superior extremity

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SUPERIOR EXTREMITYPersonal Note (Excluding Figure)

Mohammad Shariful Alam (Shohan)

Session: 2003 04

Shahabuddin Medical College & Hospital


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SUGGESTIONS

1. Describe the structure of female mammary gland. Give its lymphatic drainage.

2. Draw and label the dermatome of upper limb. Give the importance of dermatome. What

is axial line?

3. Describe the clavipectoral fascia. Name the structures piercing it. What are the

peculiarities of clavicle?

4. Give origin, insertion and nerve supply of biceps brachii and pronator teres. What are

their actions on radioulnar joint?

5. Draw and label the brachial nerve plexus. A person suffered from wrist drop following

the fracture of the humerus, what will be the cause of wrist drop?

6. What is the boundary of the axilla? What are the contents of axilla? Mention the

different areas of lymphatic drainage to the different groups of axillary lymph nodes.

7. What are the ligaments of the shoulder joint? What is its common dislocation and why?

How abduction occurs up to 180?

8. Draw and label arterial anastomosis around the elbow joint. What is the clinical

importance of radial artery? How does it end in the hand?

9. Name the flexor muscles of the forearm with their nerve supply. Where is the common

origin of their superficial group? How the tendons of the deep flexor muscles are

inserted?

10.Write short note: I) Carpal tunnel ii) Synovial sheath of the palm iii) Rotator cuff iv) Axillary

sheath v) Bursa vi) Flexor retinaculam vii) Wrist drop viii) Anastomoses around scapula ix)

Bicipital aponeurosis x) Cubital fossa xi) Anatomical snuffbox xii) Claw hand.

11.Classify the joint. What are the characteristics of a typical synovial joint? What are the

factors responsible for the joint stability? Explain how the biceps brachii acts as both

prime mover and agonist on elbow joint.

12.What are the muscles supplied by the supraclavicular branches of brachial plexus? What

type of deformity is due to lower trunk injury?

13.Describe the shoulder joint mentioning its formation, movements and muscles producing

different movements. Give the common causes of shoulder dislocation. Why referred painfrom diaphragm felt in the shoulder tip?

14.Write the venous drainage of upper limb with its clinical importance . What is ape hand?

15.Give the root value of axillary nerve. What is axillary canal? Give the origin, insertion,

nerve supply and actions of deltoid and flexor digitorum profundus muscle.

16.Write briefly the lymphatic drainage of upper limb. What is the clinical importance of

lymphatic drainage of limbs?

17.Give the origin extension and branches of brachial artery. Draw and label the

anastomoses around the elbow joint.

18.What is pronation and supination of forearm? Give origin, insertion, nerve supply of

muscles producing these movements.

19.Describe the pectoral girdle with movement of scapula.20.Describe the course, branches & distribution of median nerve.

21.Describe the steps of dissection of cubital fossa. Draw and label the cutaneous nerve

supply of upper limb.

22.Write down the steps of dissection of the axilla. Name the muscles supplied by median

nerve with its injury.

23.Write briefly the anatomy of female breast . Describe the elbow joint.

24.Name the muscles of the palm. Mention their nerve supply. What are the age related

changes of mammary gland.


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SuperiorExtremity

Q. Describe the clavipectoral fascia. Name the structures piercing it.

Ans.Clavicupectorial fascia:

Synonym: Costocoracoid membrane.

Definition: Calvipectoral fascia is a strong fibrous sheet of contractile tissue situated deep to theclavicular portion of the pectoralis major muscle, filling in the space between the clavicle and

pectoralis minor muscle.

Extension:y Above: From the clavicley Below: To the axillary fascia

Attachment: Medially:Blends with the external intercostals membrane of the upper two spaces. Laterally: Attached to the coracoid process

At the lower border of subclavius the two layers fuse and may form a well-developed band, costocoracoid ligament, stretching from the knuckle of the coracoids to the firstcostochondral junction.

Enclosed muscles:i) It splits above to enclose subclavius and is attached to the edges of the subclavius groove

on the undersurface of clavicle.ii) Below, it splits to enclose the pectoralis minor muscle and then extends downwards as the

suspensory ligament of the axilla, which is attached to the axillary fascia over the floor ofthe axilla.

Structures piercing it:

The clavipectoral fascia is pierced by four structures two passing inwards, two passingoutwards.

Passing inwards are-(i) Lymphatics from the infraclavicular nodes to the apical nodes of axilla(ii) Cephalic vein

Passing outwards are-(i) Lateral pectoral nerve(ii) Thoraco acromial vessels.

Q. Describe the axilla with steps of dissection. / Give boundary and contents of axilla.

Ans.Axilla:The axilla, or armpit, is pyramid-shaped space between the upper part of the arm and

the side of the chest, bounded in front and behind by the axillary folds, communicating abovewith the posterior triangle of the neck and containing neurovascular structure and lymph nodes.

Steps of dissection:Skin incision:

y A curved incision along the anterior axillary fold beginning from the level of nippleextending laterally to arm for about 6.25 cm.


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y A longitudinal incision from the medial end of first incision extending downwards to theposterior axillary fold.

y A transverse incision from the lateral end of the first incision to the posterior border of thearm.

Shape and size: The shape and size of the axilla varies, depending on the position of the arm; italmost disappears when the arm is fully abducted.

Features:It resembles a four sided pyramid, and has(i) An apex(ii)A base(iii)4 walls anterior, posterior, medial and lateral.

Boundaries:1. Apex: It is the cervicoaxillary canal, directed upwards and medially towards the root of

the neck. It is truncated and bounded-a)Anteriorly by the posterior surface of clavicle

b)Posteriorly by the superior border of scapulac)Medially by the outer border of first rib

2. Base:Is directed downwards, and is formed by skin stretching between the anterior andposterior walls, subcutaneous tissue, and axillary (deep) fascia.

3. Anterior wall:It is formed by-(i) Pectoralis major in front, and(ii)The clavipectoral fascia enclosing the pectoralis minor and the subclavius.

4. Posterior wall:It is formed by-(i) Subscapularis above(ii)Latissimus dorsi and teres major below.

5. Medialwall:It is formed by-(i) Upper four or five ribs with their intercostal muscles and

(ii)Upper part of the serratus anterior muscle.

6. Lateralwall:It is formed by-(i) Upper part of the shaft of the humerus, and(ii)Coracobrachialis and short head of the biceps in the bicipital groove.

Contents of axilla:1. Axillary artery and its branches2. Axillary vein and its tributaries3. Infraclavicular part of the brachial plexus4. Five groups of axillary lymph nodes and the associated lymphatics5. The long thoracic and intercostobrachial nerves

6. Axillary fat and areolar tissue in which the other contents are embedded.

Q. Name the different lymph nodes in axilla. Name the area drain ed by differentlymph nodes. / Give a plan of lymphatic drainage of axilla. Give applied anatomy ofthe axillary group of lymph node.

Ans.Axillary lymph nodes:The fibro fatty connective tissue of the axilla contains many scattered lymph nodes.

Number:About 20 to 30 in number.


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Groups: The axillary lymph nodes are arranged in five principal groups anterior, posterior,lateral, central & apical.

i) Anterior or pectoral group:Number: 3 to 5 nodesSituation:Lying along the medial wall of the axilla with the lateral thoracic vein,

at the lower border of pectoralis minor.Afferent: From the upper half of the trunk anteriorly and from the major part of

the breast.Efferent: Into the central & apical nodes.

ii) Posterior or subscapular group:Number: 6 or 7 nodesSituation:Lie along the posterior axillary fold and subscapular blood vessels.

Afferent: From the upper half of the trunk posteriorly, & from the axillary tail ofthe breast.

Efferent: Into central & apical nodes.

iii)Lateral or humeral group:Number: 4 to 6 nodes

Situation:Lie along the lateral wall of the axilla, posteromedial to the axillaryvein.

Afferent: From the entire upper limb except that carried by lymphatic vesselsaccompanying the cephalic vein.

