kovacs anatomy

8/8/2019 Kovacs Anatomy

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UPPER LIMB

PECTORAL REGION(including Infraclavicular region)Superior: clavicle,

Lateral: deltoidopectoral sulcus,

Inferior: inferior margin of the pectoralis major,

SKIN INNERVATION:

Medial and intermediate supraclavicular nerves (from the cervical plexus),

Anterior cutaneous branches of the intercostal nerves.

Just underneath the skin is the superficial pectoral fascia (covering the pectoralis major) whichcontinues in the axillary region to become the superficial axillary fascia (base-floor of the axillary fossa

together with the skin). By removing the fascia, we will find thepectoralis majormuscle.Thepectoralis minormuscle lies deep to thepectoralis major. It must be cut to dissect the axillary

artery, vein, and the cords of the brachial plexus. By lying over the middle of the axillary artery, it divides

the artery into three parts (proximal to the muscle, covered by the muscle, and distal to the muscle).

Axillary artery: 1st part: Superior thoracic artery + thoracoacromial artery

2nd part: Lateral thoracic artery + subscapular artery

3rd part: Anterior and posterior circumflex humeral arteries.

The largest branch is the subscapular artery, giving the branches circumflex scapular and thora-

codorsal arteries.

The axillary vein is medial to the axillary artery which is surrounded by the cords of the brachialplexus.

Brachial plexus: It comes from the ventral rami of the spinal nerves C5-T1. The spinal nerves come out

from the vertebral canal through the intervertebral foramen. When they come out, they divide into

anterior (ventral) and posterior (dorsal) rami.

Above the clavicle, the brachial plexus forms three trunks:

Superior trunk: C5-C6

Middle trunk: C7Inferior trunk: C8-T1

The lateral cord is formed by the superior and middle trunks, the medial cord by the inferior trunk, and

the posterior cord from all three.

The musculocutaneous nerve pierces through the coracobrachialis muscle, and it goes below thebrachialis muscle. At the distal end, it becomes the lateral antebrachial cutaneous nerve that comes out

from below the biceps at the lateral side of the tendon (running together with the cephalic vein).

TheMedian nerve arises from the medial and lateral cords (having the appearance of a V-shaped

nerve), and it runs through the medial bicipital groove on the arm together with the ulnar nerve, the medial

brachial cutaneous and medial antebrachial cutaneous nerves, and the brachial artery. Then, it goes to the

cubital fossa (at the middle), and it is the most medial structure of the cubital fossa. The middle structure

is the brachial artery, and the lateral structure is the tendon of the biceps muscle. The median nerve (after

the cubital fossa) goes to the forearm between the flexor digitorum superficialis (in its fascia) and the

flexor digitorum profundus in the midline of the forearm (that's why it's called the median nerve). Then, itgoes through the carpal canal. In the palmar region, it is covered by thepalmaris longus tendon. If thismuscle is missing, the nerve runs between theflexor carpi radialis tendon and theflexor digitorum


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tendons. In the palm, it divides into superficial and the deep branches. The deep branch innervates the

thenar muscles (except the adductor) and the 1st and 2nd lumbricals. The superficial branch innervates the

skin of the palm and the lateral 3 fingers by seven digital branches.

The Ulnar nerve arises from the medial cord of the brachial plexus and runs though the medial

bicipital groove on the arm, but leaves the groove and pierces through the medial intermuscular septum

and goes to thesulcus nervi ulnaris. Then, it reaches the forearm between the two heads of theflexorcarpi ulnaris muscle. In the inferior 1/3 of the forearm, we can find the ulnar nerve covered by theflexordigitorum profundus together with the ulnar artery. The ulnar artery, in the superior 1/3 of the forearm, is

between the deep and the superficial muscles, and afterward it joins the ulnar nerve.

The ulnar nerve goes into the palm in front of the flexor retinaculum (it doesn't pass through the

carpal canal) together with the ulnar artery, where it gives superficial and deep branches. The deepbranch innervates the interossei muscles, the 3 rd and 4th lumbricals, the adductor pollicis, and the

hypothenar muscles. The superficial branch innervates the ulnar 1 fingers, the ulnar 1/2 of the palm, and

thepalmaris brevis.

The medial brachialand antebrachial cutaneous nerves arise from the medial cord of the brachial

plexus and are found in the medial bicipital groove. The medial antebrachial cutaneous nerve pierces thebrachial fascia through the basilic hiatus and joins the basilic vein. The medial brachial cutaneous nerve

anastomoses with the 1st, 2nd (and sometimes 3rd) intercostal nerves. This anastomosis is called the

intercostobrachial nerve (innervates the skin of the axilla).

TheRadial nerve arises from the posterior cord of the brachial plexus. It is located in front of thetendon of latissimus dorsi muscle and the teres major, runs to the superior part of the sulcus bicipitalis

medialis, and leaves the sulcus (it is not a structure of the sulcus) where it goes to the extensor muscles of

the arm between the triceps (medial and lateral head) into the sulcus nervi radialis. Then, it comes

forward again in the cubital region (not into the cubital fossa) in the lateral side between the brachialis and

brachioradialis muscles. You must move apart those two muscles to find the nerve.

There it divides into two branches (superficial and deep). The superficial branch innervates the radial

2 fingers (by digital nerves) and skin at the dorsal side of the hand. The deep branch pierces through thesuperficial muscles (supinator) and innervates the extensor muscles.

TheAxillary nerve arises from the posterior cord of the brachial plexus and gives skin branches

(lateral cutaneous branches) that are not dissectable.


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AXILLARY REGIONThe region basically consists of the axillary fossa; however, it also includes the skin covering the

walls of the fossa. If described as a surface region of the anterior side of the body (as it is usually

presented), the axillary region is a triangular wedge (the most lateral portion of the Pectoral region):

Lateral: Deltopectoral sulcus

Medial: Thoracic wall, projected onto the skinInferior: Anterior axillary foldThe axillary fossa pyramid-shaped fossa. Its base is open, but it is defined by the anteriorand

posterior axillary folds (frequently forgotten!). This pyramid has four solid walls:

Anterior: Pectoralis major and minor muscles,Posterior: Subscapular, teres major, and latissimus dorsi,Medial: Thoracic wall and serratus anterior,

Lateral: Humerus, flexors of the arm, and coracobrachialis.

The clavipectoral fascia continues to the superior axillary fascia which keeps the skin fixed to the

axillary fossa. In the axillary fossa, there are lymph nodes.

In the axillary region, structures (nerves, veins, arteries) are the same as in the pectoral region.

Medial rotators of the humerus: latissimus dorsi, teres major, subscapularis (all attached to the crest of

the lesser tubercle).Lateral rotators of the humerus: teres minor, infraspinatus.

ORIGINSAND INSERTIONS:

Biceps: Supraglenoid tubercle Tuberosity of radiusCoracoid process

Coracobrachialis: Coracoid process middle of the shaft of the humerus

Brachialis: Lower half of humerus Condyloid process of ulna

ANTERIOR BRACHIAL REGIONSuperior: Inferior border of the pectoralis major muscle,

Inferior: Three fingers above the cubital sulcus,Medial: Medial margin of the arm,

Lateral: Lateral margin of the arm (lat and med defining the volar surface of the arm).

SKIN INNERVATION:

Medial brachial cutaneous Nerve (medial cord of brachial plexus)

Lateral brachial cutaneous nerve (end branch of the axillary nerve- usually not dissectible)

SUPERFICIAL STRUCTURES:

Lateral border: Cephalic vein and deltoid branch of the thoracoacromial artery (in the deltopectoralsulcus). Know the structures of the deltopectoral sulcus.

Medial border: At the inferior part of the region, lies the basilic vein (foramen on the brachial fascia:

basilic hiatus) and the medial antebrachial cutaneous nerve

The brachial fascia covers the flexor muscles of the arm and sends two septa-- medial and lateral

intermuscular septa (separates flexors from extensors). They divide the arm into two compartments;

flexor and extensor.

Removing the fascia, we will find the flexors, namely the biceps brachii (the long head is lateral and

the short head is medial). Below the biceps are the brachialis and the coracobrachialis. Behind thebiceps, the musculocutaneous nerve pierces through the coracobrachialis and is located between the biceps

and the brachialis muscles. Its end branch is the lateral antebrachial cutaneous nerve that accompanies the

cephalic vein in the forearm.Brachialis function: flexion and a little supination of the elbow joint and arm.


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Coracobrachialis function: flexion and adduction of the arm.

The main structures of the brachial region are found in the medial bicipital groove: the median nerve,

ulnar nerve, medial brachial and antebrachial cutaneous nerves, and the brachial artery. Branches of the

brachial artery are found in this region: 1)Profunda brachii artery accompanies the radial nerve (and gives

middle collateral and radial arteries), 2)Superior and inferior ulnar collateral arteries.

The superior ulnar collateral artery accompanies the ulnar nerve. The Median nerve crosses the

brachial artery in the brachial region. It is the most medial structure in the cubital fossa.

ANTERIOR CUBITAL REGIONSuperior: two fingers above the cubital fold (sulcus),

Inferior: two fingers below the cubital fold,

MedialandLateral: medial and lateral margins of the arm (med & lat epicondyles).

SUPERFICIAL STRUCTURES:Medial: the basilic vein together with the medial antebrachial cutaneous nerve.

Lateral: the cephalic vein together with the lateral antebrachial cutaneous nerve.

