lacunar ligament, 36

pectineal ligament, 36

subinguinal space, 34

superficial inguinal ring,

35

investing fascia, 35

parietal peritoneum, 35

posterior, 37–38

rectus sheath, 35, 36

structures, 35–36

superficial fascia, 35

Aorta

abdominal, 22f, 39, 72

arch of, 17, 22fthoracic, 13

Arm, 167–172. See also Upper

limb

Artery(ies), 60falveolar

inferior, 216

posterior superior, 216

angular, 213

appendicular, 57

arcuate, 145

arterial arcades, 53

atrioventricular nodal branch,

25

auricular

deep, 216

posterior, 213

axillary, 166, 171

basilar, 209

brachial, 172

compression of, 172

deep, 172

brachiocephalic trunk, 17, 22f,245

bronchial, 14

right/left, 31

carotid, 242

common, 240

external, 240

internal, 208, 240, 243fleft common, 17, 22f

carpal arch

dorsal, 183

palmar, 183

celiac trunk, 50, 61, 62f, 65,

67, 69

cerebral

anterior, 209

arterial circle, 209, 210

middle, 209

posterior, 209

circumflex branch, left, 25

colic

left, 57

middle, 57

right, 57

communicating

anterior, 209

posterior, 209

coronary, 26

left, 25

right, 22f, 25

cremasteric, 39, 40, 42

Index

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Artery(ies) (continued)

costocervical trunk, 247

cystic, 60f, 65

digitals, dorsal, 146

dorsalis pedis, 145

dorsal scapular, 247

ductus deferens, 39, 42,

102

epigastric

inferior, 38

superficial, 39, 136

superior, 38

esophageal, 14

ethmoidal, 235

facial, 213

femoral, 136, 137

deep, 136

femoral circumflex

lateral, 137

medial, 137

fibular, 142

gastric

left, 50

right, 50

short, 50

gastroduodenal, 50, 67

gastro-omental

left, 50

right, 50

genicular, 141

descending, 137

gluteal

inferior, 89, 93, 130

superior, 89, 130

gonadal, 89

right/left, 72

hepatic, 50, 60f, 61, 65, 67

common, 60fleft branches, 60fright branches, 60fright/left, 61, 65

humeral, circumflex, 166,

172

ileocolic, 57

iliac

deep circumflex, 39

internal, 89

anterior, 89

posterior, 89

superficial circumflex, 39,

136

iliolumbar, 89

inferior epigastric, 45

infraorbital, 216

intercostal

anterior, 6, 10

posterior, 6, 10, 14

interosseous

anterior, 177

common, 177

posterior, 177

recurrent, 177

interventricular

anterior, 22f, 25

posterior, 25

lacrimal, 235

lower limb, 131flumbar, 39

mammary branch

lateral, 10

medial, 10

marginal, 57

left, 25

right, 25

maxillary, 216, 218

medullary, 120

meningeal, middle, 205,

216

mental, 213

mesenteric

inferior, 57, 62fsuperior, 53, 57, 60f, 62f,

67

metatarsals, dorsal, 146

musculophrenic, 38

nasal

dorsal, 234

lateral, 213

obturator, 89, 93, 136

occipital, 213, 242

ophthalmic, 234

palatine, descending,

216

palmar arch

deep, 182

superficial, 182

palmar digitals

common, 183

proper, 183

pancreatic

caudal, 67

dorsal, 67

great, 67

pancreaticoduodenal

anterior/posterior inferior,

67

anterior/posterior

superior, 67

262 INDEX


inferior, 53

superior, 52–53

pericardial, 14

phrenic

inferior, 74

superior, 14

plantar

arch, 146

deep, 146

digitals, 146

lateral, 146

medial, 146

metatarsals, 146

popliteal, 141

posterior ciliary, 235

princeps pollicis, 183

pudendal, 110

deep external, 137

internal, 89, 94, 130, 136

superficial external, 137

pulmonary, right/left, 31

pulmonary trunk, 22fradial, 177

radialis indicis, 183

radicular, anterior/posterior,

120

rectal

inferior, 57

middle, 57, 89, 94

superior, 57

renal, 74

right/left, 72

retina, central artery of, 234

sacral, lateral, 89

scapular, circumflex, 166,

172

scrotal

anterior, 40

posterior, 40

segmental, 72, 119

sigmoid, 57

sinuatrial nodal branch,

25

sphenopalatine, 216

spinal

anterior, 119

posterior, 119

splenic, 50, 60f, 67, 69

subclavian, 242

left, 17, 22fright/left, 165, 245

subcostal, 6, 14, 39

subscapular, 166, 172

supraorbital, 213, 234

suprarenal

inferior, 74

middle, 74

superior, 74

suprascapular, 166, 242

supratrochlear, 213, 234

tarsal, lateral, 145

temporal

deep, 216

superficial, 213

testicular, 39, 42

thoracic

internal, 6, 166

lateral, 166

superior, 166

thoracoacromial, 10, 166

thoracodorsal, 166, 172

thyrocervical trunk, 166

thyroid ima, 249

tibial

anterior, 142

posterior, 142

transverse cervical, 166

transverse facial, 213

tympanic, anterior, 216

ulnar, 177

anterior recurrent, 177

inferior collateral, 172

posterior recurrent, 177

superior collateral, 172

umbilical, 89

upper limb, 161futerine, 89

vaginal, 89, 93, 94, 96

vertebral, 116, 209

vesical

inferior, 89, 93, 94

superior, 89, 93

Back

suboccipital triangle, 124–125

Biliary tree, cholangiograph,

64fBone marrow harvesting, with

sternal puncture, 3

Bones

calcaneus, 142

capitate, 178

clavicle, 157

fracture, 162

coccyx, 126

Colles’ fracture, 173

coxal, 126–127

cuboid, 143

INDEX 263


Bones (continued)