Efferent: Into central & apical lymph nodes.

iv) Central group:Number: 3 or 4 large nodesSituation: Deep to the pectoralis minor nears the base of axilla, in association

with second part of axillary artery.Afferent: From the preceding three groups.Efferent: Into the apical groups.

v) Apical group:Situation:At the apex of the axilla along the medial side of the axillary vein and

the first part of axillary artery.Afferent: From all other groups of axillary lymph a node as well as lymphatics

accompanying the proximal cephalic vein.Efferent:

y Efferent vessels unite to form the subclavian lymphatic trunk whichdrains as follows-

a)On the left side into the thoracic duct.b)On the right side into the right lymph trunk orc)Directly into the jugulosubclavian venous junction in the neck.

y A few efferents terminating into clavicular (infraclavicular and

supraclavicualr) nodes.Applied anatomy of axillary lymph nodes:

The axillary lymph nodes drain lymph from the upper limb, breast, and the anterior &posterior body walls above the level of umbilicus. So, infections or malignant growths in anypart of their territory of drainage give rise to involvement of the axillary lymph nodes.

An abscess in the axilla may arise from infection (lymphangitis) & suppuration of particulargroups of axillary lymph nodes.


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In metastatic cancer of apical group, the nodes often adhere to axillary vein, which maynecessitate excision of part of this vessel.

Enlargement of the apical nodes may obstruct the cephalic vein superior to the pectoralisminor.

Q. Give the steps of dissection of cubital fossa. Describe its boundaries & contents.Give the applied anatomy of cubital fossa.

Ans.Cubital fossa:

Definition:It is a triangular hollow situated on the anterior aspect of the elbow.

Steps of dissection:

1) A transverse incision in front of the elbow joint connecting the two humeral epicondyles.2) Another transverse incision at the junction of upper1/3rd and lower 2/3rd of the front of

the forearm.3) A longitudinal incision joining the mid points of the two transverse incisions.

Boundaries:A. Laterally - Medial border of the brachioradialis.B. Medially - Lateral border of pronator teres.C. Base - Is directed upwards, and is represented by an imaginary line connecting the

medial and lateral epicondyles of the humerus.D.Apex - Is directed downwards & is formed by the meeting point of the

brachioradialis & pronator teres.

Roof:Is formed by-(a)Skin(b)Superficial fascia containing the median cubital vein, the lateral cutaneous nerve

of the forearm and the medial cutaneous nerve of the forearm.(c) Deep (brachial and antibrachial) fascia(d)Bicipital aponeurosis

Floor:It is formed by supinator muscle laterally and the brachialis muscle medially.

Contents: The cubital fossa contains the following structures, enumerated from medial to lateralside-

1) Median nerve2) Terminal part of the brachial artery and the commencement of its terminal branches, the

radial and ulnar arteries.3) Biceps brachii tendon4) Radial nerve and its deep branches.

Applied anatomy:

The cubital fossa is important for the following reasons-

The median cubital vein is often the vein of choice for intravenous injection, bloodcollection, blood transfusion, and for cardiac catheterization.

Blood pressure is universally recorded by auscalting the brachial artery in front of theelbow.

In fracture of the elbow the anatomy of the cubital fossa is useful.

Q. Describe structure & development of female breast.

Ans.Structure of breast:

Structurally the breast is divided, from outward to inward, into-

1) Skin


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2) Parenchyma &3) Stroma.

1. Skin:It covers the gland & presents the following features:

a) Nipple: The nipple has a conical or cylindrical shape and may be pink, light brown ordark brown, and present just below the center of the breast. It is pierced by 15 to 20lactiferous ducts. Externally, it is covered by keratinized stratified squamous epithelium

which rests on a layer of connective tissue mostly rich in circular smooth muscle fibers.Contraction of the smooth muscle cells causes erection of the nipple.

b) Areola:A circular area formed by pigmented skin surrounding the base of the nipple iscalled areola. The area is rich in modified sebaceous glands, some sweat glands andaccessory mammary glands. The sebaceous glands are enlargedand from small elevations(tubercles ofMontgomery) during pregnancy & lactation. Oily secretions of these glandslubricate the nipple & areola and prevent them from cracking during lactation.

2. Parenchyma:Each mammary gland consists of15-20 lobes of the compound tubuloalveolartype, embedded in loose connective tissue, whose function is to secret milk to nourishnewborns. The myoepithelial cells and a dense network of capillaries surround the alveoli.Each lobule drains by its lactiferous duct and near the opening of the nipple, the ducts dilate

to form lactiferous sinuses.

3. Stroma:It forms the supporting framework of the gland. It is partly fibrous and partly fatty.j The fibrous stroma forms septa, known as the suspensory ligament (of Cooper) which

anchors the gland to the overlying skin.j The fatty stroma forms the main bulk of the gland. It is distributed all over the breast

except beneath the areola & nipple.

Development of breast:

Development of breast begins at 10-12 weeks from the milk ridge/mammary line which is anectodermal thickening that extends longitudinally from the axilla to groin through followingsequence of events-

Pectoral part of the ridge persists and rest regresses.

Ectoderm thickens as a mass of epidermal cells and projects into dermis and this form themammary glands on both sides.

About 15 to 20 outgrowths arise from this thickened epidermal mass and grow intodermis to get surrounded by fat, vascular and connective tissue.

The distal part of this outgrowths forms secretory elements and proximal part cannulatesto form lactiferous ducts.

All the ducts open into a pit which becomes elevated to form nipple.

The breast lobes develop at puberty in response to endocrine stimulation.

Q. Shortly describe the anatomy of female breast. Mention its lymphatic drainage. /Give lymphatic drainage and blood supply of breast.

Ans.Breast:

Definition:The breast is a modified sweat gland (apocrine type). It forms an important accessory organ

of the female reproductive system, and provides nutrition to the new born in the form of milk.

Situation:The breast lies in the superficial fascia of the pectoral region. A small part may extend

along the inferolateral edge of the pectoralis major towards the axillary fossa (armpit), forming anaxillary process or tail (ofSpence).


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Size & shape: Size & weight of the breast are variable at different ages and in differentindividuals.

Childhood rudimentary

Young adult female hemispherical

Later life pendular or variable in shape

Old age atrophied.

Extension:(i) Vertically: From second to the sixth rib.(ii)Transversely: From the lateral border of the sternum to the midaxillay line.

Deep relations: The deep surface of the breast is related to the following structures-

The breast lies on the deep fascia (pectoral fascia) covering the pectoralis major. Still deeper, two-thirds of it rests on pectoralis major, one-third on serratus anterior, while

its lower medial edge just overlaps the upper part of the rectus sheath. Between the breast and the pectoral fascia is a loose connective tissue plane or potential

space the retromammary space (bursa). This plane, containing a small amount of fat,allows the breast some degree of movement on the pectoral fascia.

Lymphatic drainage:

Breast is drained by two sets ofLymph vessels:-

(a)Lymphatics of the parenchyma of the breast.(b)Lymphatics of the skin over the breast.

Lymphatics of the parenchyma:

The lymph vessels originating from a plexiform network in the interlobular spaces and inthe walls of the lactiferous ducts converge towards the areola and form sub-areolar plexusofSappey. This receives lymph from the whole parenchyma and also from the skin ofareola and nipple.

The lymph from sub-areolar plexus is drained by two main lymph trunks one from itsinner and the other from its outer part; these two are uniting to form a single trunk whichends in the pectoral group of axillary lymph nodes. Before uniting these two trunksreceive a small lymph vessel draining the parenchyma directly.

From the upper & outer quadrant of the parenchyma one of the lymph vessels passupwards and pierces the deep fascia, pectoralis major, clavi-pectoral fascia and ends inthe apical group of axillary lymph nodes.

Some lymph vessels from the lower & inner quadrant of the parenchyma pass downwardsto communicate with the sub-peritoneal lymph plexus, passing through linea alba.

Lymphatics of the skin:

The lymph vessels of this group drain the whole skin over the breast except that of the areola andnipple.

1) The upper & outer quadrant is drained by two sets of lymph vessels; to the(a)pectoral group of axillary lymph nodes(b) infraclavicular lymph nodes.

2) The lower & outer quadrant is also drained by two sets; to the(a)pectoral lymph nodes


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(b) lymph nodes of abdominal parities.

3) The upper & inner quadrant is drained by three sets; to the(a) infraclavicular lymph nodes(b) internal mammary lymph nodes(c) lymphatics of the opposite side by crossing the midline.