Between the basilic and cephalic veins, there is an anastomosis which is called the median cubital

vein (the network is "M" or "N" shaped). In clinics, blood is taken from this vein for examination. Be-

neath these structures lies the cubital fascia (continuation of brachial fascia). Below this fascia lie the

structures and muscles of the cubital fossa.

The cubital fossa is made by the flexors and extensors of the forearm. It is a V-shaped fossa (tri-

angular) that opens upward. The medial border of the fossa is formed by thepronator teres muscle andthe flexor muscles of the forearm. The lateral border is formed by the brachioradialis muscle and theextensors of the forearm. The basefloor of the fossa is formed by the brachialis muscle and lateral side

by thesupinatormuscle (surrounding the radius).

Structures of the fossa:

Lateral: tendon of the biceps

Middle: brachial arteryMedial: median nerve

In the cubital fossa, the brachial artery divides into two branches: the radial artery (which later gives the

radial recurrent artery) and the ulnar artery (giving the ulnar recurrent artery- anastomosing mainly with

the inferior ulnar collateral artery).

At the lateral side of the region lies the radial nerve. It is nota structure of the cubital fossa, but is astructure of the region. The radial nerve runs between the brachialis and the brachioradialis muscles.

In this region, the origins of the flexors (and some of the extensors) of the forearm can be seen.

Brachioradialis: Originates above the lateral epicondyle and inserts in the styloid process of theradius. It flexes the forearm (though it is in the extensor compartment). IF the forearm is pronated, it

supinates it until the middle position and vice versa ("saluting movement").

Extensor carpi radialis longus and brevis: Originate at the lateral epicondyle of the humerus and insertat the base of the 2nd and 3rd metacarpal bones. So, the origin of the extensors are included in this region.

ANTERIOR ANTEBRACHIAL REGION


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Superior: three fingers below the cubital sulcus

Inferior: a line along the styloid processes of the ulna and radius OR three fingers above the carpaleminence.

SKIN INNERVATION:

Medial and lateral antebrachial cutaneous nerves.


The basilic and cephalic veins. The medial and lateral antebrachial cutaneous nerves do not innervate

only the volar surface, but also the ulnar margin of the forearm and ulnar part of the dorsal surface. The

same for the lateral surface (radial).

The two veins originate from the dorsal carpal venous plexus (plexus venosus dorsalis manu). Deepto the antebrachial fascia, we find the flexor muscles. The brachioradialis muscle is seen at the radial

border of the region.

Structures of the region:

1) Ulnar nerve and artery, covered by the flexor carpi ulnaris. To see the superior 1/3 of the ulnar

artery, cut the superficial muscles.2)Radial artery andsuperficial branch of the radial nerve. They are covered by the brachioradialis

muscle. Underneath the flexor digitorum superficialis muscle, the medial nerve runs in the midline of the

region between the flexor digitorum superficialis and profundus. It is attached to the superficialis

(embedded in its fascia), so before cutting the flexor digitorum superficialis muscle, first dissect the nerve

and then cut the muscle

The median nerve innervates all the flexors except the flexor carpi ulnaris and flexor digitorum

profundus (the ulnar half). Deep to the flexor digitorum profundus, you can see the interosseous

membrane and the pronator quadratus, a quadrangular muscle between the radial margin of the radius and

the ulnar margin of the ulna. You will also see the anterior interosseous branch of the median nerve and

the anterior interosseous artery (from the common interosseous artery from the ulnar artery).

VOLAR CARPAL REGIONSuperior: level of the styloid processes

Inferior: level of the pisiform bone, three fingers above the carpal eminence.Medialand lateral: medial and lateral edges of the wrist.

SKIN INNERVATION:

End branches of the lateral and medial antebrachial cutaneous nerves and tiny cutaneous branches

from the median and ulnar nerves (not dissectable).


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Basilic and cephalic veins. Removing the fascia reveals the tendon of the palmaris longus (missing

10-20% of the time).

Order of structures from radial to ulnar:

1) Brachioradialis muscle (sometimes also extensor pollicis brevis and abductor pollicis longus.

2) Radial artery, together with two radial veins. We cannot see the superficial branch of the

radial nerve.

3) Flexor carpi radialis tendon.

4) Median nerve.

5) Palmaris longus (covers the median nerve, so sometimes is right above it).

6) Flexor digitorum superficialis muscle (4)

7) Ulnar artery and ulnar nerve.

8) Flexor carpi ulnaris muscle.

Carpal canal:

It is important to know the structures passing through the canal, especially the tendon sheathes. The

most superficial is the skin, then the veins and cutaneous nerves (between the fascia and the skin).

Removing the fascia reveals the arteries, nerves, and tendons. If all these are removed, we will find firstthe tendons of the flexor digitorum profundus and flexor pollicis longus. Cutting them exposes the

pronator quadratus.

So, the muscles are arranged in three layers, or four if you consider that the palmaris longus is alone

the most superficial muscle.

Structures passing through the carpal canal:

Median nerve

Flexor carpi radialis muscle in one tendon sheath

Flexor digitorum superficialis and profundus in another tendon sheath

Flexor pollicis longus muscle in its own tendon sheath

PALMAR REGIONInferior: roots of the fingers.

Medial: a line from the pisiform bone to the 5th finger or the medal border of the palm.Lateral: lateral border of the palm, (a line from the styloid process of the radius to the root of the

fingers).

Superior: radial and ulnar carpal eminences.

The most superficial layer is the aponeurosis palmaris (deep to the skin). It covers arteries, nerves,and tendons of the muscles. It covers the mesothenar space only. We don't have aponeurosis at the thenar

and hypothenar eminences-- only fascia.THE DIFFERENCE BETWEENA FASCIAANDAN APONEUROSIS: a fascia is just a thin sheath, an aponeurosis is

a tendon (or a continuation of a tendon). In the palm, the aponeurosis is the continuation of the

palmaris longus.

Below the aponeurosis, we have the superficial palmar arch formed by the ulnar artery and closed

by the superficial palmar branches from the radial artery. The ulnar artery passes over the carpal tunnel

(and not through) together with the ulnar nerve.

The radial artery turns around the base of the first metacarpal below the tendons of the abductorpollicis longus and the extensor pollicis brevis, and it arises in the foveola radialis (the anatomical snuffbox-- a triangular depression on the lateral side of the wrist that is bounded medially by the tendon of the

extensor pollicis longus and laterally by the tendons of the abductor pollicis longus and extensor pollicis

brevis). Then, it pierces through the 1st interosseous space (between the 1st and 2nd metacarpal bones) and

forms the deep palmar arch in the palm. The superficial palmar arch gives the common digital palmar

arteries (together with the common palmar nerves: 3 fingers from the median nerve, 1 fingers from the


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ulnar nerve).

The first and second fingers are supplied by theprinceps pollicis artery (from the deep palmar arch).The princeps pollicis gives three branches: one for the second finger (radial index artery) and two for the

first .

The deep palmar arch is closed by the deep palmar branch of the ulnar artery and gives palmar

metacarpal arteries that anastomose with the common digital palmar arteries. Together, they form the

proper digital palmar arteries. Proper palmar digital arteries are formed 2-3 cm above the root of the

fingers.

You should cut all the tendons of the muscles (flexor digitorum profundus and superficialis) in order

to seeinterosseous muscles,the deep palmar arch, andthe deep branch of the ulnar nerve. The

deep palmar arch is a tiny arch and not well visible.

One finger is supplied by two digital palmar nerves and the medical significance of this is Ober'sanesthesi: if you operate on the fingers, you should anesthetize both sides of the finger.

Tendon sheath: an outer, fibrous layer and an inner, synovial layer. The inner layer has a double layer

which is called vincula tendineum ormesotendineum. This is very important because blood vessels comethrough this sheath to supply the tendons. So, you must not lift the tendons during an opera

tion because you will destroy the arteries and the finger will be necrotized.

Inflammation of the tendon sheath is called phlegmon (an obsolete term for inflammation of subcu-

taneous connective tissue this phlegmon can spread onto the 1st finger through this tendon sheath-- in

this sheath, we don't have tendons of the 2nd, 3rd, and 4th fingers): from 5th to 1st and opposite.

Tendons of the 2nd, 3rd, and 4th do not have tendon sheaths at the palmar region. Their tendon sheaths

begin after the metacarpals.

In the palm, there are 3palmarand 4 dorsal interossei muscles. The palmar interossei are unipennate,and the dorsal interossei are bipennate. Unipennate muscles arise from one metacarpal and have the

tendon at one side. Bipennate muscles arise from two metacarpals.

Origin of the palmar interossei:

1st: ulnar surface of 2nd metacarpal.

2nd: radial surface of 4th metacarpal.

3rd: radial surface of 5th metacarpal.

Origin of the dorsal interossei:

1st: from 1st and 2nd metacarpal to 2nd extensor tendon.

Paralysis of the ulnar nerve: Metacarpophalangeal joints are extended and interphalangeal joints are alittle flexed-- clawhand.


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DELTOID REGION(Borders are the same as the deltoid muscle)

Anterior: the deltoidopectoral sulcusPosterior: the posterior border of the deltoid muscle.

SKIN

INNERVATION

:The lateral brachial cutaneous nerve (from the axillary nerve) and the lateral supraclavicular nerves

(innervating the shoulder covering the acromion and the surrounding part of the skin).

Just below the skin, we will find the deltoid fascia covering the deltoid muscle. Removing this fascia

exposes the deltoid. The anterior border of the region is the deltoidopectoral sulcus, containing the

cephalic vein and the deltoid branch of the thoracoacromial artery. The deltoid muscle is innervated by

the axillary nerve.