cuneiform

intermediate, 143

lateral, 143

medial, 143

epiphysial rim, 114

ethmoid, 197

fibula, 138

fracture, 139

frontal, 197

hamate, 178

hard palate, 196

hip, 79–81, 126–127

gluteal lines, 79

hip pointer, 129

iliac crest, 79

ilium, 79

ischium, 79

humerus, 160f, 167–169

fracture, 169

ilium, 126–127

incus, 227

inferior nasal concha, 200

inferior articular processes,

115

ischium, 127

lacrimal, 200

lamina, 115

lower limb, 128fbones, 132

lunate, 178

malleus, 227

mandible, 198–199

fractures, 201

lingula, 199

maxilla, 198

metacarpals, 179

fracture, 180

metatarsals, 143

nasal, 200

navicular, 143

occipital, 197

palatine, 200

parietal, 197

pedicle, 115

pelvic, 126–127

pelvis, 78–81

acetabular notch, 79

acetabulum, 79

gluteal lines, posterior, 80

radiograph, 82fphalanges

distal, 143, 179

middle, 143

proximal, 143

pisiform, 178

pubic arch, 79

pubis, 81, 127

radius, 160f, 173

sacrum, 126

scaphoid, 178

fracture, 179fscapula, 157–158

shoulder, 157–159, 160fsphenoid, 197–198

spinous process, 115

stapes, 227

sternum, 2

superior articular processes,

115

talus, 142

temporal, 199–200

styloid process, 173

thoracic vertebrae, 2

tibia, 137–138

fracture, 138

transverse processes, 115

trapezium, 178

trapezoid, 178

triquetrum, 178

typical ribs of, 1

ulna, 160folecranon fracture, 173

uncinate process, 115

upper limb, 160fvertebral arch, 114, 116

vertebral canal, 116

vertebral foramen, 114, 116

vertebral notches, 115

vomer, 200

zygomatic, 200

zygomatic arch, 196

Brain, 202–210. See also Cranium;

Head

apertures

lateral, 208

median, 208

areas, 202

brainstem, 202

cerebellum, 202

cerebral aqueduct, 208

cerebrovascular accident,

209

choroid plexus, 208

concussion, 202

contusion, 202

diencephalon, 202

dural folds

cerebellar falx, 206

cerebellar tentorium, 206

264 INDEX


cerebral falx, 206

sellar diaphragm,

206

dural sinuses, 206–207

cavernous, 207, 208

confluence, 207

inferior sagittal, 207

occipital, 207

petrosal, 207

sigmoid, 207

straight, 207

superior sagittal, 206

transverse, 207

epidural space, 205

interventricular foramina,

208

meninges, 204, 205

arachnoid mater, 204, 205

granulations, 205, 208

trabeculae, 205

dura mater, 204, 205

pia mater, 204, 205

stroke, 209

subarachnoid cisterns,

208

subarachnoid space, 205,

208

subdural space, 205

ventricular system, 208

fourth ventricle, 208

lateral ventricles, 208

third ventricle, 208

Breast

area, 8

areola, 8

axillary process, 9

lactiferous duct, 9

lactiferous sinus, 9

mammary glands, 8

nipple, 8

quadrants, 10

retromammary space, 10

structure, 8–9, 9fsuspensory ligaments, 9

Clitoris, 100

Cranium, 196–202

bones, 196–201

neurocranium, 196

scalp, 201

viscerocranium, 196–201

Ear, 226–228fauditory tube, 227

bony labyrinth, 227

cochlea, 227

external, 227

infection, 228

inner, 227

membranous labyrinth,

227

middle, 227

organ of Corti, 227

saccule, 227

semicircular canals,

227

tympanic membrane,

227

utricle, 227

Esophagus, 13, 16, 239f, 255

constrictions, 14

pyrosis, 48

sphincters, 48

structure, 48

varices, 48

Eye. See Orbit

Face, 209–215, 212fFoot, 142–146

arches of, 147

avulsion, 143

fourth compartment,

151

inversion injury, 156fplantar aponeurosis,

152

plantar fasciitis, 152

Forearm, 173–178

elbow tendonitis, 176

tennis elbow, 176

Gallbladder, 60fbile duct, common, 63

body, 63

cholangiograph, 64fcystic duct, 63

fundus, 63

gall stones, 64fhepatopancreatic ampulla,

63

sphincter, 63

neck, 63

spiral valve, 63

Genitalia, female, 101fexternal, 99

external os, 95, 96

frenulum

of the clitoris, 99

of the labia minora,

99

INDEX 265


Genitalia, female (continued)

internal, 95–96

internal os, 96

labia

major, 99, 111

minora, 99, 111

mons pubis, 99, 111

ovaries, 98

prepuce of the clitoris,

99

pudendal cleft, 102

uterine tubes, 97

uterus, 96

vagina, 95

vaginal fornices, 95

vaginal vestibule, 95, 102

vulva, 102

Genitalia, male

bulbourethral glands, 104

ductus deferens, 102

ejaculatory ducts, 102, 103

external, 106

internal, 102–104

prostate, 102, 103–104, 105ffibrous capsule of, 103

prostatic sinuses, 103

prostatic utricle, 103

seminal colliculus, 103

seminal glands, 102–103

vasectomy, 104

Gluteal region, 126–132

acetabulum, 129

Hand, 178–183

Head. See also Brain; Cranium

connective tissue, 201

loose, 201

headache, 205

parasympathetic ganglia

ciliary, 236

otic, 236

pterygopalatine, 236

submandibular, 236

pericranium, 201

pterygopalatine fossa,

217–218

pterygomaxillary fissure,

218

sphenopalatine foramen,

218

scalp, 201

scalp trauma, 201

skin, 201

sphenomandibular ligament,

199

temporal region

intertemporal fossa, 215

structure, 215

temporal fossa, 215

Heart, 19–21

aortic sinuses, 21

aortic valve, 21, 23

aortic vestibule, 21

apex of, 22fatrioventricular valves,

right/left, 20

atrium

left, 21

right, 20

auricle, 21

left, 22f, 22fright, 22f

auscultation of, 23

bicuspid valve, 23

chordae tendineae, 20, 22fconus arteriosus, 21, 22fcoronary artery disease,

26

crista terminalis, 20

ductus arteriosus, 32

endocardium, 22

epicardium, 22

fibrous skeleton, 20

foramen ovale, 23

interatrial septum, 20

interventricular septum, 20

ligamentum arteriosum, 16,

22f, 32

muscular interventricular

septum, 22fmyocardium, 22

papillary muscles, 20,

22fpectinate muscles, 19

pulmonary sinuses, 21

pulmonary valve, 21, 23

septal defects, 23

septomarginal trabecula,

21

sinus venarum, 20

sulcus terminalis, 20

supraventricular crest,

21

surfaces, 19

trabeculae carneae, 19

tricuspid valve, 22f, 23

ventricle, 23

left, 21, 22fright, 21

walls of, 22

266 INDEX


Joint(s)