4) The lower & inner quadrant is also drained by three sets; to the(a) lymph nodes of abdominal parities

(b) internal mammary lymph nodes(c) lymphatics of the opposite side by crossing the midline.

Blood supply:

Arterial supply:

1. Medial mammary branches of perforating branches and anterior intercostals branches ofinternal thoracic artery, originating from subclavian artery.

2. Lateral thoracic and thoracoacromial arteries, branches of axillary artery.3. Lateral mammary branches of lateral cutaneous branches of posterior intercostals arteries.

Venous drainage: The veins follow the arteries. They first converge towards the base of thenipple where they form an anastomotic venous circle, from which veins run in superficial and

deep set.

1. The superficial veins drain into the internal thoracic vein and into the superficial veins ofthe lower part of the neck.

2. The deep veins drain into the internal thoracic, axillary and posterior intercostals veins.

Nerve supply:

The nerves of the breast derive from anterior and lateral cutaneous branches of the4th-6th intercostal nerves. They convey sensory fibers to the skin of the breast and sympatheticfibers to the blood vessels in the breast and smooth muscle in the overlying skin and nipple.

Q. Describe the venous drainage of upper limb.

Ans.Venous drainage of upper limb: The venous drainage of upper limb are described below-

A) Dorsal venousarch:It lies on the dorsum of the hand.

Afferent(tributaries) :i) Three dorsal metacarpal veins,ii) A dorsal digital vein from the medial side of the little finger,iii)A dorsal digital vein from the radial side of the index finger,iv) Two dorsal digital veins from the thumb, andv) Most of the blood from the palm through veins passing around the margins of

the hand and also by perforating veins passing through interosseous spaces.

Efferent: Cephalic and basilic veins.

B) Cephalic vein:y It is a preaxial vein of the upper limb.y It begins from the radial side of the dorsal venous arch.y It crosses the roof of anatomical snuff box and winds around onto the anterior

aspect of the forearm. It then ascends into the arm and runs along the lateral border of biceps. On reaching the infraclavicular fossa it ends by piercing thedeep fascia in the deltopectoral triangle and enters the axillary vein.

y An accessory cephalic vein is sometimes present.


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C) Basilic vein:y It is postaxial vein of the upper limby It begins from the ulnar side of the dorsal venous arch.y It ascends along the dorsal postaxial border and reaches the anterior aspect just

below the elbow. Continues upwards along the medial margin of the biceps.Halfway up the arm, it pierces the deep fascia and at the lower border of the teresmajor joins the venae commitantes of the brachial artery to form axillary vein.

y Just below the medial epicondyle it usually receives the median antebrachial vein

and above the medial epicondyle receives the median cubital vein.

D) Median cubital vein:y It is a large communicating vein, which shunts blood from the cephalic vein to the

basilic vein.y It begins from the cephalic vein 2.5 cm below the bend of the elbow, runs

obliquely upwards and medially and ends in the basilic vein 2.5 cm above themedial epicondyle.

y It may receive tributaries from the front of the forearm and is connected to thedeep veins through a perforator vein.

E) Median vein ofthe forearm:

y It begins from palmer venous network and ends in anyone of the veins in front ofthe elbow.y Sometimes it divides into median cephalic & basilic veins which join the cephalic

and basilic veins respectively.

F) Axillary vein:y The vein is formed by the joining of the basilic vein and the brachial veins near

the distal margin of the teres major muscle.y The vein receives tributaries, which correspond to the branches of axillary artery,

and the cephalic vein.y It becomes subclavian vein at the distal edge of the first rib.

Q. What are the superficial veins of upper limb? Differentiate the large vein from

large artery. What are the nerves likely to be injured by fracture of ends & middle ofshaft of the humerus.

Ans.

Superficial veins of upper limb:i) Cephalic vein &ii) Basilic vein.

Differentiation of large vein from large artery:

See Omar Faruque Page 265

Nerves that likely to be injured by fracture of humerus:

i) At the upper end (at surgical neck): Axillary nerveii) Middle of the shaft (at the radial groove): Radial nerveiii)Lower end (behind the medial epicondyle): Ulnar nerve.

Q. Give the formation, course & distribution of cephalic vein.

Ans.Cephalic vein:It is the preaxial vein of the upper limb.

Formation:It begins from the lateral end of the dorsal venous arch.


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Course:

y It runs upwards through the roof of the anatomical snuff box.y Winds round the lateral border of the distal part of forearm.y Continues upwards in front of the elbow and along the lateral border of the biceps brachii.y Pierces the deep fascia at the lower border of pectoralis major.y Runs in the deltopectoral groove up to the infraclavicular fossa, where it pierces the

clavipectoral fascia.

y At the elbow, the greater part of its blood is drained into the basilic vein through themedian cubital vein, and partly also into the deep veins through the perforator vein.

Termination:It terminates into axillary vein.

Q. Describe the axillary artery.

Ans.Axillary artery:

Origin:It is the continuation of the third part of the subclavian artery.

Course:

It commences at the outer border of the first rib and enters the apex of the axilla bypassing over the digitations of serratus anterior, behind the midpoint of clavicle. Throughout the

course, the artery is closely related to the cords of the brachial plexus and their branches andenclosed with them a connective tissue sheath called axillary sheath. The medial root of mediannerve crosses in front of the artery to join the lateral root and form the nerve lateral to artery. Theaxillary vein lies anteromedial to all parts of the artery. At lower border of teres major it becomesthe brachial artery.

Parts: The axillary artery can be divided into three parts by the pectoralis minor muscle.

I. First part, superior (proximal) to the muscleII. Second part, posterior (or deep) to the muscleIII.Third part, inferior (distal) to the muscle.

I) First part:E

xtension:A

fter originating runs anteromedially along superior border of pectoralisminor, then passes between it and pectoralis major to thoracic wall.

Branches:y Superior thoracic artery- supplies the 1st and 2nd intercostals spaces and superior

part of serratus anterior.

II) Second part:Extension: This part lies posterior to pectoralis minor muscle.

Branches:y Thoraco-acromial artery curls around superomedial border of pectoralis minor;

pierces clavipectoral fascia; divides into four branches- pectoral, deltoid, acromialand clavicular.

y Lateral thoracic artery supplies lateral aspect of breast.

III) Third part:Extension: From the lateral border of pectoralis minor to the inferior border of the teres

major muscle.

Branches:y Subscapular artery (largest branch) has two terminal branches, the circumflex

scapular and thoracodorsal arteries.y Anterior circumflex humeral artery &y Posterior circumflex humeral artery.


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Q. Give the origin, extension, course, relation, termination a nd branches of brachialartery.

Ans.Brachial artery:It provides the main arterial supply to the arm.

Origin:It is the continuation of the axillary artery.

Extension:It extends from the lower border of the teres major muscle to a point in front of the

elbow, at the level of the neck of the radius, just medial to the tendon of the biceps.

Course and Relations:

y After its origin, it runs downwards and laterally, from the medial side of the arm to thefront of the elbow.

y It is superficial throughout its extent and accompanied by two venae comitantes.

y Anteriorly: The vessel is superficial and is overlapped from the lateral side by thecorachobrachialis and biceps.

In the upper part the medial cutaneous nerve of the forearm lies in front. In middle part the median nerve crosses it from the lateral to the medial side. In the lower part (in front of the elbow) it is covered by bicipital aponeurosis

and the median cubital vein.

y Posteriorly:It is related to(i) The triceps(ii)The radial nerve and the profunda brachii artery(iii)Insertion of the corachobrachialis, and(iv)The brachialis.

y Medially: In the upper part of the arm it is related to the ulnar nerve and the basilic vein. In the lower part of the arm the median nerve lies on its medial side.

y Laterally: In upper part it is related to the median nerve, corachobrachialis and biceps

muscle. In the lower part the tendon of the biceps at the elbow.

y Atthe elbow: The structures from lateral to medial side are (i) The radial nerve(ii)The biceps tendon(iii)The brachial artery, and(iv)The median nerve.

Termination:It terminates by dividing into radial and ulnar arteries.

Branches:

1. Unnamed muscular branches.2. Humeral nutrient artery.3. The profunda brachii artery (deep artery of the arm).

4. Superior ulnar collateral artery.5. Inferior ulnar collateral artery.6. Two terminal branches radialand ulnararteries.