By cutting the deltoid, the main structures of the region can be seen: the Axillary nerve and the

Posterior circumflex humeral artery. These two structures pass through the quadrangular space (Hiatusaxillaris lateralis).

Borders of the lateral axillary hiatus:Superior: Teres minor

Inferior: Teres major

Medial: long head of Triceps

Lateral: Humerus

The posterior humeral circumflex artery is a branch of the third part of the axillary artery. The

axillary nerve is a branch of the posterior cord of the brachial plexus. You should know the origin and

insertion of the deltoid muscle.

To dissect, lift the muscle first to find the structures, then cut it (vertically to the fibers). There is a

bursa between the greater tubercle of the humerus and the muscle called the subdeltoid bursa.

Three muscles insert to the greater tubercle:supraspinatus, infraspinatus, and teres minor. Thecommon function of these three muscles is adduction and lateral rotation of the arm. The supraspinatusalso abducts the arm (because it covers the shoulder joint superiorly).

Latissimus dorsi, teres major, and subscapularis all rotate the arm medially. The latissimus dorsi is the

muscle that helps you to put your hand in your back pocket.

If you cut the deltoid muscle, you will see the lateral and medial axillary hiati and the long head of the

triceps that separates the two from each other.

Borders of the medial axillary hiatus (or triangular space):

Superior: Teres minor

Inferior: Teres major

Lateral: long head of the triceps (originating from the

infraglenoid tubercle of the scapula).

The circumflex scapular artery passes through this hiatus.


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POSTERIOR BRACHIAL REGIONInferior: three fingers above the olecranonSuperior: the posterior border of the deltoid regionMedialandLateral: medial and lateral margins of the arm.

SKIN

INNERVATION

:Lateral brachial cutaneous nerve (from axillary nerve), the posterior cutaneous branch of the radial

nerve, and the medial brachial cutaneous nerve.

Under the skin, we will find the brachial fascia that sends two septa. The fascia covers the triceps

muscle having three heads: medial, lateral, and long. Medial and lateral heads are found medial and

lateral to the sulcus nervi radialis.

If you cut the lateral head of the triceps, you will find the main structures of the region (located in the

sulcus nervi radialis of the humerus): the radial nerve and theprofunda brachii artery (from the brachialartery).

The branches of the profunda brachii artery are the radial and middle collateral arteries as well as

some muscular branches.

The radial nerve gives muscular branches innervating the triceps and cutaneous branches innervatingthe skin at this region.

POSTERIOR CUBITAL REGIONSuperior and inferior: three fingers above and below the olecranon.

Medial and lateral: along side the medial and lateral epicondyles of the humerus.

SKIN INNERVATION:

Posterior brachial cutaneous nerve (from the radial nerve), and the medial and lateral brachial and

antebrachial cutaneous nerves.

After removing the skin, find the cutaneous nerves and the fascia (continuation of the brachial and

antebrachial fascia). Deep to the fascia are the muscles (extensors and flexors) arising from the medial

and lateral epicondyles of the humerus, and the insertion of the triceps muscle (olecranon process).

At the medial side of the region, the ulnar nerve is found in thesulcus nervi ulnaris accompanied by

the superior ulnar collateral artery (from the brachial artery). You should know which muscles originate

from the lateral epicondyle.

We can say that the supinator muscle is a continuation of the triceps muscle (the lateral head).

POSTERIOR ANTEBRACHIAL REGIONMedial and lateral: a line along the medial and lateral epicondyles of the humerus or the medial and

lateral borders of the forearm.

Inferior: styloid processes of the radius and ulna.Superior: three fingers below the olecranon.

SKIN INNERVATION:

Medial, lateral, and posterior antebrachial cutaneous nerves.

Removing the skin, we will find the posterior antebrachial fascia. After removing the fascia, you will

find the muscles arranged in two layers-- superficial and deep.Superficial: brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, extensor


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digiti minimi, and extensor carpi ulnaris.

If you cut the superficial layer, the main structures of the region can be seen: Deep branch of the

radial nerve, radial interosseous artery (from the common interosseous artery). These structures pierce the

supinator muscle, forming the SUPINATORCANAL.Deep: supinator, abductor pollicis longus, extensor pollicis brevis and longus, and extensor indicis.

The main structures in this region are the muscles. Also be able to describe the tendon sheathes of

these muscles (see below).

DORSAL CARPAL REGIONFirst, find the superficial structures between the skin and the fascia.


Superficial branch of the radial nerve, the dorsal branch of the ulnar nerve, the basilic and cephalic

veins. Then, the extensor retinaculum and the tendon sheaths should be discussed.

Describe and know the carpal synovial sheaths (6):

1) Abductor pollicis longus and extensor pollicis brevis.

2) Extensor carpi radialis longus and brevis.

3) Extensor pollicis longus.

4) Extensor digitorum and extensor indicis.

5) Extensor digiti minimi.

6) Extensor carpi ulnaris.

FOVEOLA RADIALISThis is located between the extensor pollicis longus (ulnar border) and the abductor pollicis longus

and extensor pollicis brevis (radial border).


Superficial branch of the radial nerve and the cephalic vein lie above the fascia. Below the fascia, we

find the radial artery.

The radial artery turns around the tendons of th abductor pollicis longus and extensor pollcis brevis

and arises in the foveola radialis. Beneath these two tendons, the radial artery gives the ramus carpi

dorsalis, and from this tiny branch, we have the dorsal metacarpal arteries which anastomose with the

common palmar digital arteries and give the dorsal and volar proper digital arteries, supplying the fingers.After dissecting the arteries, you should dissect the three tendons.


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DORSALIS MANUS REGIONFirst, we have to speak about the innervation (the most important in this region)

1) Superficial branch of the radial nerve

2) Dorsal branch of the ulnar nerve

You should find the dorsal branch of the ulnar nerve and the superficial branch of the radial nerve

together with the cephalic and basilic veins. These two veins arise from theplexus venosus dorsalismanus or the rete venosum dorsale manus (aka. the dorsal venous arch).Below the plexus, the fascia covers the tendons of the extensors and some short muscles.

Removing the fascia, you can find the tendons of the extensor digitorum muscle and the tendons of themuscles going to the thumb: abductor pollicis longus and extensor pollicis brevis (the radial border of theregion) and the tendon of the extensor pollicis longus.

Beneath the tendons, the dorsal interosseous muscles (four; bipennate) and the dorsal metacarpal

arteries from the ramus carpus dorsalis (coming from the radial artery) can be seen. Be prepared to speak

about the origin, insertion, and function of the interosseous muscles (dorsal). Here, there are

intertendineous connections between the extensor tendons.

Fingers do not belong to this region, but they must be known. Focus on the innervation, blood supply,

and the relationship between the tendons of the flexors and extensors.

DORSAL SCAPULAR REGIONSuperior: along the side of the acromion to the 7 th cervical vertebra.Medial: the midline of the body.

Inferior: along the side of the inferior angle of the scapula (transverse line).Lateral: a longitudinal line from the acromion.

SKIN INNERVATION:

Dorsal rami or the spinal nerves.

Removing the skin reveals a fascia covering the trapezius muscle . Know the origin and insertion ofthe trapezius. Below the trapezius, the latissimus dorsi muscle is found at the inferior part of the region aswell as the teres majormuscle.

Beneath the trapezius muscle, there are other muscles too, namely thesupraspinatus (above), theinfraspinatus (below), and the teres minor.

At the lateral border of the region, you can see the long head of the triceps (separating the triangular

and quadrangular spaces from each other).

The main structure of the region is the suprascapular artery which comes from the subclavian artery,

and passes through the region above the superior transverse scapular ligament. The suprascapular nerve

comes together with the artery passing through the superior scapular foramen (below the superior

transverse ligament). These two structures innervate the supraspinatus and infraspinatus muscles. Both

structures, after passing through the superior scapular foramen, pass through the inferior scapular foramen

to the infraspinous fossa.

In the neck of the scapula, there is an anastomosis between the suprascapular artery and the circumflex

scapular artery (from the median axillary hiatus). So finally, this is an anastomosis between the axillary

artery and the subclavian artery because the circumflex scapular artery comes from the axillary and the

suprascapular from the subclavian.

In the superior part of the region, you can see the levator scapulae muscle coming from the nuchal

region.

The dorsal scapular nerve innervates the levator scapulae (C3 & C4) and comes together with the

dorsal scapular artery.

The rhomboid muscles move the scapula backward and the levator scapulae elevates the scapula.


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The suprapiriform and infrapiriform hiatuses are the two parts of the greater sciatic foramen divided

by the piriformis muscle. Borders of the greater sciatic foramen are: superoanterior (greater sciatic

notch), posterior (sacrotuberal ligament), and inferior (sacrospinal ligament).

Structures passing through the suprapiriformis hiatus:

1) Superior gluteal artery.2) Superior gluteal nerve.

Structures passing through the infrapiriformis hiatus:1) Inferior gluteal artery.

2) Inferior gluteal nerve.

3) Sciatic nerve.

4) Posterior femoral cutaneous nerve.

5) Pudendal nerve.

6) Internal pudendal artery (from internal iliac).

Structures passing through the lesser sciatic foramen:

1) Obturator nerve.2) Inferior pudendal artery.

3) Pudendal nerve.

4) Tendon of the obturator internus.