acromioclavicular, 192

dislocation, 195

ankle, 154

atlantoaxial, 117

atlanto-occipital, 117

carpometacarpal, 194

costochondral, 7

costotransverse, 8

costovertebral, 8

cricoarytenoid, 253

cricothyroid, 253

elbow, 193, 195ffemorotibial, 153

glenohumeral, 192–193

dislocation, 195

hip, 153

humeroradial, 193

humeroulnar, 193

intercarpal, 194

interchondral, 7

intercostal

1st, 7

2nd-7th, 7

interphalangeal, 155, 194

intertarsal, 155

intervertebral, 7, 117

knee, 153, 157finjuries, 157

lower limb, 153–155

manubriosternal, 7

metacarpophalangeal,

194

metatarsophalangeal, 155

pelvis, 82–83

pubic symphysis, 79, 83

radiocarpal, 194

radioulnar, 193

sacroiliac, 82

sacrotuberous, 82

scapulothoracic, 193

shoulder, 192–193

sternoclavicular, 7, 192

superior tibiofibular, 154

talocalcaneal, 155

talocrural, 154

tarsometatarsal, 155

temporomandibular, 220, 221

lateral ligament, 221

thoracic wall, 7–8

tibiofibular syndesmosis, 154

uncovertebral, 117

upper limb, 192–194

xiphisternal, 7

zygapophysial, 117

Kidney(s), 69–70

longitudinal section,

71fmajor calyces, 70

minor calyces, 70

pararenal fat, 70

perirenal fat, 70

renal

capsule, 70

cortex, 70

fascia, 70

hilum, 70

medulla, 70

papilla, 70

pelvis, 70

pyramid, 70

sinus, 70

stones, 72

transplantation, 72

urogram of, 71f

Large intestine, 54–55

anal

canal, 55

sphincters, 56

appendix, 54

barium radiograph,

anteroposterior, 56fcecum, 54

colon, 54

haustra, 55

McBurney’s point, 56

omental appendices, 55

pectinate line, 56

rectum, 55

teniae coli, 55, 57

Larynx, 250–255

arytenoid cartilages, 252

conus elasticus, 253

corniculate cartilages, 252

cricoid cartilage, 252, 254fcricothyroid ligament

lateral, 253

median, 252

cricotracheal ligament, 252

cuneiform cartilages, 252

epiglottic cartilage, 252

hypoepiglottic ligament,

252

infraglottic cavity, 251

laryngeal

cartilages, 250ffractures, 253

inlet, 250

prominence, 252

INDEX 267


Larynx (continued)

saccule, 251

ventricle, 251

vestibule, 250

quadrangular membrane, 253

skeleton, 252–253, 254fthyroepiglottic ligament, 252

thyrohyoid ligament

lateral, 253

median, 253

thyrohyoid membrane, 252,

253

thyroid cartilage, 252, 254fhorns

inferior, 252

superior, 252

laminae, 252

Valsalva maneuver, 251

vocal ligament, 253

Leg, 137–142. See also Lower

limb

compartment syndrome, 140

gastrocnemius strain, 140

plantarflexion, 141

shin splints, 140

Liver, 46fanatomic lobes, 59

caudate, 59

left, 59

right, 59

quadrate, 59

anterior view, 60fbare area of, 45, 59

cirrhosis, 60

extrahepatic duct system, 63

falciform ligament, 45, 46f,60f

functional divisions, 60

Glisson’s capsule, 58

hepatic ducts, 60fright/left, 59

common, 163

hepatic lobules, 58

peritoneum and, 45

porta hepatis, 59

portal hypertension, 61

portal triads, 58

round ligament, 60fsagittal fissure

left, 59

right, 59

structure, 58–59

Lower limb, 128f, 131fadductor canal, 147

areas, 146–147

compartment syndrome,

152

cribriform fascia, 151

crural fascia, 151

extensor retinacula, 151

falciform margin, 151

fascia lata, 150

fascia/connective tissue,

150–151

femoral

canal, 151

ring, 148

sheath, 151

triangle, 146, 147, 148,

148filiotibial tract, 150

joints, 153–155

plantar aponeurosis, 151

plantar fascia, 151

popliteal

fascia, 151

fossa, 147

saphenous opening, 151

superficial structures,

149–150

Lung(s), 30

cardiac notch, 30

fissures, horizontal/oblique,

30

hilum of, 30

left, 30

lingula, 30

right, 30

root of, 30

Lymphatics

abdominal, 74–76

lymph nodes, 11

wall, 74

axillary lymph nodes, 11

breast, 11

bronchopulmonary lymph

nodes, 32

cervical, deep, 213

cisterna chyli, 76

esophagus, 74

gall bladder, 76

head, 213

infraclavicular lymph nodes,

11

jugular angle, 17

jugular lymphatic trunk, 213

jugulodigastric node, 248

kidney, 76

large intestine, 75

larynx, 248

268 INDEX


lingual tonsils, 213

liver, 76

lower limb, 149

lungs, 32

lymphatic duct, right, 17, 76

lymphatic plexus, deep, 32

neck, 247–248

ovaries, 91

palatine tonsils, 213, 256

pancreas, 76

parasternal lymph nodes, 11

parathyroid, 248

pelvis, 90–91

penis, 91, 109

pharyngeal tonsils, 213, 256

pharynx, 248

prostate, 91

pulmonary lymph nodes, 32

seminal glands, 91

small intestine, 75

spleen, 75

stomach, 74

subareolar lymphatic plexus,

11

subclavian lymphatic trunk, 11

superficial lymphatic plexus,

32

supraclavicular lymph nodes,

11

suprarenal glands, 76

thoracic duct, 14, 17

thyroid, 248

tracheobronchial lymph nodes,

superior/inferior,

32

tubal tonsils, 213, 256

upper limb, 185

ureters, 76, 91

urethrae, 91

urinary bladder, 90

uterus, 91

vagina, 91

Waldeyer’s Ring, 213

Mediastinum, 18–26

Mouth. See Oral region

Muscle(s)