Q. Describe radial artery.

Ans.Radial artery:

Origin: The radial artery is the smaller of the terminal branches of the brachial artery. It begins inthe cubital fossa at the level of the neck of radius.


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Course:

y Radial artery passes downward and medially, beneath the brachioradialis muscle andresting on deep muscles of the forearm.

y In the middle third of its course, the superficial branch of the radial nerve lies on itslateral side.

y In the distal part of the forearm, it lies on the anterior surface of the radius and is coveredonly by skin and fascia. Here, the artery has the tendon of brachioradialis on its lateralside and the tendon of flexor carpi radialis on the medial side.

y It leaves the forearm by winding around the lateral aspect of the radius to reach theposterior surface of the hand where it lies in the floor of the anatomical snuffbox.

y It leaves the dorsum of the hand by turning forward between the proximal ends if the firstand second metacarpal bones and the two head of first dorsal interosseous muscle.

y On entering the palm, it curves medially between the oblique and transverse heads of theadductor pollicis and continues as the deep palmer arch.

Branches:

A) In the fore rm:1)Radial recurrent artery2)Palmar carpal branch3)Unnamed muscular branches

4)A superficial palmar branchB) On the dors m of the hand:

1)The first dorsal metacarpal artery2)A dorsal carpal branch

C) In the palm:1)Arteria radialis indicis2)Arteria principes pollicis.

Q. Describe the anastomosis around the elbow joint. Give the site of feeling of arterialpulsation in the body.

Ans.Anastomosis around the elbow joint:

j This anastomosis links the brachial artery with the upper ends of the radial and ulnararteries.

j It supplies the ligaments and bones of the joint.

The anastomosis can be subdivided into the following parts

A. In frontofthe lateral epicondyle ofthe humerus: Anterior descending (radial collateral) branch of the profunda brachii

anastomoses with the radial recurrent branch of the radial artery.

B. Behind the lateral epicondyle ofthe humerus: The posterior descending branch of the profunda brachii artery (above)

anastomoses with the interosseous recurrent branch of the posterior interosseousartery (below).

C. In frontthe medial epicondyle ofthe humerus: The inferior ulnar collateral branch of the brachial artery, and occasionally a

branch from the superior ulnar collateral artery (above), anastomoses with theanterior ulnar recurrent branch of the ulnar artery (below).

D. Behind the medial epicondyle ofthe humerus:


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Superior ulnar collateral branch of the brachial artery (above) anastomoses withthe posterior ulnar recurrent branch of ulnar artery, and a branch from the inferiorulnar collateral artery (below).

E. Justabove the olecranon fossa: A branch from the posterior descending branch of the profunda brachii artery

(from the lateral side) anastomoses with a branch from the inferior ulnarcollateral artery (from the medial side).

Sites of feeling of arterial pulsation in the body:

o Radial arteryo Brachial arteryo Axillary arteryo Femoral arteryo Popliteal arteryo Anterior tibial arteryo Posterior tibial arteryo Arteria dorsalis pedis.

Q. Describe the lymphatic drainage of upper limb.

Ans.Lymphatic drainage of upper limb:

Lymph nodes: The chief lymph nodes of upper limb are the axillary lymph nodes, which arescattered in the fibrofatty tissue of the axilla. They are divided into five groups:

Anterior or pectoral groupPosterior or scapular groupLateral groupCentral groupApical group.

Other chief lymph nodes of the upper limb are-

Superficial:

Infraclavicular nodesDeltopectoral nodesSuperficial cubital or supratrochlear nodes

Deep:

A few other deep lymph nodes lie in the following regions-(i) Along the medial side of the brachial artery(ii)At the bifurcation of the brachial artery (deep cubital lymph node); and(iii)Occasionally along the arteries of the forearm.

Area of drainage of chief lymph nodes:

1) Anterior group: They receive lymph from the upper half of the trunk anteriorly and fromthe major part of the breast.

2) Posterior group: They receive lymph from the upper half of the trunk posteriorly, & fromthe axillary tail of the breast.

3) Lateral group: They receive lymph from the entire upper limb except that carried bylymphatic vessels accompanying the cephalic vein.

4) Centralgroup: They receive lymph from the preceding three groups.

5) Apicalgroup: They receive lymph from all other groups of axillary lymph a node as wellas lymphatics accompanying the proximal cephalic vein.


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6) Infraclavicular nodes: They drain the upper part of the breast, and the thumb with its web.

7) Deltopectoralnodes: It lies in the deltopectoral groove along the cephalic vein and drainssimilar structures such that of infraclavicular set.

8) Superficialcubitalnodes: They drain the ulnar side of the hand and forearm.

Lymhatics:

A. Superficial lymphatics: These are much more numerous than the deep lymphatics. They collect lymph from the skin of the fingers, palm, and dorsum of the hand

and also subcutaneous tissues. Most of them ultimately drain into the axillary nodes, exceot for

(i) A few vessels from the medial side of the forearm which drain into thesuperficial cubital nodes, and

(ii)A few vessels from the lateral side of the forearm which drain into thedeltopectoral or infraclavicular nodes.

Lyphatics from palm and fingers drain mainly to the dorsum of the hand and thenupwards along the superficial veins.

B. Deep lymphatics:

These are much less numerous than the superficial lymphatics. They drain structures lying deep to the deep fascia, e.g. from the joint capsules,

periosteum, tendons, nerves and muscles. They run along the main blood vessels of the limb, and end in the axillary nodes. Some of the lymph may pass through pass the deep lymph nodes present along

arteries.

Importance of median cubital vein:

The median cubital vein is often the vein of choice for

- intravenous injection,- blood collection,- blood transfusion, and

- for cardiac catheterization.

Q. Draw and label the brachial plexus. What is the effect of lower trunk compression?/ Describe the brachial plexus. Give the root value of axillary, ulnar &musculocutaneous nerves. What do you mean b y pre-fixed and post-fixed type ofbrachial plexus.

Ans.Brachial plexus:

Definition: It is a nerve plexus situated in the root of the upper limb.

Extension: It begins in the neck and extends in the axilla.

Development:As embryonic somites migrate to form extremities, they drag their nerve supply, so

that each dermatome and myotome retains the original segmental innervations. With somitemigration, some of the nerves come into close proximity and fuse in a particular fashion, forminga plexus.

Formation:

It is formed by the union of the anterior primary rami of the spinal nerves C5, 6, 7, 8& T1 sometimes with contributions from the anterior primary rami of spinal nerves C4 & T2 thatconstitutes the root of brachial plexus.


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Composition:It consists of

y Roots: Formed by the spinal nerves mentioned above, passes through the gap between theanterior and middle scalene muscles with the subclavian artery.

y Trunks: In the inferior part of the neck, the roots of the brachial plexus unite to formthree trunks-

(i) Superior trunk formed by the union of the C5 & C6 nerve roots.(ii)Middle trunk is a continuation of the C7 nerve roots.(iii)Inferior trunk formed by the union of the C8 & T1 nerve roots.

y Divisions:Each trunk of the brachial plexus divides into anterior and posterior divisionsas the plexus passes through the cervicoaxillary canal posterior to the clavicle.

(i) Anterior divisions of the trunks supply anterior (flexor) compartments of theupper limb.

(ii)Posterior divisions of the trunks supply posterior (extensor) compartments.

y Cords: Division joins to form the cords.(i) Lateralcord formed by the union of anterior divisions of superior & middle

trunks.(ii)Medialcord is the continuation of anterior division of inferior trunk.

(iii)Posterior cord formed by union of posterior divisions of all three trunks

Root values: The root values of

Axillary nerve C5, 6 Ulnar nerve C7, 8, T1. Masculo-cutaneous nerve C5, 6, 7.

Pre-fixed & post-fixed types of brachial plexus:

The roots of brachial plexus are formed by theanterior primary rami of spinal nerves C5, 6, 7, 8 & T1 with contributions from the anterior

primary rami of C4 & T2. The origin of the plexus may shift by one segment upward or

downward, resulting in a prefixed or postfixed plexus respectively.

Pre-fixed plexus: Here the contribution by C4 is large & that from T2 is often absent.

Post-fixed plexus: Here the contribution by T1 is large, T2 always present, C4 is absent, and C5is reduced in size.