If you cut the gluteus medius muscle, you can see thegluteus minimus muscle which originates

between the anteriorand inferior gluteal lines of the iliac bones. The function of the gluteus medius is

abduction of the hip joint. The movements are similar to the movements of the deltoid muscle: if the

anterior fibers act, it is a medial rotator; if the posterior fibers act, it is a lateral rotator, and if all of them

act together, it is an abductor.

If the gluteus medius acts on the pelvis, it balances the pelvis.

The gluteus minimus helps in abduction and in medial rotation.The obturator internus arises from the inner surface of the obturator foramen. The tendon of this

muscle passes through the lesser sciatic foramen and turns around the lesser sciatic notch. From the

notch, it runs forward and lateral. Its function is lateral rotation of the thigh. The tendon of the obturator

internus is surrounded by thegemellus muscles. They arise from the lesser sciatic notch, and they areinserted to the trochanteric fossa.

Below the gemellus muscles and obturator internus muscle, lies the quadratus femoris muscle, be-tween the tuber ischiadicum and greater trochanter (quadrangular shaped muscle).

Between the gluteus maximus and greater trochanter, find the trochanteric bursa.

POSTERIOR FEMORAL REGIONSuperior: gluteal line.

Inferior: three fingers above the popliteal sulcus.

Lateral: along the side of the trochanter major.

Medial: from the medial end of the gluteal sulcus to the medial epicondyle of the femur.

SKIN INNERVATION:

Posterior femoral cutaneous nerve.

Beneath the skin, there is a fascia which the fascia lata. This fascia surrounds the posterior femoral

cutaneous nerve. ITISTHEONLYPLACEWHEREACUTANEOUSNERVEISLOCATEDINSIDETHEFASCIA. Before

removing the fascia, dissect the nerve.

After removing the fascia, you can find the flexor muscles of the thigh, arising from the tuber


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ischiadicum, except the short head of the biceps femoris (medial lip of the linea aspera). The biceps

femoris runs to the lateral side of the femur, but the semitendinosus and semimembranosus run to the

medial side. The biceps is inserted to the head of the fibula, while the semitendinosus and semimem-

branosus insert to thepes anserinus, and then to the tibia.

Some sources recognize a singlepes anserinus into which the sartorius, gracilis, semitendinosus, and

semimembranosus insert. Others distinguish apes anserinus profundus, the insertion of the semimembranosus, and

apes anserinus superficialis, the insertion of the other three. One of the MRT questions asks about thep. a.

superficialis, so be familiar with both forms!

Between the muscles, the sciatic nerve lies exactly in the midline of the thigh. The sciatic nerve

innervates the flexors of the thigh and divides into the common peroneal(aka. fibular) nerve and the tibialnerve. This division is usually at the end of the region, but sometimes is higher.

The most superficial structure between the muscles is the sciatic nerve. Next, are the popliteal vein

and artery (usually we have vein-artery-nerve, but here is opposite) because the vein and the artery comefrom the adductor canal (through the adductor hiatus).

In the lower part of the region, the adductor hiatus is formed by the adductor magnus near the medialepicondyle of the femur. The muscle fibers are inserted to the medial margin of the femur. The tendon

and the muscle fibers form and arch-shaped hiatus which is the outlet of the adductor canal(leading to the

popliteal fossa).

Borders of the adductor hiatus:

Superior: muscle fibers of the adductor magnus.Lateral: Femur (medial border).Medial: tendon of the adductor magnus.

The femoral artery gives rise to theprofunda femoris artery that gives proliferating branches to supplythe flexor muscles and also the medial and lateral circumflex femoral arteries. The lateral supplies the

extensors and the medial supplies the adductors (together with the obturator artery).

POPLITEAL REGIONSuperior: three fingers above the popliteal sulcus.

Inferior: three fingers below the popliteal sulcus.Medial: along side the medial epicondyle of the femur.

Lateral: along side the lateral epicondyle of the femur.

SKIN INNERVATION:

Superior part of the region: Posterior femoral cutaneous nerve.

Inferior part of the region: Medial and Lateral sural cutaneous nerves.


Vena saphena parva (between the fascia and the skin).

The lateral and medial sural cutaneous nerves accompany the vena saphena parva ("small") andfinally form the sural nerve. The lateral comes from the common peroneal nerve and the medial from thetibial nerve. The sural nerve then goes behind the lateral malleolus and enters the dorsum of the foot

(giving the lateral calcanean branch and the lateral dorsal cutaneous branch to the little toe).

Deep to the popliteal fascia (continuation of the fascia lata), you can find the same structures seen in

the posterior femoral region: 1)common peroneal and tibial nerves, 2)popliteal vein, and 3)popliteal artery

(from lateral to medial).

The POPLITEALFOSSA is a diamond-shaped fossa covered by the popliteal fascia. The base-floor of thefossa is the popliteus muscle (below), the posterior part of the articular capsule of the knee joint (middle


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part), and the femur-popliteal fossa (above):

Superior and medial: semitendinosus and semimembranosus.

Superior and lateral: biceps femoris.

Inferior and medial: medial head of the gastrocnemius.

Inferior and lateral: lateral head of the gastrocnemius.

The popliteal muscle is the deepest muscle and comes from the lateral epicondyle of the femur. It

inserts to the popliteal line of the tibia.

The tibial nerve descends into the posterior crural region and innervates the flexors of the leg.

The peroneal nerve becomes superficial and turns around the neck of the fibula, goes below the origin

of the peroneus longus muscle, and divides into the superficial and deep peroneal nerves. Thesuperficialremains in the peroneal compartment and the deep goes to the extensor compartment to supply theextensor muscles.

Because of the place of the common peroneal nerve (superficial at the level of the neck of the fibula),

the injury of the nerve is very frequent; usually with the fracture of the fibula. The result of the injury of

the common peroneal nerve is the "horse foot" (patient cannot extend the foot)pes equinus +pes varus(peroneal muscles). Together (superficial and deep) =pes equinovarus.

POSTERIOR CRURAL REGIONSuperior: three fingers below the popliteal sulcus.

Inferior: a line connecting the medial and lateral malleoli.

Medial: a line from the medial epicondyle to the medial malleolus.

Lateral: a line from the lateral epicondyle to the lateral malleolus.

SKIN INNERVATION:

Medial and lateral sural cutaneous nerves + the sural nerve.

If you remove the skin, you will find the vena saphena parva together with the sural nerve (found in

the midline of this region and go behind from the lateral epicondyle). The vena saphena parva arises from

theplexus venosus dorsalis pedis and runs behind the lateral epicondyle to the posterior surface of the leg.The fascia is called the posterior crural fascia, and it sends two septa to the fibula: anterior and

posterior intermuscular septa. These septa form the peroneal compartment of muscles. The crural fascia

sends also another layer to the anterior surface of the tibia: the tibial septum. Between the tibial septum

and the anterior intermuscular septum, we have the extensor compartment. The posterior intermuscular

septum and the tibial septum form the flexor compartment.

Removing the fascia reveals the muscles of the triceps surae (medial and lateral heads of the gas-

trocnemius muscle and the soleus muscle) in the superficial layer. The soleus muscle arises from a

tendinous arch which is between the tibia and the fibula. Below this tendinous arch, we can see the tibial

nerve and the posterior tibial artery and vein (they are covered by the soleus muscle, so you have to cut

this muscle to see the main structures of this region).

THREE DEEP MUSCLES: the most lateral is theflexor hallucis longus, the middle one is the tibialis

posterior, and the most medial is theflexor digitorum longus. The tibialis posterior arises a little belowthe other two. So, in the uppermost part of the region, the flexor hallucis longus and the flexor digitorum

longus can be seen next to each other. There, the tibial nerve and the posterior tibial artery and vein, are

found between the flexor digitorum longus and the flexor hallucis longus. In the lower part of the region,

these structures can be found between the flexor hallucis longus and the tibialis posterior muscle.

The tibial nerve comes from the sciatic nerve and innervates the flexor muscles by muscular branches.

The posterior tibial artery gives a branch here, the peroneal artery. This artery goes below the flexor

hallucis longus muscle between it and the fibula (it supplies this muscle).The tibial nerve and posterior tibial artery go behind the medial malleolus and run to the sole. The

tibial nerve forms the medial and lateral plantar nerves, and the posterior tibial artery forms the medial


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and lateral plantar arteries.

The tibialis posterior muscle and the flexor digitorum longus cross each other approximately 3 fingers

above the medial ankle. So, after the crossing, the flexor hallucis longus remains the most lateral, the

middle becomes the flexor digitorum longus, and the most medial will be the tibialis posterior. The flexor

digitorum longus is the crosser, thus it will be the most superficial.

MEDIAL MALLEOLAR REGIONThis region is located between the medial malleolus and the calcaneus. Deep to the skin, the vena

saphena magna (in front of the medial malleolus) runs in the anterior margin of the region. The VSM is

found together with the saphenous nerve, but usually the saphenous nerve doesn't go down behind the

medial ankle.

The tendons are covered by the flexor retinaculum which keeps the tendons close to the bones. The

first tendon is the tibialis posterior tendon (exactly behind the ankle). The middle one is the flexor digi-

torum longus (crossing the tibialis posterior above the medial ankle). Then, we have the posterior tibial

artery, accompanied by the two psoterior tibial veins and the tibial nerve. The last structure is the tendonof the flexor hallucis longus muscle.

Here, there are tendon sheathes surrounding the three tendons.