abdominal wall

cremaster, 37, 42

dartos, 37, 42

external oblique, 37

iliacus, 38

internal oblique, 37

psoas major, 38

psoas minor, 37

pyramidalis, 37

quadratus lumborum, 38

rectus abdominis, 37

transverse abdominal, 37

arm, 169–170

anconeus, 170

biceps brachii, 169

brachialis, 169

coracobrachialis, 169

tendonitis of biceps

brachii, 170

triceps brachii, 170

back, 122–124

deep layer, 123–124

extrinsic, 122

iliocostalis, 122

inferior oblique of the

head, 125

intermediate layer,

122–123

interspinales, 123

intertransversarii, 124

intrinsic, 122–124

levator costarum, 124

longissimus, 122

multifidus, 123

rectus capitis posterior

major, 125

rectus capitis posterior

minor, 125

rotators, 123

semispinalis, 123

spinalis, 123

splenius, 122

suboccipital triangle,

124–125

superficial layer, 122

superior oblique of the

head, 125

face, 210–212

buccinator, 211

corrugator supercilii,

211

depressor anguli oris, 212

depressor labii inferioris,

211

levator anguli oris, 211

levator labii superioris,

211

levator labii superioris

alaeque nasii, 211

mentalis, 212

nasalis, 211

occipitofrontalis, 210

orbicularis oculi, 211

INDEX 269


Muscle(s) (continued)

orbicularis oris, 211

platysma, 212

procerus, 211

risorius, 212

zygomaticus

major, 211

minor, 211

foot, 143–144

abductor digiti minimi,

144

abductor hallucis, 144

adductor hallucis, 144

dorsal interossei, 144

dorsum, 143

extensor digitorum brevis,

143, 145

extensor hallucis brevis,

144

flexor digiti minimi brevis,

144

flexor digitorum brevis,

144

flexor hallucis brevis, 144

lumbricals, 144

plantar interossei, 144

plantar surface, 144

quadratus plantae, 144

forearm, 174–175

abductor pollicis longus,

175

brachioradialis, 174

extensor carpi radialis

brevis, 175

extensor carpi radialis

longus, 174

extensor carpi ulnaris, 175

extensor digiti minimi,

175

extensor digitorum, 175

extensor indicis, 175

extensor pollicis brevis,

175

extensor pollicis longus,

175

flexor carpi radialis, 174

flexor carpi ulnaris, 174

flexor digitorum

profundus, 174

flexor digitorum

superficialis, 174

flexor pollicis longus, 174

palmaris longus, 174

pronator quadratus, 174

pronator teres, 174

supinator, 175

gluteal region, 129

gluteus

maximus, 129

medius, 129

minimus, 129

inferior gemellus, 129

obturator internus, 129

piriformis, 129

quadratus femoris, 129

superior gemellus, 129

tensor of fascia lata, 129

hand, 180–181

abductor digiti minimi,

181

abductor pollicis, 180

adductor pollicis, 180

dorsal interossei, 181

flexor digiti minimi, 181

flexor pollicis brevis, 180

hypothenar, 181

lumbricals, 181

opponens digiti minimi,

181

opponens pollicis, 180

palmar interossei, 181

thenar, 180–181

head

eyeball muscles, 233ffacial expression, 203

mastication, 203

larynx, 253, 254–255

cricothyroid, 254

cricopharyngeus, 48

lateral cricoarytenoid,

255

oblique arytenoid, 255

posterior cricoarytenoid,

255

thyroarytenoid, 255

transverse arytenoid, 255

vocalis, 254

leg, 139–140

anterior compartment,

139

extensor digitorum

longus, 139

extensor hallucis longus,

139

fibularis

brevis, 139

longus, 139

tertius, 139

270 INDEX


flexor digitorum longus,

140

gastrocnemius, 139, 140

lateral compartment, 139

plantaris, 139

popliteus, 139

posterior compartment,

139

soleus, 139

tibialis anterior, 139

triceps surae, 140

levator ani, 86

tendinous arch of, 86

neck, 244

anterior scalene, 244

digastric, 244

geniohyoid, 244

infrahyoids, 244

longus capitis, 244

longus coli, 244

middle scalene, 244

mylohyoid, 244

omohyoid, 244

posterior scalene, 244

prevertebral, 244

rectus capitis, 244

sternocleidomastoid, 244

sternohyoid, 244

sternothyroid, 244

stylohyoid, 244

suprahyoids, 244

thyrohyoid, 244

torticollis, 245

oral region

lateral pterygoid, 223

masseter, 223

mastication, 223

medial pterygoid, 223

temporalis, 223

orbit, 232

inferior oblique, 232

inferior rectus, 232

levator palpebrae

superioris, 232

medial rectus, 232

superior oblique, 232

superior rectus, 232

superior tarsal, 232

palate, 224

levator palati, 224

musculus uvulae, 224

palatoglossus, 224

palatopharyngeus, 224

tensor palati, 224

papillary, 20, 22f pectinate, 19

pelvis, 85

coccygeus, 85

iliococcygeus, 85

levator ani, 85

obturator internus, 85

piriformis, 85

pubococcygeus, 85

puborectalis, 85

perineum, 112

bulbospongiosus, 112

deep transverse perineal,

112

external anal sphincter,

112

external urethral sphincter,

106, 112

ischiocavernosus, 112

superficial transverse

perineal, 112

pharynx, 257–258, 259

constrictor, 259

inferior, 257

middle, 257

superior, 257

palatopharyngeus,

258

salpingopharyngeus, 256,

258

stylopharyngeus, 258

piriformis, 86

shoulder, 162–164

deltoid, 164, 165

infraspinatus, 164

latissimus dorsi, 163

levator scapulae, 163

pectoralis major, 162

pectoralis minor, 163

rhomboids, 163–164

serratus anterior, 163

paralysis, 164

subclavius, 163

subscapularis, 164

supraspinatus, 164

teres major, 164

teres minor, 164

trapezius, 163

teniae coli, 55, 57

thigh, 133–134

adductor

brevis, 134

longus, 134

magnus, 134, 135

INDEX 271


Muscle(s) (continued)