Effect of lower trunk compression:

Compression of lower trunk of brachial plexus (less common) results in acondition called Klumpkes paralysis.

Cause of injury/compression:

It is caused by violent or prolonged upward displacement of the arm(as may occur in difficult breach delivery), dislocation of shoulder, apical tumors of the lung, acervical rib, or scalene syndrome. These events injure the inferior trunk of the brachial plexus andmay avulse the roots of spinal nerves from the spinal cord.

Nerve roots involved:Mainly T1 and partly C8.

Muscles paralyzed:

1. Intrinsic muscles of the hand (T1)2.Ulnar flexors of the wrist and fingers (C8).


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Deformity (position of the hand)-

Claw handdue to the unopposed action of the long flexors and extensors of the fingers.In a claw hand there is hyperextension at the metacarpo-phalangeal joints and flexion inthe interphalangeal joints.

Disability-

1. Claw hand.2. Cutaneous anesthesia and analgesia in a narrow zone along the ulnar border of the

forearm and hand.3. Horners syndrome ptosis, miosis, anhydrosis, enophthalmos, and loss of ciliospinal

reflex may be associated.

Q. What is Erbs point? Describe Erbs paralysis?

Ans. Erbs point: The region of the upper trunk of brachial plexus is called Erbs point. Sixnerves meet here. Injury to the upper trunk causes Erb-Duchenne paralysis (most common).

Erb-Duchenne palsy:

Cause of injury:Undue separation of the head from the shoulder, which is commonly encountered in

(i)B

irth injury(ii)Fall on the shoulder, and(iii)During anesthesia.

Nerve roots involved:Mainly C5 and partly C6.

Muscles paralyzed: Mainly biceps, deltoid, brachialis and brachioradialis. Partly supraspinatus,infraspinatus and supinator.

Deformity (position of the limb)-

y Arm: hangs by side; it is adducted and medially rotated.y Forearm: extended and pronated.

The deformity is known as waiters tip hand or policemans tip hand.

Disability-

1. Loss of abduction, and lateral rotation of the arm (shoulder).2. Flexion and supination of the forearm.3. Biceps and supinator jerks are lost.4. Sensations are lost over a small area over the lower part of the deltoid.

**Nice to know:

Branches of the plexus for the upper limb

A.Branches of the roots Long thoracic nerve (nerve to serratus anterior)

Dorsal scapular nerve (nerve to rhomboids)B. Branches of the trunks (These

arise only from the upper trunk) Suprascapular nerve

Nerve to subclavius

C.Branches of the cords Branches of lateral cord

Lateral pectoral nerve

Musculocutaneous nerve

Lateral root of median nerve

Branches of posteroir cord

Upper subscapular nerve

Nerve to latssimus dorsi

Lower subscapular nerve

Axillary (cicumflex) nerve


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Radial nerve

Brnches of medial cord

Medial pectoral nerve

Medial cutaneou nerve of arm

Medial cutaneous nerve of forearm

Ulnar nerve

Median root of median nerve.

Nerve Origin

Supraclavicular branches

Dorsal scapular C5 with a frequent contribution from C4

Long thoracic C5, C6, C7

Suprascapular C5, C6, and often C4

Nerve to subclavius (subclavian nerve) C5, C6 and often C4

Infraclavicular branches

Lateral pectoral C5, C6, C7

Musculo cutaneous C5, C6, C7

Median nerve Lateral root of median nerve is terminal

branch of lateral cord (C6, C7)

Medial root of median nerve is a

terminal branch of medial cord (C8, T1)

Medial pectoral

C8, T1Medial cutaneous nerve of arm

Median cutaneous nerve of forearm

Ulnar nerve C8. T1 and often C7

U pper subscapular C5

Lower subscapular C6

Thoracodorsal C6, C7, C8

Axillary C5, C6

Radial C5 - T1

Q. Draw and label the cutaneous supply of upper limb.

Ans.Cutaneous nerve supply of upper limb:See B. D. Chaurasias page no

Q. What is dermatome and axial lines? Describe dermatome of upper limb.

Ans.Dermatome:It is the area of the skin supplied by a single spinal nerve through its somatic

(general sensory and somatic motor) fibers.Axial line:

Axial line can be defined as a line along which certain dermatomes are buried (missing)and distant dermatomes adjoin each other, and across which the overlapping of the dermatomes isminimal.

There are two axial lines-i. Ventral extends down almost up to the wristii.Dorsal extends up to the elbow.

Dermatome of the upper limb:See Cunningham page no


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Q. Give the course and supply of median nerve. / Give the course & supply of mediannerve in forearm & hand. / Give the formation, distribution of median nerve. Mentionclinical condition arising by its lesion.

Ans.Median nerve:Median nerve is the principal nerve of the anterior compartment of theforearm therefore, called laborers nerve.

Origin:It arises from the medial and lateral cords of brachial plexus.

Root value: Lateral root of median nerve is terminal branch of lateral cord (C5, C6, and C7)Medial root of median nerve is a terminal branch of medial cord (C8, T1).

Course and Relation:

y Lateral and medial root merge to form median nerve lateral to axillary artery; descendsthrough arm adjacent to brachial artery.

In the upper part of the arm it lies lateral to brachial artery, In the middle of the arm it crosses the brachial artery from lateral to medial side.

y In the cubital fossa it lies medial to the brachial artery, behind the bicipital aponeurosis,and in front of the brachialis.

y The median nerve enters the forearm by passing between the two heads of the pronatorteres. Here it crosses the ulnar artery from which it is separated by the deep head of the

pronator teres.

y Along with the ulnar artery the nerve descends in fascial plane between flexor digitorumsuperficialis, and flexor digitorum profundus. A bout 5cm above the flexor retinaculum(wrist) it becomes superficial and lies between the tendons of flexor carpi radialis(laterally) and the flexor digitorum superficialis (medially). It is overlapped by the tendonof Palmaris longus.

y The median nerve enters the palm by passing deep to the flexor retinaculum, where it liesin front of ulnar bursa. Immediately below the retinaculum the nerve divides into lateraland medial divisions.

y The lateral division gives off a muscular branch to the thenar muscles, and three digitalbranches for the lateral one and half digits including the thumb.

y The medial division divides into two digital branches for the second and third digitalclefts, supplying the adjoining sides of the index, middle and ring fingers.

Branches and distribution:

In the arm:a. Vascular branches: To brachial artery.

In the forearm:a. Muscular branches: To superficial flexors of forearm, except flexor carpi ulnaris.

b.Anterior interosseous branch: To flexor pollicis longus, the lateral half of flexordigitorum prfundus and pronator quadrates. The nerve also supplies distalradioulnar and wrist joint.

c. Articular branch: To elbow & proximal radioulnar joint.

d.Vascular branches:Supply the radial and ulnar arteries.

e. A communicating branch: To ulnar nerve.

In the hand:a. Muscular branches: To abductor pollicis brevis, flexor pollicis brevis, opponens

pollicis, and the first and second lumbricals.

b.Palmar cutaneous branch:Supplies the skin over the thenar eminence and thecentral part of the palm.


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c. Palmar digital branches:Supplies the palmar skin of the lateral 3 digits, nail beds, skin on the dorsal aspect of the middle & distal phalanges of the samedigits.

Clinical conditions arising by its lesion:A. Motor loss:

1) Above the level of elbow:o The flexor pollicis longus is paralyzed, so the patient is unable to bend

terminal phalanx of the thumb, index and middle fingers when the proximalphalanx is hold firmly by the clinician.

o Due to paralysis of pronators the forearm is kept in a supine position.o Due to paralysis of the flexor carpi radialis the hand is adducted, and flexion

at the wrist is weak.o Flexion at interphalangeal joints of index and middle fingers will be

hampered.o Due to paralysis of the thenar muscles ape thumb deformity is present.

2) At the wrist:o Ape thumb deformity where the thenar muscles are wasted, and the thumb is

adducted and laterally rotated.

o Opposition of the thumb is totally lost.o Paralysis of first and second lumbricals makes the index and middle fingers

lag behind in slowly making a fist.

B. Sensory loss:Loss of sensation of skin over the lateral half of the palm, palmar aspect of

lateral 3 fingers & distal part of dorsal surfaces of lateral 3 fingers.