LATERAL MALLEOLAR REGIONSUPERFICIAL STRUCTURES:

The vena saphena parve, coming from theplexus venosus dorsalis pedis and going behind the lateralmalleolus; the sural nerve (from medial and lateral sural cutaneous nerves).

The sural nerve goes behind the lateral malleolus and gives the lateral dorsal cutaneous nerve. Thisnerve innervates the skin of the lateral side of the foot and the lateral margin of the little toe.

Remove the fascia to expose the penoneus longus and brevis muscles. These are held down by the

superiorand inferior peroneal retinacula (forming and "X" or "Y" shape). Beneath the peroneal reti-nacula, in a common tendon sheath, are the long and short peroneus muscles. The peroneus brevis is

attached to the base of the 5th metatarsal, and the peroneus longus is attached to the base of the 1st

metatarsal and to the medial cuneiform (sulcus peronei longus). The peroneus longus is covered by the

long plantar ligament in the plantar region.

The two retinacula are connected to the lateral malleolus and to the calcaneus.

The main function of the peroneus longus is holding the foot. It makes an arch together with the

tibialis anterior muscle (inserting to the same place).

DORSAL PEDIS REGIONSuperior: a line connecting the medial and lateral malleoli.

Inferior: the root of the toes.

Medial: a line from the medial malleolus to the first toe or the medial margin of the foot.Lateral: a line from the lateral malleolus to the fifth toe or the lateral margin of the foot.

SKIN INNERVATION (the most important region for this!):

The superficial peroneal nerve enters the dorsal pedis region and divides into two branches: the medial

and intermediate dorsal cutaneous branches. The medial dorsal cutaneous nerve innervates the medialborder of the first toe, the lateral border of the second and the medial half of the third toe. The


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intermediate dorsal cutaneous nerve innervates the lateral half of the third toe, the fourth and the medial

half of the 5th toe. The lateral side of the fifth toe is innervated by the lateral dorsal cutaneous nerve

(coming from the sural nerve). The lateral side of the second toe and the medial side of the second toe are

innervated by digital branches of the deep peroneal nerve. So, there are four nerves innervating the dorsal

side of the foot.

The deep peroneal nerve becomes superficial from below the tendons of the extensor hallucis longus

and brevis.

Together with the cutaneous nerves, we have theplexus venosus dorsalis pedis from which the venasaphena magna + parva drain blood.

Beneath the superficial structures, lie the retinaculum extensorum superiorand inferior. The superiorextensor retinaculum is at the superior border of the region. The two retinacula hold down the extensor

tendons. The extensor tendons are the extensor hallucis longus muscle, the extensor digitorum muscle,

and the tendon of the peroneus tertius (inserting to the base of the fifth metatarsal).

This region also includes the extensor digitorum brevis and the extensor hallucis brevis. The tendonsof the extensor digitorum brevis are inserted to the middle phalanges of the lateral four toes. The extensor

digitorum longus tendons are inserted to the distal phalanges of the lateral four toes.

An important structure in this region is the dorsalis pedis artery. It comes from the midpoint of theline connecting the medial and lateral ankle toward the first interosseal space. You can palpate the artery

because it is on the cuneiform bone (you can palpate the pulse in the limbs from the radial artery,the

posterior tibial artery, andthe dorsalis pedis artery).

The dorsalis pedis artery will form the arcuate artery beneath the tendons which is closed by thelateral tarsal artery (from the anterior tibia). The dorsalis pedis artery pierces through the first interosseal

space and closes the plantar arch. From the anterior tibial artery, we have several malleolar branches to

supply the ankle joint:

Anterior: Medial and lateral malleolar arteries.

Posterior: Medial and lateral malleolar arteries.

From the arcuate artery, the dorsal metatarsal arteries arise and will give the proper plantar digital

arteries.


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SUBINGUINAL REGIONSuperior: a line along the inguinal ligament.

Inferior: a line along the sulcus gluteus (anterior).Lateral: a line from the anterior superior iliac spine.Medial: a vertical line from the pubic tubercle.

SKIN INNERVATION:

Anterior femoral cutaneous nerve, Lateral femoral cutaneous nerve (coming from the lumbar

plexus approximately one cm below the anterior superior iliac spine), Femoral branch of the geni-

tofemoral nerve, andIlioinguinal nerve.

The genitofemoral nerve arises from the lumbar plexus and divides into two branches: a)Genital, andb)Femoral. The genital branch passes through the inguinal canal, and the femoral branch passes through

the lacuna vascerum of the subinguinal hiatus, pierces through the fascia lata, and becomes superficial toinnervate a small part of the skin below the inguinal ligament.

The medial part of the region is innervated by the ilioinguinal nerve (passing through the inguinal

canal). Mainly, it belongs to the inguinal region, but a small part belongs to the subinguinal region.


Vena saphena magna (piercing through the fascia lata through the cribiform lamina which is called thehiatus saphenous). Together with the vena saphena magna, we have the superficial nerves at the same

level. Tiny arteries come out from the hiatus saphenous (superficial epigastric artery, superficialcircumflex iliac artery, and external pudendal artery).

The main part of the superficial epigastric artery is in the inguinal region, and the circumflex is be-

tween the two regions.

Right beneath the skin, we have inguinal lymph nodes located into two lines: one parallel to theinguinal ligament (superficial) and one parallel to the vena saphena magna (and deep, parallel to the

femoral vein and artery). So, the vertical line of the lymph nodes is in two layers, one superficial and one

deep. Both lines form a letter "T".

The lymph nodes parallel to the inguinal ligament collect lymph from: Anterior abdominal wall

(below the umbilicus),Gluteal region,Perineal region,External genitalia,Anal opening,

Vestibulum vaginae, andFundus of the uterus.

The lymph nodes parallel to the veins and artery (the vertical line) collect lymph from the lower limb.

Thefascia lata ensheathes three muscles: a)Sartorius, b)Gracilis, and c)Tensor fascia latae. On thefascia, there is a hiatus called the hiatus saphenous. Below the fascia, you will see the extensor musclesand the adductors: the sartorius, and quadriceps femoris (only the rectus femoris arises from the anterior

inferior iliac spine; all the vastus heads arise from the femur).

At the medial side of the region, you can see the first part of the adductor muscles: Adductor longus,

gracilis, and the pectineus.

The main structure of this region is thefemoral canal. Below the inguinal ligament, there is anopening called the subinguinal hiatus. It is formed by the inguinal ligament and by the iliac bone below

the anterior superior iliac spine, and the superior ramus of the pubic bone.

Borders: Superior and anterior (inguinal ligament-- fascia lata), Posterior (superior ramus of pubis and

the anterior superior iliac spine.

The iliopsoas muscle passes through this hiatus to the thigh, together with the femoral nerve. This

lateral compartment of the subinguinal hiatus is called lacuna musculonervosum and is separated from thelacuna vasorum (middle compartment) by the arcuate ligament orarcusiliopectineus. This is a tendinous

arch that comes from the inguinal ligament and goes to thepecten ossis pubis.The middle part is the lacuna vasorum having the femoral vein and artery inside. It is surrounded by a

fibrous sheath (a connective tissue sheath).

The most medial part is called the lacuna lymphatica (inlet of the femoral canal). Medially, it isbordered by the lacunar ligament that rounds the sharp angle (Tjanatmia p. 60). Inside this annulus


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femoralis (femoral ring), there is a lymph node called the lymphatic node of Rosenmller. This ring is

not exactly a foramen. It is covered by a septum: the FEMORAL SEPTUM, which is pierced by the lymph

vessels passing through the canal going to the abdominal cavity.

Walls of the femoral canal:

Lateral: Femoral vein.Medial: Pectineus muscle and pectineal fascia (covering the muscle).

Anterior: Fascia lata.Inlet: Femoral ring (covered by the femoral septum).

Outlet: Hiatus saphenous.

The femoral canal is a short canal, 3cm only, and it extends from the femoral ring (at the level of the

inguinal ligament) to the hiatus saphenous. The femoral canal is not a real canal. It is called a canal onlyif a hernia occurs (the small intestine or something from the abdominal cavity passing though the canal).

The femoral canal is filled with loose connective tissue and lymphatic vessels.

If you describe the femoral canal as an anatomical structure, you should say that it includes the

femoral artery and vein and the hernial canal. So, in this case, the femoral canal contains the femoral

blood vessels and lymph vessels inside. The borders are:Medial: Pectineus muscle.

Lateral: Iliopsoas muscle.

Both of them are covered by a fascia which continues with each other, becoming a fossa called the

iliopectineal fossa (triangular shaped fossa) containing the femoral vein and artery and the hernial canal

itself (at the medial part).

The FEMORALTRIANGLE is made by the sartorius muscle (lateral), the adductor muscles, and the inguinal

ligament. It contains the iliopectineal fossa (with the blood vessels and the hernia canal). The femoral

artery gives a branch here; the deep femoral artery (profunda femoris artery), that gives three branches:

Medial circumflex femoral artery (together with the obturator artery, supplying the adductors),

Lateral circumflex femoral artery (supplying the extensors of the thigh),

Perforating branches (supplying the flexors of the thigh).The medial circumflex femoral artery anastomoses with the obturator artery and the lateral circumflex

femoral artery, with the superior and inferior gluteal arteries.

The femoral nerve has anterior cutaneous branches that pierce the fascia lata and supply the skin. It

also has a long branch that goes inside the adductor canal called the saphenous nerve.

The adductor brevis is covered by the pectineus and the adductor canal.