anterior compartment,

133

biceps femoris, 134

cramp, 135

gracilis, 134, 135

groin pull, 135

hamstrings, 135

iliacus, 133

medial compartment, 134

obturator externus, 134

pectineus, 133

pes anserinus, 135

posterior compartment,

134

psoas major, 133

psoas minor, 133

quadriceps femoris, 135

rectus femoris, 133

sartorius, 133

semimembranosus, 134

semitendinosus, 134

vastus

intermedius, 133

lateralis, 133

medialis, 133

thoracic wall, 3–4

diaphragm, 4

holes in, 5f intercostal

external, 3

innermost, 3

internal, 3

levator costarum, 4

proximal attachment, 4

serratus posterior

inferior, 4

superior, 4

subcostal, 3

transverse thoracic, 3

tongue, 223–224

extrinsic, 223–224

genioglossus, 223

hyoglossus, 223

intrinsic, 224

palatoglossus, 224

styloglossus, 224

Neck

alimentary structures,

255–259

axillary sheath, 238

carotid sheath, 238

cervical region

anterior, 240–241

lateral, 241–242

posterior, 241

superficial, 238

endocrine organs, 249–250

fascia, 237, 238, 239

deep cervical, 238

investing, 238

pretracheal, 238

prevertebral, 238

goiter, 249

hyoid, fracture, 237

parathyroid, 249

respiratory structures,

250–255

root, 245–246

skeleton, 237

spaces, 237, 238

retropharyngeal, 238

thyroid, 249

tonsillectomy, 248

veins, 240, 242, 245, 246, 247

Waldeyer’s Ring, 248

Nerve(s)

abdominal wall, 39–40

femoral, 40

genitofemoral, 40

iliohypogastric, 40

ilioinguinal, 40

lateral cutaneous nerve of

the thigh, 40

lumbar plexus, 39

lumbosacral trunk, 40

obturator, 40

subcostal, 39

thoracoabdominals, 39

arm, 170–171

axillary, 171


lateral cutaneous, 186

lateral pectoral, 171

long thoracic, 170

lower subscapular, 171

medial cutaneous, 186

medial pectoral, 171

median, 171

musculocutaneous, 171

radial, 171

to subclavius, 170

suprascapular, 170

thoracodorsal, 171

thoracodorsal injury, 171

ulnar, 171

upper subscapular, 171

brachial plexus, 188–189

diagram, 190f

272 INDEX


divisions, 189

inferior trunk, 189

lateral cord, 189

medial cord, 189

middle trunk, 189

posterior cord, 189

roots, 188

superior trunk, 189

breast, 10

anterior cutaneous

branch, 10

lateral cutaneous branch,

10

cranial, 203, 204fabducens, 203

facial, 203, 204

buccal branches,

214

cervical branches,

214

chorda tympani, 227

mandibular branches,

214

temporal branches, 214

zygomatic branches,

214

glossopharyngeal, 203

hypoglossal, 203

oculomotor, 203

olfactory, 203

optic, 203

spinal accessory, 203

trigeminal, 203, 204

trochlear, 203

vagus, 203

vestibulocochlear,

203

esophageal plexus, 48

esophagus, 48

face, 213–214

auriculotemporal, 214

buccal, 214

cervical spinal, 214

external nasal, 214

great auricular, 214

infraorbital, 214

infratrochlear, 214

lacrimal, 214

lesser auricular, 214

mandibular, 214

mental, 214

ophthalmic branches,

213–214

supraorbital, 213

supratrochlear, 213

zygomaticofacial, 214

zygomaticotemporal, 214

foot, 145

calcaneal, 145

deep fibular, 145

lateral plantar, 145

medial plantar, 145

medial sural cutaneous,

145

saphenous, 145

superficial fibular, 145

sural, 145

forearm, 176–177

anterior interosseous, 176

deep branch radial, 176

lateral cutaneous, 177, 186


median, 176

posterior cutaneous, 176,

186

posterior interosseous, 176

radial, 176

ulnar, 176

gallbladder, 65

genitalia, female, 96, 97, 98,

99, 100

genitalia, male, 41, 102, 103,

104, 106

anterior scrotal, 41

genital branch of

genitofemoral, 41,

42

perineal branches of

posterior femoral

cutaneous, 41

gluteal region, 130

clunial

inferior, 130

middle, 130

superior, 130

gluteal

inferior, 130

superior, 130

iliohypogastric, 130

to obturator internus, 130

posterior femoral

cutaneous, 130

pudendal, 130

to quadratus femoris, 130

sciatic, 130

hand, 182

median, 182

ulnar, 182

heart, 23–24

atrioventricular bundle, 24

INDEX 273


Nerve(s) (continued)