Q. Describe the course and supply of ulnar nerve.

Ans.Ulnar nerve:

Origin:It arises from the medial cord of brachial plexus.

Root value: C8. T1 and often C7 segments of spinal nerves.

Course:

y After originating, it runs on the medial side of the brachial artery up to the level ofinsertion of the corachobrachialis, where it pierces the medial intermuscular septum andenters the posterior compartment of the arm.

y At the elbow, the ulnar nerve lies behind the medial epicondyle of the humerus. It entersthe forearm by passing between two heads of flexor carpi ulnaris.

y In the forearm, the nerve runs between the flexor digitorum profundus and flexordigotorum superficialis (laterally).

y The ulnar nerve enters the palm by passing superficial to the flexor retinaculam where it

lies between the pisiform bone and the ulnar vessels. Here the nerve divides into itssuperficial and deep branches.

y The superficial terminal branch supplies the Palmaris brevis and divides into two digitalbranches for the medial 1 finger.

y The deep terminal branch passes backwards between the hypothenar muscles and fifthmetacarpal bone, lying on the hook of the hamate. Finally it turns laterally and ends bysupplying adductor pollicis muscle.


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Branches & distribution:1. Muscular branches: To-

j Flexor carpi ulnarisjMedial half of flexor digitorum profundusj Palmaris brevisj 3 hypthenarjMedial 3 lumbricalsjAll interossei

jAdductor pollicisj Often deep head of flexor pollicis brevis

2. Palmar cutaneous branches: Supplies the skin over hypothenar eminence.

3. Dorsal cutaneous branches: Supplies the proximal parts of the ulnar 2 fingers & theadjoining area of the dorsum of the hand.

4. Superficial branch in the hand.

5. Articular branches: Given off to elbow joint and wrist joint.

Q. Describe the axillary nerve. / Short note: Axillary nerve.

Ans.Axillary nerve:

Axillary (humeral circumflex) nerve is an important nerve because itsupplies the deltoid muscle which is the main abductor of the arm. Surgically it is important,

because it is commonly involved in dislocations of the shoulder and in fractures of surgical neckof the humerus.

Origin:It is one of the terminal branches of the posterior cord of the brachial plexus.

Root value:It receives contributions from the posterior divisions of roots C5C6.

Course and relations:y In the lower part of the axilla the nerve runs downwards behind the third part of axillary

artery. Here it lies in the subscapularis muscle. It is related medially to the median nerve,and laterally to the corachobrachialis.

y The nerve leaves the axilla by winding round the lower border of the subscapularis inclose relation to the lowest part of the capsule of shoulder joint, and enters thequadrangular space.

y The nerve than passes backwards through the quadrangular space. Here it is accompaniedby posterior circumflex humeral vessels and has following relations-

Superiorly:

(i) Subscapularis(ii)Lowest part of the capsule of the shoulder joint(iii)Surgical neck of humerus

Inferiorly: Teres major

Medially:Long head of the triceps

Laterally:Surgical neck of humerus.

It terminates by dividing into anterior and posterior branches in relation to the deltoidmuscle.

y The anterior branch is accompanied by the posterior circumflex humeral vessels. It windsround the surgical neck of the humerus, deep to the deltoid, reaching almost up to theanterior border of the muscle.

y The posterior branch pierces the deep fascia at the lower part of the posterior border ofthe deltoid and continues as the upper lateral cutaneous nerve of the arm.


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Branches and distribution:

a. Muscular (motor): To the deltoid and the teres minor. The nerve to teres minor bears apseudoganglion.

b. Cutaneous (sensory): The upper lateral cutaneous nerve of the arm supplies the skincovering the lower half of the deltoid and upper part of the long head of the triceps.

c. Articular: To the shoulder joint.

d. Vascular: Supplies the posterior circumflex humeral artery.

Applied anatomy:Damage to axillary nerve followed by dislocation of shoulder or by the fracture

of the surgical neck of the humerus results in

(i) Deltoid paralysis, with total inability to abduct the arm and severe impairment offlexion and extension at the glenohumeral joint.

(ii) The rounded contour of the shoulder is lost, and the greater tubercle of the humerusbecomes prominent.

(iii) There is sensory loss over the lower half of the deltoid.

Q. Describe the branches and distribution of the radial nerve. Give the appliedanatomy of radial nerve.

Ans.Radial nerve:

Branches and distribution:A. In the arm:

i. Muscular:Before entering the spiral groove supplies the long and medial heads of the

triceps.In the spiral groove supplies the lateral and medial heads of the triceps and

anconeus.Below the radial groove, on the front of the arm supplies the brachialis,

brachioradialis and extensor carpi radialis longus.

ii. Cutaneous branches:

Above the radial groove posterior cutaneous nerve of the arm which suppliesskin of the back of the arm.

In the radial groove it gives ofy Lower lateral cutaneous nerve of the army Posterior cutaneous nerve of the forearm

iii. Articular branches: To the elbow joint.

B. In the forearm:i. Superficial (sensory or cutaneous) branch of radial nerve distributed to skin on the

dorsum of the hand and to a number of joints in the hand.

ii. Deep branch of radial nerve/posterior interosseous nerve supplies motorinnervations to all the muscles in the posterior compartment of the forearm.

C. In the hand:On reaching the dorsum of the hand it divides into 4 or 5 dorsal digital branches

which supplies the skin of the digits as follows-

1st Radial side of the thumb & adjoining part of thenar eminence2nd Ulnar side of the thumb3rd Radial side of the index finger4th Contiguous sides of index & middle fingers5th When present it supplies the contiguous sides of the middle & ring fingers.


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Applied anatomy:

The characteristic clinical sign of radial nerve injury is wrist drop. Thecommon causes of radial nerve injury are-

i) Intramuscular injections in the arm (triceps)ii) Sleeping in an arm chair with the limb hanging by the side of the chair (saturday

night palsy), or even the pressure by crutch (crutch paralysis)iii) Fractures of the shaft of the humerus

iv) Supracondylar or epicondylar humeral fracturev) Fracture of the proximal third of the radiusvi) Deep (penetrating) wound of the forearm, etc.

Injury to the radial nerve superior to the origin of its branches to the triceps results in paralysis of the triceps, brachioradialis, supinator, and extensor muscles of the wrist andfingers. Loss of sensation in areas supplied by this nerve also occurs.

When the nerve is injured in the radial groove, triceps becomes weakened and the muscles ofthe posterior compartment of the forearm that are supplied by radial nerve are paralyzed.

Deep branch injury results in pronation of the hand, wrist drop, and inability to extend digitsand thumb.

Superficial branch injury results in loss of sensation to the dorsum of the hand and thumb

commonly, a coin shaped area of anesthesia occur distal to the bases of the 1st and 2ndmetacarpals.

Q. Name the thenar & hypothenar muscles with their nerve supply & actions. What iscarpal tunnel syndrome?Ans.

Thenar muscles with nerve supply & action:

Muscle Nerve supply Action

i) Opponens pollicis

Recurrent branch of mediannerve (C8, T1)

Pulls thumb medially and

forward across palm

(opposition)

ii)Abductor pollicis brevis Abducts thumb; helps oppose it

iii)Flexor pollicis brevis Flexes metacarpophangeal joint

of thumbSuperficial head

Deep head Deep branch of ulnar nerve(C8, T1)iv)Adductor pollicis Adducts thumb toward lateral

border of palm

Hypothenar muscles with nerve supply & action:


i) Palmaris brevis Superficial branch of ulnar

nerve (C8, T1)

Corrugates skin to improve grip

of palm

ii)A

bductor digiti minimi

Deep branch of ulnar nerve(C8, T1)

A

bducts the fifth digit; assistsin flexion of its proximalphalanx

iii)Flexor digiti minimi Flexion of the little finger at themetacarpophalngeal joint

iv)Opponens digiti minimi Draws 5th metacarpal forward

and rotates it, bringing 5th

finger into opposition with

thumb (flexion and opposition)


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Carpal tunnel syndrome:

Definition: The sensory and motor symptoms in the hand caused by compression of the mediannerve in the carpal tunnel.

Cause: The exact cause of the compression is difficult to determine. This syndrome may becaused by:

(a)Bony pathology like arthritic changes in the carpal bones, lunate dislocation, or an oldfracture of the wrist.