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ANTERIOR FEMORAL REGIONSuperior: an anterior line from the gluteal sulcus,

Inferior: 2-3 fingers above the patella,Medial: a line from the gluteal sulcus to the medial epicondyle of the femur,

Lateral: a line from the greater trochanter to the lateral epicondyle.

SKIN INNERVATION:

Anterior femoral cutaneous nerves,Lateral femoral cutaneous nerves (lateral part of the region,

andObturator nerve (lower-medial part of the region)(LUMBAR).

Deep to the skin, you can find thefascia lata. Between the skin and the fascia, run the vena saphenamagna, cutaneous branches of the femoral nerve, and the lateral femoral cutaneous nerves. The venasaphena magna runs in the medial side of the region and ascends to the subinguinal region.

The lateral femoral cutaneous nerve comes about 1 cm below the anterior superior iliac spine, coming

from the sacral plexus.

If you remove the fascia lata, be aware that thesartorius muscle is ensheathed by the fascia togetherwith thegracilis and the tensor fasciae latae.

At the lateral side of the region is the iliotibial tract, the thickened lateral part of the fascia lata. It isinserted to the tibia from the iliac crest.

Removing the fascia, we will see the extensor muscles: QUADRACEPS FEMORIS (rectus femoris, vastus

lateralis, vastus intermedius, vastus medialis). The adductor group is medial to the extensor muscles. The

adductor longus, together with the sartorius and the inguinal ligament, form the femoral or subinguinal

triangle (previously discussed).

The main part of the pectineus is in the subinguinal region, so you will see only the inferior part of this

muscle. The adductor magnus is beneath the adductor longus and gracilis muscles.

Between the adductor muscles and the extensor muscles, we will see the adductor canal:

Walls:

Medial: adductor longus and magnus,

Lateral: vastus medialis,

Anterior: lamina vastoadductoria (connects the adductor longus andmagnus with the vastus medialis.

The adductor canal goes to the popliteal fossa and has the femoral vein and artery inside as well as the

saphenous nerve. The saphenous nerve pierces through the anterior wall through the laminavastoadductoria and joins the vena saphenous magna. The descending genicular artery also piercesthrough the lamina vastoadductoria and supplies the knee joint.

The outlet of the adductor canal is located in the popliteal fossa and is called the adductor hiatus.

The femoral artery has a branch here coming from the subinguinal region and is called the profunda

femoris artery (see above).

The main structure here is the adductor canal.


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ANTERIOR GENICULAR REGIONInferior: three fingers below the patella,Superior: three fingers above the patella,Medial: the line along the medial epicondyle,

Lateral: the line along the lateral epicondyle.

SKIN INNERVATION:

Anterior femoral cutaneous nerves (superior part), Obturator nerve (medial part), Saphenous

nerve (inferior part), and Lateral femoral cutaneous nerve (lateral part).

There are three groups ofbursae: a) suprapatellar bursae, b) prepatellar bursae, and c) infrapatellar

bursae. In the prepatellar group, there is a bursa right beneath the skin called the subcutaneous prepatellar

bursa (between the skin and the fascia). The next bursa is between the fascia and the tendon and is called

the subfascial prepatellar bursa. The third one is between the tendon and the patella and is called the

subtendineal prepatellar bursa.

To see the suprapatellar bursa, you must open the joint (so it won't be seen in a regional study).

Beneath the skin, you will find the quadriceps femoris muscle (the common tendon). The continu-

ation of the tendons of the four heads of the quadriceps femoris form the patellar ligament and the medialand lateral patellar retinacula. The patellar ligament is inserted to the tuberosity of the tibia and the

medial and lateral retinacula, to the medial and lateral condyles of the tibia.

The adductor magnus is inserted to the medial epicondyle, so at the medial part of the region, you will

see its tendon.

So, we will also see the descending genicular artery (from the genicular artery) coming from the an-

terior femoral region, the vena saphena magna, and the saphenous nerve.

Thepes anserinus is located at the medial part of the region (medial is the ligamentumpatellae) and isa triangular shaped tendon formed by the insertion of the sartorius, gracilis, and semitendinosus muscles.

The common function of these three muscles is medial rotation of the knee joint.

ANTERIOR CRURAL REGIONSuperior: three fingers below the patella,

Inferior: the line connecting the medial and lateral malleoli,Medial: a line connecting the medial epicondyle and the medial malleolus,

Lateral: a line connecting the lateral epicondyle and the lateral malleolus.

SKIN INNERVATION:

Saphenous nerve (in front),Lateral sural cutaneous nerve (lateral part),Obturator nerve (upper

and medial parts), andSuperficial peroneal nerve.

Removing the skin, we will find thefascia cruris. It gives a septum between the extensors andperoneus muscles (at the anterior margin of the fibula) and it also gives a septum at the posterior margin

of the fibula. These two are called the anterior and posterior intermuscular septa.


The vena saphenous magnus (at the medial part of the region) coming from the plexus venousdorsalis pedis if front of the medial ankle; Superficial peroneal nerve, coming out from the peroneal

compartment between the middle and inferior third of the region and divides into medial and intermediate

dorsal cutaneous nerves.

Below the fascia, you will see the extensor muscles and the peroneus muscles.

Extensors: Extensor digitorum (most lateral), tibialis anterior, and (deep to and between the first two)extensor hallucis muscles. The tibialis anterior arises from the tibia and the interosseous membrane, but


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the extensor hallucis longus muscle arises a little deeper than the extensor digitorum longus and tibialis

anterior. So, at the superior part of the region, only the tibialis anterior and the extensor digitorum longus

will be seen.

The deep peroneal nerve and the anterior tibial artery (with the two veins) between these two muscles.The deep peroneal nerve comes from the common peroneal nerve and pierces through the anterior

intermuscular septum (between peroneal muscles and extensor digitorum longus) to enter the anterior

compartment. In the inferior part of the region, the nerve, veins, and artery are located between the

extensor hallucis longus and the tibialis anterior muscles.

The anterior tibial artery gives muscular branches and also recurrent branches to supply the knee joint.

Peroneus muscles: Both originate from the lateral surface of the shaft of the fibula. Theperoneuslongus is superficial, has a shorter muscle body (but longer tendon), and inserts to the base of the firstmetatarsal and the medial cuneiform. Theperoneus brevis is deep, has a broader, thicker muscle belly,and inserts to the base of the fifth metatarsal. They are innervated by the other division of the common

peroneal nervethesuperficial peroneal nerve, which runs between the peronei and the extensor digi-torum longus.

PLANTAR REGIONSuperior: calcaneus,

Inferior: roots of the toes,Medial: medial border of the sole,

Lateral: lateral border of the sole.

You should use a knife to remove the skin (~1 cm) in this region. The skin in this region has adipose

compartments in the subcutaneous layer. These adipose compartments function as shock absorbers and

also as a protector for the nerves and arteries that are found in the sole.

Removing the skin, the next structure is the plantar aponeurosis, arising from the tuber calcanei and

covering the middle part of the plantar region. It sends two septa (medial and lateral intermuscular septa)which define medial, lateral, and middle groups of muscles. These groups are called lateral, intermediate,

and medial eminences (analogous to thenar, mesothenar, and hypothenar areas of the palm). The medial

and lateral eminences are covered by a fascia which is a continuation of the plantar aponeurosis.

Deep to the plantar aponeurosis, you can see the nerves and arteries of the plantar region that are

branches of the medial and lateral plantar arteries and of the medial and lateral planter nerves. The medial

plantar nerve innervates the medial 3 toes by common and proper digital planter nerves and the lateral

plantar nerve innervates the lateral 1 toes also by common and proper digital plantar branches

(analogous to palmar innervation). Both are branches of the tibial nerve.

Together with the nerves, there are the plantar arteries with the same names coming from the plantar

arch.

In the medial plantar sulcus (between the abductor hallucis and flexor digitorum brevis), find the

medial plantar artery and nerve. In the lateral plantar sulcus (between the flexor digitorum brevis andquadratus plantae), find the lateral plantar artery and nerve (and the first portion of the plantar arch).

The plantar arteries arise from the posterior tibial artery, and the plantar nerves arise from the tibial

nerve. The posterior tibial artery and the tibial nerve pass behind the medial ankle, and you should cut the

abductor hallucis to see them.

The first layer in the intermediate eminence is the aponeurosis plantaris, then the flexor digitorumbrevis. If you remove the flexor digitorum brevis, you will see the flexor digitorum longus muscle,

together with the lumbricals, and the quadratus plantae inserting in the tendons of the flexor digitorum

longus. The quadratus plantae corrects the movements of the flexor digitorum longus because thedirection of this muscle is a little medial to lateral, and the direction of the quadratus plantae is lateral to

medial.

The medial plantar artery supplies only the first toe and the medial side of the second toe. To revealthe next part of the plantar arch, cut the flexor digitorum longus. To see the last portion of the plantar


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arch, cut the oblique head of the adductor hallucis (arising from the base of the metatarsal bones and

covering the plantar arch). The transverse head arises from the heads of the 3rd, 4th, and 5th metatarsals.

Both the transverse and the oblique heads are inserted to the proximal phalanx of the 1st (big) toe.

The plantar arch is closed by the dorsalis pedis artery. This arch gives the common and proper digital

plantar arteries.

The lateral plantar nerve innervates the abductor and flexor digiti minimi, the adductor hallucis, the

quadratus plantae, the last 2 or 3 lumbricals, and all the interosei muscles.