atrioventricular nodes, 24

deep cardiac plexus, 24

right/left bundle branches,

24

sinuatrial nodes, 24

superficial cardiac plexus,

23

visceral afferents of

cardiac plexus, 24

kidneys, 73

large intestine, 58

inferior rectal, 58

larynx, 255

leg, 141

common fibular, 141

deep fibular, 141

lateral sural cutaneous, 141


141

posterior femoral

cutaneous, 141

saphenous, 141


sural, 141

tibial, 141

liver, 61

lower limb, 149–150, 152

common fibular, 152

deep fibular, 150

femoral, 149, 152

genitofemoral, 149

iliohypogastric, 149

ilioinguinal, 149

inferior gluteal, 153

lateral plantar, 150

lateral sural cutaneous,

149

medial plantar, 150


149

obturator, 149

saphenous, 149

subcostal, 149


superior gluteal, 152

sural, 149

tibial, 150

lungs, 31

neck, 240, 245

ansa cervicalis, 245

brachial plexus, 241

cervical plexus, 241

hypoglossal distribution,

246f

left recurrent laryngeal,

245

nerve point, 241

phrenic, 245

right recurrent laryngeal,

245


suprascapular, 241

sympathetic ganglia, 247

sympathetic trunks, 245,

247

vagus, 245

orbit, 235

ciliary ganglion, 235

ethmoidal, 235

frontal, 235

lacrimal, 235

long ciliary, 235

nasociliary, 235

short ciliary, 235

pancreas, 68

pelvis, 86–87

inferior gluteal, 86

to levator ani, 87

to obturator internus, 87

to piriformis, 87

posterior femoral

cutaneous, 87

pudendal, 86

to quadratus femoris, 87

sacral plexus, 86, 88

sciatic, 86

superior gluteal, 86

perineum

pudendal, 110

pharynx, 258f, 259

posterior mediastinum, 13

pterygopalatine fossa, 218

deep petrosal, 218

greater petrosal, 218

maxillary, 218

pterygoid canal, 218

pterygopalatine ganglion,

218

sacral plexus, 86

shoulder, 164, 165

axillary, 165


long thoracic, 164, 165


supraclavicular, 165

small intestine, 53–54

spinal cord, 118–119

spleen, 69

stomach, 51

274 INDEX


superior mediastinum

left phrenic, 16

left recurrent laryngeal, 16

left vagus, 16

right phrenic, 16

right recurrent laryngeal,

16

right vagus, 16

suprarenal glands, 74

temporal region, 215, 217

auriculotemporal, 217

buccal, 217

inferior alveolar, 217

lingual, 217

mandibular, 215, 217

to mylohyoid, 217

otic ganglion, 217

thigh, 135–136

femoral, 135

genitofemoral, 136

lateral cutaneous, 149

lateral femoral cutaneous,

136

obturator, 135

posterior cutaneous, 150

posterior femoral

cutaneous, 136

sciatic, 136

thoracic wall

intercostal, 6

phrenic nerve injury, 5frami communicantes, 6

subcostal, 6

sympathetic trunk, 6

thoracic splanchnic, 6

upper limb, 186

brachial branches

variations, 191

brachial cord variations,

191

brachial division

variations, 191

brachial plexus variations,

191

inferior lateral cutaneous,

186

intercostobrachial, 186


median

nerve injury, 191

musculocutaneous

nerve injury, 191

pectoral, 190

radial

nerve injury, 191

supraclavicular, 186

terminal branches injury,

191

terminal branches of

median, 186


radial, 186


ulnar, 186

ulnar

nerve injury, 191

ureters, 73

urethrae, 95

urinary bladder, 93

Nose, 225–226

bloody, 226

choanae, 225

deviated septum, 226

external, 225

Kiesselbach’s area,

226

lateral walls, 225

meatuses, 225, 226

nares, 225

nasal

cavities, 225

conchae, 225

septum, 225, 226

paranasal sinuses, 226

sphenoethmoidal recess, 225,

226

Oral region, 219–225

cheeks, 219

dental arches, 219

gingivae, 219

lingual frenulum, 220

lips, 219

oral

cavity proper, 219

fissure, 219

vestibule, 219

palate, 220

palatine aponeurosis,

220

parotid

duct, 222

glands, 222

sheath, 222

pharynx

laryngopharynx, 221fnasopharynx, 221foropharynx, 221f

philtrum, 219

salivary glands, 222

INDEX 275



sialography, 223

sphenomandibular ligament,

221

stylomandibular ligament, 221

sublingual

ducts, 222

glands, 222

papilla, 222

submandibular

duct, 222

ganglion, 222

glands, 222

teeth, 219

tongue

foramen cecum, 220

midline groove, 220

terminal groove, 220

tongue tie, 222

uvula, 220

Orbit, 229–230

blowout fracture, 231

bulbar conjunctiva, 230

common tendinous ring,

234

conjunctivitis, 230, 232

exophthalmos, 231

eye, 229–230

choroid, 229

ciliary body, 229

ciliary process, 229

cornea, 229

fovea centralis, 230

iris, 230

macula lutea, 230

movements, 233f, 234

optic disk, 230

ora serrata, 230

sclera, 229

suspensory ligament, 234

eyelids, 228–230

lacrimal

papilla, 229

puncta, 229

medial canthus, 230

orbital septum, 229

palpebrae, 229

palpebral

conjunctiva, 230

ligament, 229

tarsal glands, 229

tarsal plates, 229

fascial sheath, 234

lacrimal

apparatus, 230

canaliculi, 230

caruncle, 230

ducts, 230

glands, 230

lake, 230

sac, 230

lateral check ligament,

234

retina, 231fOvaries, 98

broad ligament, 98

ligament of, 98

mesovarium ligament,

98

pampiniform plexus, 98

suspensory ligament, 98

vulva, 91

Pancreas, 46f, 66

accessory pancreatic duct, 66

body, 66

cancer, 67

head of, 60f, 66

hepatopancreatic ampulla, 66

main pancreatic duct, 66

major duodenal papilla, 66

minor duodenal papilla, 66

neck, 66

pancreatic duct sphincter,

66

tail, 66

uncinate process, 66

Pelvis

anorectal junction, 85

area, 77–78

connective tissue, 84–85

fascia, 84–85

endopelvic, 84

parietal layer, 84

prostatic sheath, 85

puboprostatic ligament, 84

pubovesical ligament, 84

rectovesical septum, 85

tendinous arch, 84

visceral layer, 84

female, 101fradiograph, 101f

greater, 78

greater sciatic foramen, 79, 81

ischiopubic ramus, 81

lesser, 78

lesser sciatic foramen, 79

male, midsagittal, 108fobturator

canal, 79

276 INDEX


fascia, 86

foramen, 79

pelvic

diaphragm, 86

floor trauma, 86

girdle, 78

inlet, 77

peritoneum of, 83–84

pregnancy and, 78

rectouterine pouch, 83, 84

retropubic space, 78

retrorectal space, 78

sacrospinous ligament, 81,

83

sex differences, 82

supravesical fossa, 83, 84

transverse acetabular

ligament, 79

transverse cervical ligament,

85

vesicouterine pouch, 83

Penile urethra, 106


external urethral sphincter,

106

membranous urethra,

106

urethral glands, 106

Penis, 107, 108

body, 108

corona, 109

corpora cavernosa, 107

corpus spongiosum,

107

deep fascia, 107

ejaculation, 109

erection, 109

fundiform ligament, 109

glans, 109

prepuce, 109

root, 108

suspensory ligament,

109

Pericardial cavity, 18

fibrous pericardium, 18

oblique sinus, 18

parietal layer of serous

pericardium, 18

pericarditis, 19

pericardium, 18

sac, 18

tamponade, 19

transverse sinus, 18

visceral layer of serous

pericardium, 18

Perineum

anal triangle, 110

area, 110

deep perineal pouch, 110

episiotomy, 111

fascia/connective tissue, 111

ischioanal fossae, 110

perineal body, 111

perineal membrane, 111

pudendal canal, 110

superficial fascia, membranous

layer, 111

superficial perineal pouch,

110, 111

urogenital triangle, 110

Peritoneal cavity, 42–44

ascending colon, 46fcolic flexure

left, 46fright, 46f

descending colon, 46fgreater omentum, 46fgreater sac, 43

hepatorenal recess, 43

inferior epigastric vessels, 45

inferior recess of omental

bursa, 46finfracolic compartment, 43

infracolic spaces, 46flesser omentum, 46flesser sac, 43

inferior recess of, 43

superior recess of, 43

ligament(s)

coronary, 45

falciform, 45, 46f, 60fgastrocolic, 45

gastrophrenic, 45

gastrosplenic, 45

hepatoduodenal, 45

hepatogastric, 45

medial umbilical, 47

median umbilical, 47

medial inguinal fossa,

47

mesentery, 46fomental bursa, 43

omental foramen, 43

paracolic gutters, 43,

46fparietal peritoneum, 46fperitoneal folds

lateral umbilical, 45

medial umbilical, 44

median umbilical, 44

INDEX 277


Peritoneal cavity (continued)