(b)Soft tissue pathology, like ulnar bursa inflammation, cystic swelling of the commonflexor synovial sheath, tenosynovitis, acromegaly, myxoedema, obesity, or toxaemia of

pregnancy.

Incidence:It usually occurs in females between the age of 40 and 70.

Characteristic features:(1)Paresthesia, hypoesthesia, or anesthesia may occur in the lateral three and half digits

(volar digital nerves).

(2)Because of the paralysis of the muscles of the thenar compartment (recurrent branch),flexion and abduction of the thumb is weak, and opposition is not possible. Individualshave difficulty buttoning a shirt or blouse as well as gripping things such as a comb.

(3)Paralysis of lumbricals I and II resulting inability to extend fully the first and second

fingers (negligible effect).(4)Sensation in the central palm remains unaffected as palmar cutaneous branch of median

nerve does not pass through the carpal tunnel.

Treatment: To relieve both the compression and the resulting symptoms, partial or completesurgical division of flexor retinaculum, a procedure called carpal tunnel release, may benecessary.

Q. Name the superficial group of muscles of forearm with nerve supply and action.

Ans.

A) Superficialmusclesofthe frontofthe forearm with nerve supplyand action :


i) Pronator teres Median nerve (C6, C7) Pronates and weakly flexes

forearm (at elbow)

ii) Flexor carpi radialis Median nerve (C6, C7) Flexes and abducts hand (at

wrist)

iii) Palmaris longus Median nerve (C7, C8) Flexes hand (at wrist) and

tenses palmar aponeurosis

iv) Flexor carpi ulnaris

Median nerve (C7, C8)

Flexes and adducts hand (at

wrist)Humeral head

Ulnar head Ulnar nerve (C7, C8)

v) Flexor digotorum

superficicalis(sublimus)

Median nerve (C7, C8, T1)Flexes proximal inter-

phalangeal joint, metacarpo-phalangeal joint, and wrist.

B) Superficialmusclesofthe backofthe forearmwith nerve supplyand action:


i) Anconeus Radial nerve (C7, C8, T1) Weak extensor of the elbow.


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ii) Brachioradialis Radial nerve (C5, C6, C7) Flexes forearm

It supinates the fully

pronated arm and pronates

the fully supinated forearm.

iii) Extensor carpi radialis

longus (ECRL)

Radial nerve (C6, C7) Extension of wrist

Abduction of wrist

Assists movements of the

digits by fixing the wrist.iv) Extensor carpi radialis

brevis (ECRB)Deep branch of radial nerve

(C7, C8)

v) Extensor digitorum

Posterior interosseous nerve(C7, C8)

Extends medial four fingers

primarily at metacarpo-

phalangeal joints,

secondarily at

interphalangeal joints.

When fist is clenched extends

wrist.

vi) Extensor digiti minimi

(EDM)

Extension the little finger at

the metacarpophalngeal and

interphalangeal joints.

Helps in extending the wristjoint.

vii)Extensor carpi ulnaris

(ECU)

Extends and adducts hand at

wrist joint

Q. Give the origin, insertion, nerve supply & action of the following muscles a) Biceps brachiib) Brachialisc) Palmaris brevis.

Ans.

Muscle Origin Insertion Nerve supply Action

Biceps

brachii Short head:From the

tip of the coracoidprocess of scapula.

Long head:From thesupraglenoidtubercle of thescapula & fromglenoidal labrum.

Into posterior

rough part of

radial tuberosity

of the radius

and bicipital

aponeurosis into

deep fascia of

forearm.

Musculo-

cutaneous nerve

(C5, C6)

i) It is a strong

supinator, when the

forearm is flexed.

ii)Flexor of the elbow.

iii)The short head is a

flexor of the arm.

iv)The long head

prevents upwards

displacement of the

head of the humerus.

Brachialis Front of lower half ofhumerus, including

the antermedial &

anterolateral surfaces

and the anteriorborder.

Medial & lateralintermuscular septa.

Into the-

oUlnar

tuberosity &

oRough anterior

surface of thecoronoid

process of ulna.

jMotor:

Musculo-

cutaneous

nerve.

jProprioceptive: Radial

nerve.

Flexes forearm at elbow

joint.

Palmaris

brevis

From-

Flexor retinaculum.

Medial border of

palmar aponeurosis.

Into the skin

over hypothenar

region.

Superficial

branch of ulnar

nerve (C8, T1)

It helps in gripping by

making hypothenar

eminence more

prominent and by

wrinkling the skin overit.


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Q. Give the origin, insertion, nerve supply & action of the following muscles a) Pronator teresb) Flexor digitorum profundusc) Supinatord) Deltoid muscle.

Ans.

Muscle Origin

Insertion Nerve supply

Action

Pronator

teres

Humeral head:Fromthe medialepicondyle of thehumerus.

Ulnar head:Fromthe medial margin ofthe coronoid processof the ulna.

Into the middle

one third of the

lateral surface of

the shaft of theradius.

Median nerve

(C6, C7)

v)Main pronator of the

forearm.

vi)It also flexes the

elbow.

Flexordigitorumprofundus

Upper 3/4th of the

anterior & medial

surface of the ulna.

Upper 3/4th of theposterior border of

the ulna by an

aponeurosis.

Medial surface of the

olecranon & coronoid

process of ulna.

Adjoining part of the

anterior surface of the

interosseous

membrane.

Into the palmar

surface of the

base of the distal

phalanges of themedial fourfingers.

jMedial half:

By ulnar

nerve.

jLateral half:By anterior

interosseous

nerve (C8,

T1)

i) Flexion of distal

phalanges of medial

four fingers.

ii)Secondarily it flexesthe other joints of

the digits & fingers

and the wrist.

iii)It is the chief

gripping muscle.

Supinator Lateral epicondyle ofhumerus.

Radial collateralligament of the elbow

joint.

Annular ligament.

Supinator crest of theulna, & the posterior

part of the triangular

area in front of it.

Into the upperone-third of the

lateral surface ofthe radius.

Posteriorinterosseous

nerve (C6, C7)

Supination of theforearm.

Deltoid Anterior border of thelateral one third of

the clavicle. Lateral border of the

acromion.

Lower lip of the crest

of the spine of the

scapula.

Into the deltoid

tuberosity of

humerus.

Axillary

nerve (C5, C6)

i) The anterior fibers

are flexors & medial

rotators of the arm.ii) The acromial fibers

are powerful

abductors of the

arm.

iii) The posterior fibers

are extensors &

lateral rotators of

the arm.


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Q. Enumerate the vertebra -scapular muscles. Give the origins, insertions, nervesupply & actions of three of them. What is winging of scapula? / Name the musclesconnect the scapula to the trunk. Mention their nerve supply. What are themovements performed by scapula.

Ans.Vertebra-scapular muscles:These are the muscles which connect upper limb with the

vertebral column. The muscles are

Trapezius Latissumus dorsi Levator scapulae Rhomoideus major Rhomboideus minor.

Origins,insertions, nerve supply & actionsofthree ofthem:

Muscle Origin Insertion Nerve supply Action

Trapezius Upper portion:From-

i) Medial third ofthe superiornuchal line of the

occipital boneii)The external

occipitalprotuberance

iii)Ligamentumnuchae

iv)Spine of C7.

Lower portion:From the spinesand supraspinousligaments of T1-T12.

jUpper fibers: Intothe posterior

border of lateral

third of clavicle.

jMiddle fibers:

Into the medialmargin of theacromion & upper

border of the

spine of the

scapula.

jLowest fibers: On

the deltoidtubercle at the

medial end of the

spine, with a

bursa intervening.

jMotor:Spinalpart of the

accessory

nerve.

jProprioceptive

:

From C3-C4.

i) Upper fibers:Elevate the scapula,

as in shrugging.

ii)Middle fibers: Pull

the scapula

medially.

iii)Lower fibers: Pull

the medial border of

the scapuladownward so that

the glenoid cavity

faces upward and

forward.

iv)Upper & lower

fibers are important

in abduction of the

arm beyond 90.

Latissimus

dorsi

From-

Posterior 1/3rd of

the outer lip of iliac

crest.

Posterior layer of

lumber fascia.

Spinous process of

T7-T12.

Lower three or four

ribs.

Inferior angle ofscapula.