In the last layer, you can find the interosseous muscles and the long plantar ligament above the in-

terosseous muscles, covering the tendon of the peroneus longus muscle.

Then, we can speak about the muscles of the medial and lateral eminences. In this region, the layers

of the muscles in the intermediate eminence are the most frequently asked. So:

1st layer: Aponeurosis plantaris,

2nd layer: Flexor digitorum brevis,

3rd layer: Flexor digitorum longus, lumbricals, and quadratus plantae,

4th layer: Adductor hallucis, interosseous muscles, and the long plantar ligament,

5th layer: Tendon of the peroneus longus muscle.

In the medial and lateral eminences, we don't have layers.

In the superior part of the region, the flexor digitorum longus crosses the flexor hallucis longus. Theflexor digitorum longus is the crosser (the same as in the posterior crural region).


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SKULL

The frontal bone has a frontal part called thesquama ossis frontalis and an orbital part which iscomposed by the orbital plane (or lamina) having a orbital surface (lower) and a cerebral (upper) surface.

The frontal lobe of the brain is located in the anterior cranial fossa on the cerebral surface of the orbital

plane. Between the orbital parts, the nasal part of the frontal bone forms the groove of the nasal cavity

(above the nasal bone, the roof of the nasal cavity; inside this part is the frontal sinus). The middle

portion, between the supraorbital lines (or above the supraciliary margins), is smooth and called the

glabella (it means smooth with no hair). The glabella is the anterior wall of the frontal sinus, so the sinus

can be reached by piercing it. The frontal sinus opens into the nasal cavity.

Paranasal sinuses are located around the nasal cavity and open into it. They are filled by air and lined

by mucous membrane on the inner surface. One of these sinuses is thefrontal sinus that has a processwhich is called zygomatic process. It is attached to the frontal process of the zygomatic bone.

Between the orbital lamina and behind the nasal part, lies the ethmoid bone. It has the cribiform plate

(or lamina) and the crista galli. The lamina cribrosa forms the horizontal plate of the ethmoid bone,making it a T-shaped bone. The continuation of the crista galli below the cribiform plate is the

perpendicular plate which forms theseptum nasi (the vomer joins the perpendicular plate to form the main

inferior-posterior part of the nasal septum). Thus, the nasal septum contains two bones.

The ethmoid bone has another lamina which is the orbital lamina (orlamina papyracea: thin likepaper). One more surface covers the air cells (cellule ethmoidale) that communicate with each otherforming a sinus called the ethmoid sinus. This sinus also opens into the nasal cavity.

If someone suffers an inflammation in these sinuses, the voice will be changed (hose-like sound).

These air cells are between the orbital cavity and the nasal cavity. They are separated from the orbital

cavity by the orbital lamina of the ethmoid bone and from the nasal cavity by this rough surface of theethmoid bone to this nasal surface which is not a straight place, but a rough surface. To this nasal surface,

the two nasal conchae (superior and middle nasal conchae) attach. It is easier to understand in a frontal

section through the sinuses.

The concha nasalis inferioris a separate bone, and it is attached to the maxilla and the palatine bone.

The concha nasalis media and c. n. superiorarise from the nasal surface of the perpendicular plate of the

ethmoid. The superior concha is very short, and you can find it only in the posterior part of the nasal

cavity. The middle and inferior concha are much longer.

The meatus nasi superiorand meatus nasi media are between the conchae and the ethmoid bone.Below the concha inferior, there is a meatus nasi inferior.

The maxilla has a maxillary sinus and a maxillary hiatus opening into the middle nasal meatus. Apart of this maxillary hiatus is covered by the concha (by the maxillary process of the inferior nasal

concha). If the inferior nasal concha is attached to the maxilla, the hiatus is just a tiny opening. This

opening (hiatus maxillaris) is on the superior part of the sinus. If there is fluid inside, it cannot come outbecause the opening is at the top of the maxillary sinus (the patient should stand upside down for the fluid

to drain out). That's why infection of this sinus is so frequent. From the frontal sinus, infected fluid

simply flows out and downward into the maxillary sinus.

The cribiform plate is between the orbital plates of the frontal bone.

Behind the frontal bone, lies the sphenoid bone. Its main parts are the lesser wings, the greater wings,

and the body. The greater wing has different surfaces: Cerebral surface (related to the temporal lobe of

the cerebrum in the middle cranial fossa),Temporal surface,Infratemporal surface (the borderbetween the temporal and infratemporal surfaces is the infratemporal crest, at the level of the zygomatic

arch),Orbital surface.


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The pterygoid process has two lamina: lateral and medial, and a body forming thesella turcica(Turkish saddle). The middle of the sella is the hypophesial fossa. The Turkish saddle connects the two

middle cranial fossae in the midline.

Between the ala minor and major ("wings"), there is fissure called thesuperior orbital fissure. Thereis also an inferior orbital fissure (if you look inside the orbital cavity). The superior orbital fissureconnects the orbital cavity with the middle cranial fossa, and it contains the cranial nerves III, IV, V

3

, &

VI and the superior ophthalmic vein (taking blood into the cavernous sinus, which is lateral to the Turkish

saddle).

DURAL SINUSES:The main veins of the brain inside the skull are different from the veins in the periphery, outside the

skull. The difference is that the wall of these veins is formed by dura mater. There is an important ve-

nous sinus which is calledsinus cavernosum. It is extremely important for two reasons: 1) the motor nerveof the eye, the ophthalmic nerve, and the internal carotid artery pierce through this sinus, going to thesuperior orbital fissure, 2) the superior ophthalmic vein (from the orbital cavity) has an anastomosis with

the facial vein (main vein of the face), and this anastomosis is here in the medial angle of the eye. An

infection from the face could be spread through the ophthalmic vein into the cavernous sinus, and the

result could be paralysis of the eye (because of the location of the motor nerve of the eye). This vein (theanastomosis) is called the angular vein because it is at the medial angle of the eye.

Behind the superior orbital fissure, there is a round-shaped foramen called theforamen rotundum.Through this foramen, the 2nd branch of the trigeminal nerve (maxillary nerve) passes. The foramen

rotundum leads to the pterygopalatine fossa.

Behind, there is an oval-shaped foramen called theforamen ovale. [Foramen rotundum is just behindthe fissure, and foramen ovale is a little behind and lateral.] The foramen ovale transmits the mandibular

nerve. Medial tof. ovale, there is an emissary foramen that is for veins connecting the inner surface of theskull with the outer surface (accessory meningeal vein). In some skulls, this foramen is missing.

Posterior and lateral to the oval foramen, theforamen spinosus transmits the middle meningeal artery,which is the main artery of the dura matter (outermost membrane of the skull). Thesulci arteriosi is for

the middle meningeal artery. Thesulci arteriosi is also called the sulcus of the middle meningeal artery.These sulci start from the spinous foramen.

There is another tiny nerve; the meningeal branch of the mandibular nerve (not so important). The

spinous foramen is called that because this tiny posterior apex of the ala major is calledspina ossissphenoidalis.

The temporal bone is irregularly shaped, and consists of two main parts: pars petrosa and pars

squamosa. The squamous part This pyramid is the part of the petrous temporal (pars petrosa) because of

the shape. The pyramid is the main part of the petrous temporal. The other part is the mastoid-styloid

part.

Between the pyramid and the sphenoid bone, there is a big foramen called theforamen lacerum. Thisforamen is not a real foramen in the living skull, because it is covered by a fibrous tissue membrane. It is

just a foramen in the bony skull. In this foramen, there are fissures for two tiny nerves: greater and lesser

petrosal nerves (coming out from the pyramid sheath). On the anterolateral surface of the pyramid, we

have two tiny hiatus called hiatus canalis nervi petrosi majoris and h.c.n. minoris. These sulci go on theanterior surface of the pyramid, and they go out through the foramen lacerum. Medial to the foramen

lacerum, there is a sulcus (on the lateral side of the sella turcica) called the carotid sulcus, for the inner

carotid artery. The artery comes into the skull through the carotid foramen which is inside the pyramid.

The inlet is called the carotid foramen. The internal carotid artery arises in the skull making the sulcus

caroticus. Then, it runs through the cavernous sinus and divides into end branches, giving the ophthalmic

artery and the middle + anterior cerebral arteries for the brain. THECAROTIDCANALISTHEMOSTIMPORTANT

STRUCTUREOFTHESKULL.

The Turkish saddle (sella turcica) is bordered anteriorly by thesulcus prechiasmatis (chiasmatic

sulcus) and posteriorly by the tuberculum sellae. The two ends of this tubercle form two tiny clinoidprocesses which are called the middle clinoid process. The two ends of the dorsum sellae form theposterior clinoid processes. The back of the sella turcica is called the dorsum sellae (normally is ele-


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vated). The middle of the sella is called the hypopheseal fossa. The clinoid processes are important

because they point to the hypopheseal fossa.

On the pyramid, the arcuate eminence (eminentia arcuata) is formed by the anterior semicircularcanal of the inner ear. Lateral to the eminentia arcuata and a little anterior, a very thin wall called tegmentympani forms the roof of the tympanic cavity. An infection can be spread into the cranial cavity throughthe thin wall. The tegmen tympani has a process downward which is not visible because it is inside the

pyramid and is called the tegmental crest. This crest separates the squamous part from the tympanic part

(because the crest belongs to the petrous part of the temporal part). So, there are two fissures here. One is

between the tympanic and petrosa, called thefissura petrotympanica, and the other is between the petrosa

and squamous part, called thefissura petrosquamosa . The pterygotympanic fissure is more importantbecause the chorda tympani nerve (from the facial nerve) passes through.