peritoneal fossae

lateral inguinal, 44

medial inguinal, 44

supravesical, 44

peritoneal relations, 47

phrenicocolic ligament,

46frectovesical pouch, 46frectum, 46f, 55

subdivisions of, 46fsubhepatic space, 46fsubphrenic spaces, 43

supracolic compartment, 43,

46ftenia coli, 46ftransverse colon, 46ftransverse mesocolon,

46ftriangular ligaments, 45

urachus, 47

urinary bladder, 46fvisceral peritoneum,

46fPeritoneum, 44–45

greater omenta, 45

lesser omenta, 45

liver and, 45

mesentery, 44

parietal peritoneum, 44

peritoneal folds, 44

portal triad, 45

round ligament of liver,

45

visceral peritoneum, 44

Pharynx, 256

auditory tube, 256

fascia, 258

pharyngobasilar, 256, 258

piriform fossa, 257

piriform recess, 256

salpingopharyngeal fold,

256

salpingopharyngeus, 256

swallowing, 257

tonsillar bed, 256

Pleural cavities, 26–27

cervical pleura, 26, 28

costal pleura, 26

costodiaphragmatic recesses,

right/left, 27

costomediastinal recess,

right/left, 27

diaphragmatic pleura, 26

endothoracic fascia, 26

mediastinal pleura, 26

pneumothorax, 28fpulmonary ligament, 26

visceral pleura, 27

Posterior mediastinum, 13–14

Prostate, 102–104, 105fenlargement, 105f, 106

Ribs, 1, 3

Scrotum, 37

Seminal glands, 102–103

Shoulder, 157–167

radiograph, 162frotator cuff, 165

Small intestine, 51–52

duodenojejunal junction, 52

duodenum, 46f, 51, 60fileocecal junction, 52

ileum, 52

jejunum, 52

Spermatic cord, 37, 41–42

autonomics of, 42

ductus deferens, 42

fascial coverings, 41

sensory innervation, 41

Spinal cord

cauda equina, 118

cervical enlargement, 118

dural sac, 118

epidural anesthesia, 121

gray matter, 119

lumbar

cistern, 118

enlargement, 118

puncture, 122

lumbosacral plexus, 118

medullary cone, 118

meninges, 120–121

arachnoid mater, 120, 121

arachnoid trabeculae,

121

denticulate ligaments, 121

dura mater, 120

dural root sheaths, 120

dural sac, 120, 121

epidural space, 120

filum terminale, 121

lumbar cistern, 121

pia mater, 120, 121

subarachnoid space,

121

subdural space, 121

278 INDEX


rami, anterior/posterior, 119

roots, anterior/posterior, 119

spinal block, 122

spinal ganglion, 119

white matter, 119

Spleen, 60f, 68

gastrosplenic ligament, 68

hilum, 68

splenomegaly, 68

splenorenal ligament, 68

Stomach, 46f, 49, 60fangular incisure, 49

body, 49

cardia, 49

cardial orifice, 49

fundus, 49

greater curvature, 49

lesser curvature, 49

pyloric antrum, 49

pyloric canal, 49

pyloric orifice, 49

pyloric sphincter, 49

pylorospasm, 50

pylorus, 49

rugae, 49

Superior mediastinum, 16–17

Suprarenal glands, 73

cortex, 73

medulla, 73

Testes, 105f, 106–107

pampiniform plexus,

107

tunica vaginalis, 106

Thigh, 132–137

bones, 132

coxa valga, 133

coxa vara, 133

femur, 132

fracture, 133

Thoracic cavity, 11, 12

anterior mediastinum, 12

inferior mediastinum, 12

inferior thoracic aperture, 12

intercostal space, 12

middle mediastinum, 12

posterior mediastinum, 12

superior mediastinum, 12

superior thoracic aperture, 12

thoracic outlet syndrome, 13

Thoracic wall, 1–8

intercostal nerve block, 4fsternal puncture, 3

thoracocentesis, 4f

Thorax

anteroposterior chest

radiograph, 27fThymus, 16

Trachea, 16

cartilages, 254fglottis, 251

rima glottidis, 251

rima vestibuli, 251

vestibular folds, 251

vocal folds, 251, 253

Tracheobronchial tree, 28–29

bronchopulmonary segments,

29

carina, 29

lobar bronchi, right, 29

left, 29

main bronchi, right/left, 29

segmental bronchi, 29

tracheal rings, 28

trachealis, 29

Upper limb, 185–186

anatomic snuff-box, 184

areas, 183–184

arteries, 161faxilla, 183–184

axilla wounds, 185

bones, 160fcarpal tunnel, 184

syndrome, 185

cubital fossa, 184

deltopectoral triangle, 184

dermatome maps, 187ffascia/connective tissue, 188

antebrachial, 188