Into the floor of

bicipital groove ofhumerus.

Thoracodorsal

nerve (C6, C7,C8)

i) It extends, adducts,

and mediallyrotates the arm (e.g.

swimming,

climbing)

ii)Helps in violentexpiratory effort

(e.g. coughing,

sneezing).

iii)Holds inferior angle

of scapula in place.

Levator

scapulae

From-

Transverse process

of C1, 2.

Posterior tubercles

of transverse

processes of C3, 4.

Into the superior

angle & upper part

of medial border

(up to triangular

area) of the scapula.

Third and fourth

cervical nerves

and dorsal

scapular nerve

(C5)

i) Retracts and

elevates scapula.

ii)Steadies the scapula

during movements

of the arm.

Rhomboids(Minor, Major)

Dorsal scapular

nerve (C5)


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Movementsofthe scapula:

Movement of Scapula Muscle Producing Movement Range ofMovement (angularrotation; linear displacement)

Elevation Trapezius,superiorpart

Levator scapulae

Rhomboids

10-12 cm

Depression Gravity

Pectoralis major, inferior -sternocostal head

Latissimus dorsi

Trapezius, inferior part

Pectoralis minor

Protraction Serratusanterior

Pectoralis major

Pectoralis minor40-45; 15cm

RetractionTrapezius, middle part

Rhomboids

Latissimus dorsi

Upward rotation Trapezius,superiorpartTrapezius, inferior part

Serratusanterior, inferiorpart

60; inferior angle: 10-12 cm;

superior angle: 5-6 cm

Downward rotation Gravity

Levator scapulae

Rhomboids

Latissimus dorsi

Pectoralis minorPecoralis major, inferior -

sternocostal head

Winged scapula:

The position of the scapula on the posterior wall of the thorax is maintained bythe tone and balance of the muscles attached to it. If one of these muscles is paralyzed, the

balance is upset.When the serratus anterior is paralyzed owing to injury to the long thoracicnerve (ofBell, C5-C7), on raising the arm the medial border of the scapula moves laterally and

posteriorly away from the thoracic wall, giving scapula the appearance of a wing, a conditionknown as winged scapula. This results in the inability to rotate the scapula during the movementof abduction of the arm above a right angle.

Causes oflong thoracic nerve injury:

Blows to or pressure on the posterior triangle of the neck or during surgical procedure ofradical mastectomy.

Weapons, including bullets directed towards the thorax.Any other cause resulting in severe injury to the root of brachial plexus.

Q. What do you mean by supination & pronation of fo rearm? Name the joints wherethese movements occur. What types of joints are these? Name the muscles involved insupination & pronation.

Ans.

Supination:It is the rotational movement of the forearm and hand that swings the radius laterallyaround its longitudinal axis so that the dorsum of the hand faces posteriorly and the palm facesanteriorly. When the elbow joint is flexed, supination moves the hand so that the palm facessuperiorly.


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Pronation:It is the rotational movement of the forearm and hand that swings the radius mediallyaround its longitudinal axis so that the palm of the hand faces posteriorly and its dorsum facesanteriorly. When the elbow joint is flexed, pronation moves the hand so that the palm facesinferiorly.

Joints where these movements occur: At thei. Superior radioulnar joint &ii. Inferior radioulnar joint.

Types of the joint:They are pivot (a joint that moves by rotating) type of synovial joint.

[Pivot joint: A pivot joint is a synovial joint in which the ends of two bones meetone end being a central bony

cylinder, the other end being a ring (or ring-like structure) made of bone and ligament. In some joints, the cylinder

rotates inside the ring. In other joints, the ring rotates around the cylinder.]

Muscles involved in these movements:

Supination Pronationj Supinator(when resistance is absent)j Biceps brachii (when power is required because of resistance)

jWith little assistance from- Extensor pollicis longus (EPL)

Extensor carpi radialis longus (ECRL)

jPronator quadrates (primarily)jPronator teres (secondarily)

jWith little assistance from- Flexor carpi radialis (FCR)

Palmaris longus

Brachioradialis.

Q. Give the origin, insertion & nerve supply of the muscles causing pronation &supination of forearm. / Describe the supinators of forearm. Name the pronators offorearm. / Enumerate the movements of superior & inferior radio -ulnar joints.Mention the muscles involved in these movement s. Give their nerve supply.

Ans.

Movements involving superior & inferior radioulnar joints:

1) Supination &2) Pronation.

Muscles producing pronation; their origin, insertion & nerve supply:

Muscle Origin Insertion Nerve supply

Pronator quadratus From the oblique

ridge on the lower

1/4th of the anterior

surface of the shaft of

ulna & the area medial

to it.

oSuperficial fibers:

Into the lower 1/4th

of the anterior

surface & anterior

border of radius.

oDeep fibers: Into the

triangular area

above the ulnarnotch.

Anterior interosseous

nerve, from median

nerve (C6, C7)

Pronator teres Humeral head:From the medialepicondyle of thehumerus.

Ulnar head:Fromthe medial marginof the coronoidprocess of theulna.

Into the middle one

third of the lateral

surface of the shaft of

the radius.

Median nerve (C6, C7)


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Muscles producing supination; their origin, insertion & nerve supply:

Muscle Origin Insertion Nerve supply

Supinator Lateral epicondyle

of humerus.

Radial collateral

ligament of the

elbow joint.

Annular ligament. Supinator crest of

the ulna, & the

posterior part of

the triangular area

in front of it.

Into the upper one-third of the lateral

surface of the radius.

Posterior interosseousnerve (C6, C7)

Biceps brachii Short head:Fromthe tip of thecoracoid process ofscapula.

Long head:Fromthe supraglenoid

tubercle of thescapula & fromglenoidal labrum.

Into posterior rough

part of radial

tuberosity of the

radius and bicipital

aponeurosis into deep

fascia of forearm.

Musculo-cutaneous

nerve (C5, C6)

Q. Describe the shoulder joint. What is rotator cuff?

Ans.The shoulder joint:

Articulation: This occurs between the-i) Rounded head of the humerus &ii)Shallow pear shaped glenoid cavity of scapula.

The articular surfaces are covered by hyaline cartilage, and the glenoid cavity is deepened by the

presence of a fibrocartilaginous rim called glenoid labrum. Stucturally it is a weak joint, becausethe glenoid cavity is too small & shallow to hold the head of the humerus in place.

Type:Ball & socket type of synovial joint.

Capsule: The loose fibrous layer of the joint capsule surrounds the glenohumeral joint and isattached-

Medially to the margin of glenoid cavity Laterally to the anatomical neck of the humerus. Superiorly this part of joint capsule encroaches on the root of the coracoid process. The inferior part of the joint capsule, the only part not reinforced by rotator cuff muscles,

is its weakest area.

Factorsmaintainingstability:

y The coracoacromial arch.y The musculotendinous rotator cuff of the shoulder.y The glenoid labrum.y Muscles attaching the humerus to the pectoral girdle, the long head of biceps, the long

head of the triceps.y Atmospheric pressure.

Ligaments:

y Glenohumeral ligament.


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y Transverse humeral ligament.y Coracohumeral ligament.y Accessory ligament: Coracoacromial ligament.

Blood supply:

y Anterior circumflex humeral arteryy Posterior circumflex humeral arteryy Suprascapular artery

y Subscapular artery.

Nerve supply:Byy Axillary nervey Musculocutaneous nerve, andy Suprascapular nerve.

Musclesbringingaboutmovementsatthe shoulder joint:

Movements Main muscles Accessory muscles

1. Flexion Clavicular head of pectoralis major

Anterior fibers of deltoid

Coracobrachialis

Short head of buceps

Sternocostal head of pectoralis major

2. Extension Posterior fibers of deltoidLatissimus dorsi

Teres majorLong head of triceps

3.Adduction Pectoralis majorLatissimus dorsi

Teres majorCoracobrachialis

Short head of biceps

Long head of triceps

4.Abduction Deltoid

Supraspinatus

Serratus anterior

Upper and lower fibers of trapezius

5.Medial rotation Pectoralis major

Anterior fibers of deltoid

Latissimus dorsi

Teres major

Subscapularis

6. Lateral rotation Posterior fibers of deltoid

Infraspinatus

Teres minor

superior extremity

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