In the superior margin of the petrosa bone is the sulcus for the sinus petrosus superior. This sinus

drains blood from the cavernous sinus into the sigmoid sinus.

At the apex of the pyramid, therer is an impression on the anterior surface called the trigeminal

impression (for the trigeminal ganglion). The trigeminal nerve divides into its three branches at this level.

The MIDDLECRANIALFOSSA is composed of the greater wing of the sphenoid (ala major), the

anterolateral surface of the pyramid of the temporal bone, and the squama of the temporal bone.

The POSTERIORCRANIALFOSSA is formed by the posteromedial surface of the pyramid, the basilar part of

the occipital bone (also called the clivus - "slope"), the lateral part of the occipital bone, and the squama of

the occipital bone. The borderline between the middle and posterior cranial fossae is thesulcus sinuspetrosis superioris and the dorsum sellae. Posteriorly, it is thesulcus sinus transversi. If you cut thecalvaria of the skull, cut it right above the external occipital protuberance.

The posterior cranial fossa is a closed fossa. It is closed by a dura in the horizontal plane which is a

double layer of the dura matter, called the tentorium cerebelle. This tentorium separates the cerebellumfrom the occipital lobe of the cerebrum. The tentorium cerebelle is inserted to the sulcus sinus transversi

and to the sulcus sinus petrosi inferior. It has a notch called the tentorial notch (insisura tentorii) for themesencephalon brain, the pons, and the medulla.

Theporus acusticus internus goes into the meatus acusticus internus. The meatus acusticus internushas a ganglion inside. The facial nerve and the vestibulocochlear nerve pass through the porus acusticus

internus. Then, they divide in the floor of this meatus which is thefundus acusticus interni. Also, the

labyrinthine artery passes through on its way to the labyrinth (inner ear). So finally, we have: porus a.i.

meatus a.i. fundus a.i. division of the nerves.

The vestibulocochlear nerve goes to the labyrinth (for the vestibule and the cochlea), and the facial

nerve goes inside the facial canal which is also inside the pyramid bone. The first part of the facial canal

is vertical and perpendicular to the axis of the pyramidal bone (it is inside the bone). After this, the canal

turns backward and goes parallel to the axis of the pyramidal bone. This is the external genu of the facial

canal. The hiatus canalis nervi petrosi majoris starts at the genu of the facial canal because the nervecomes out of the facial canal. After this second part of the canal, is goes downward. This is the

perpendicular part, and it comes out through the stylomastoid foramen. So, this foramen is the outlet of

the facial canal. Here, the facial nerve also gives a branch from the descending part which is the chordatympani. It goes into the tympanic cavity and comes out through the petrotympanic fissure. The inlet ofthe facial canal is the fundus of the internal acoustic meatus.

The apertura externa aqueductus vestibuli is right behind theporus acusticus internus below thisarcuate eminence. (There are three semicircular canals: anterior, posterior, and lateral; that belong to the

vestibular organ [sensitive for the angular movement of the head]. The anterior canal makes the arcuate

eminence). Above the pore, we have the subarcuate fossa. More important is thejugular foramen. It is

an "8"-shaped foramen. The intrajugular process separates them into anterior and posterior foramina.

The jugular foramen is between the lateral part of the occipital bone and the petrous part of the

temporal bone. The anterior part of the foramen transmits the glossopharyngeal, vagus, and accessory

nerves (CN IX, X, XI). The posterior part transmits the internal jugular vein, which is the continuation ofthesulcus sinus transversi. This is the internal occipital protuberance, the crista occipitalis interna, andthe sulcus sinus sagitalis superioris from the calvaria.


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Another very important canal is the hypoglossal canal crossing the occipital condyle. It is an oblique

canal which crosses the occipital condyle through the lateral part of the occipital bone. It runs from

posteromedial to anterolateral. It transmits the hypoglossal nerve (CN XII).

There is another canal called the condylar canal. It is parallel to the occipital condyle. It transmits the

emissary veins. Sometimes, it doesn't exist. Sometimes, it is very small.

Through theforamen magnum, the following structures pass through (most important): spinal cord(medulla oblongata), vertebral artery, spinal root of the accessory nerve, anterior and posterior spinal

arteries, a tiny branch of the meningeal artery, and the spinal origin from the upper part of the spinal cord.

EXTERNAL SURFACE OF THE SKULLThe nasal bone forms the bony part of the anterior wall of the nose.

The maxilla has 4 processes and a body. The body has a cavity called the maxillary sinus. The four

processes are 1)Frontal, 2)Palatine, 3)Zygomatic, 4)Alveolar. The shape of the body is pyramidal or

tetrahedral. The anterior surface of the maxilla has thefossa canina (name comes from dogs where it is

very large). It also has the orbital surface, the infratemporal surface (having the tuber maxillae), and thenasal fossa with the hiatus of the maxillary sinus.

The zygomatic bone has a temporal process which helps form the zygomatic arch (with the zygomatic

process of the temporal bone). It has three surfaces: Orbital, temporal, and lateral.

The zygomatic canal is a Y-shaped canal. Its inlet is theforamen zygomatico-orbitale. Its two outletsare theforamina zygomaticofaciale andzygomaticotemporale. The canal divides into two parts inside thezygomatic bone and transmits the zygomatic nerve (branch of the maxillary nerve) innervating a part of

the face above the zygomatic bone.

The vomer, which is the posteroinferior part of theseptum nasi, forms two tiny wings called the alaevomerum. They are attached to the inferior surface of the body of the sphenoid bone.

The palatine bone is an L-shaped bone, having a perpendicular plate and a horizontal plate. Theperpendicular plate divides into two processes (sphenoidal and orbital). The first is attached to the body

of the sphenoid bone, and the second forms a part of the inferior wall of the orbital cavity. Between them,

there is a notch called the sphenopalatine notch (incisura). This notch is the inferior border of thesphenopalatine foramen (or fossa). The superior border is the inferior part of the body of the sphenoid

bone. This foramen connects the pterygopalatine fossa with the nasal cavity. The horizontal part of the

palatine bone forms the posterior part of the hard palate. The pyramidal process is between the pterygoid

process and the maxilla. The conchal crest is where the inferior nasal concha is attached to the maxilla

and palatine bone.

The lacrimal bone is an oval-shaped bone right behind the frontal process of the maxilla. It has a

posterior lacrimal crest and an anterior lacrimal crest on the maxilla. Between these two crests, there is a

fossa called thefossa sacci lacrimalis (fossa for the lacrimal sac). We have also the lacrimal canal thatleads to the inferior nasal meatus (tears drain to the nasal cavity through this canal). Inferior nasal concha

is a separate bone which is attached to the maxilla and the palatine bone.

The pterygoid process has two lamina: medial and lateral lamina of the pterygoid process. The medial

process forms a hook called the hamulus pterygoideus. The tendon of the tensor veli palatini muscle isattached there. If you follow the medial lamina (root), you will find the scaphoid fossa that continues

lateral and backward to thesulcus tubae auditivae, which in turn continues to the canalis musculotubarius(containing the auditory tube and tensor tympani muscle).

With the auditory tube, the pressure of the ear is equalized because the tympanic cavity is closed to its

one end by the tympanic membrane. So, the air communicates with the pharynx through this tube.

The lower part of the canalis musculotubarius goes into the tympanic cavity.

Theforamen ovale andspinosum connect the middle cranial fossa with the outer surface of the skull.

At the root of the pterygoid process, there is a canal called the pterygoid canal. This leads to thepterygopalatine fossa. The greater petrosal nerve comes out from theforamen lacerum, then goes into thepterygoid canal, arising in the pterygopalatine fossa. Inside the fossa, there is the pterygopalatine


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ganglion. So, the greater petrosal nerve takes the preganglionic fibers to the ganglion.

The pharyngeal tubercle is at the outer surface of the skull. The pharynx is behind the nasal cavity

and behind the oral cavity. It has posterior and lateral walls, but no anterior wall, because anteriorly, it

communicated with the nasal cavity, oral cavity, and larynx.

The carotid foramen is the inlet of the carotid canal.

The tegmental crestseparates two fissura: petrotympanic and petrosquamosa.Lateral to the jugular foramen, we have the jugular fossa for the internal jugular vein.

Between the carotid foramen and the jugular foramen, there is a tiny fossa called thefossapetrosa.The canaliculi tympanici runs in this fossa, and then goes into the tympanic cavity. It transmits thetympanic nerve (from the glossopharyngeal). When this nerve comes out from the tympanic cavity, it is

called the LESSERPETROSALNERVE. The GREATERPETROSALNERVEis a branch of the facial nerve. Thesulcus nervipetrosi majoris comes out from the facial canal. Thesulcusnervi petrosi minoris comes out from thetympanic cavity. There is another tiny opening on the margin of the pyramidal bone, below theporus

acusticus internus. This is the apertura externa aqueductus vestibuli (or cochleae). Two openings arefound in the fossula petrosa (1canaliculus tympanicus and 2apertura externa aqueductus cochleae).

On the wall of the carotid canal, there are tiny canaliculi called the canaliculicaroticotympanici.Theforamen stylomastoidea is the outlet of the facial canal. The incisura mastoidea is lateral to the

sulcus arteriae occipitalis (for the occipital artery, which is a branch of the external carotid artery).

The

kovacs anatomy

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