axillary, 188

brachial, 188

clavipectoral, 188

costocoracoid membrane,

188

deltoid, 188

extensor retinaculum, 188

flexor retinaculum, 188

palmar, 188

pectoral, 188

superficial transverse carpal

ligament, 188

suspensory ligament of the

axilla, 188

lower triangular space, 184

quadrangular space, 184

upper triangular space,

184

INDEX 279


Ureters, 72

Urethrae, 94

catheterization, 94

female, 94

male, 94

Urinary bladder, 46f, 91–92

apex, 92

body, 91

detrusor muscle, 92

fundus, 92

internal urethral

orifice, 92

sphincter, 92

lymphatics, 90

median umbilical fold, 92

neck, 92

peritoneal relations, 92

urinary trigone, 92

Uterine tubes, 97

Uterus, 97

Vagina, 95, 96

Vein(s)

abdominal wall, 39

arm, 172

azygos, 14

basilic, 185

brachiocephalic

left, 17, 22f

right, 17, 22f

brain, 209

breast, 10

bronchial, right/left, 32


cardiac

anterior, 25

great, 25

middle, 25

small, 25

smallest, 25

cephalic, 185

clitoris, 100

coronary sinus, 25

cubital, median, 185, 186

ductus deferens, 102

ejaculatory ducts, 103

esophagus, 48

face, 213

female genitalia

external, 99

internal, 96

foot, 146

forearm, 177

median, 185

gallbladder, 65

gastric

left, 50

right, 50

gastro-omental

left, 50

right, 50

genitalia, female, 96, 97, 98,

99, 100

genitalia, male, 102, 103, 104,

106

gluteal region, 132

gonadal, 72

hand, 183

hemiazygos, 14

accessory, 14

hepatic, 61

inferior epigastric vessels, 45

jugular

anterior, 240

external, 242

internal, 240

jugular venous arch, 246

large intestine, 57

larynx, 251

leg, 142

lingual, deep, 222

lower limb, 149

lungs, 31–32

marginal, left, 25

medullary, 120

mesenteric

inferior, 60fsuperior, 60f, 62f

neck, 240, 242, 245, 246, 247

oblique vein of left atrium, 25

ophthalmic

inferior, 235

superior, 235

orbit, 235

ovaries, 98

pampiniform plexus, 39, 42

pancreas, 67

pelvis, 89

penile urethra, 106

penis, 107

perforating, 149

portal, 60f, 61, 62fleft branches, 60fright branches, 60f

prostate, 104

pterygoid venous plexus, 216

pudendal, 110

pulmonary, right/left, 31

280 INDEX


radicular, 120

renal, 72

retina, central, 235

saphenous

great, 149, 150

small, 149

scleral venous sinus, 235

seminal glands, 102

short, 50

small intestine, 53

spinal

anterior, 120

posterior, 120

spinal cord, 120

splenic, 60f, 62f, 69

stomach, 50

subclavian, 240, 242, 247

suprarenal

left, 74

right, 74

temporal region, 216

testes, 107

thigh, 137

thoracic wall, 6

upper limb, 185

urethrae, 95

urinary bladder, 93

uterine tubes, 97

uterus, 96

vagina, 96

vena cava

inferior, 22fsuperior, 17

venous angle, 246

venous arch, dorsal, 149

venous network, dorsal, 185

ventricular, left posterior, 25

vertebral venous plexus,

internal, 120

vestibule bulbs, 100

vorticose, 235

Vertebrae column, 113, 114–115

alar ligaments, 117

anulus fibrosis, 117

appendicular skeleton, 113

atlanto-occipital membranes,

anterior/posterior,

117

axial skeleton, 113

cervical, 115

coccygeal, 115

cruciform ligament, 117

curvatures, 113, 114fcervical, 113

excess, 114

lumbar, 113

sacral, 113

thoracic, 113

diagram, 116finterspinous ligament, 118

intertransverse ligaments, 118

intervertebral discs, 117

intervertebral foramina, 115

kyphosis, 114, 114fligamentum flavum, 117

ligamentum nuchae, 118

longitudinal bands, 117

longitudinal ligaments, anterior/

posterior, 117

lordosis, 114, 114flumbar, 115

nucleus pulposus, 117

ruptured disc, 118

sacral, 115

scoliosis, 114, 114fslipped disc, 118

spina bifida, 116

supraspinous ligament, 118

tectorial membrane, 117

thoracic, 115

transverse ligament of the

atlas, 117

vertebra prominens, 115

Vestibular glands, 100

Vestibule bulbs, 100

Vulva, ovaries, 91

INDEX 281


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