Human anatomy



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KOVÁCS NOTES

OF

HUMAN ANATOMY



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) which continues 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 the pectoralis major muscle.

The pectoralis minor muscle lies deep to the pectoralis 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 thora­codorsal arteries.

The axillary vein is medial to the axillary artery which is surrounded by the cords of the brachial plexus.
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: C7

Inferior 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 the brachialis 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).
The Median 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, it goes through the carpal canal. In the palmar region, it is covered by the pal­maris longus tendon. If this muscle is missing, the nerve runs between the flexor carpi radialis tendon and the flexor digitorum 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 3½ 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 the sulcus nervi ulnaris. Then, it reaches the forearm between the two heads of the flexor carpi ulnaris muscle. In the inferior 1/3 of the forearm, we can find the ulnar nerve covered by the flexor digitorum 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 deep branch innervates the interossei muscles, the 3rd and 4th lumbricals, the adductor pollicis, and the hypothenar muscles. The superficial branch innervates the ulnar 1½ fingers, the ulnar 1/2 of the palm, and the palmaris brevis.


The medial brachial and 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 the brachial 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).
The Radial nerve arises from the posterior cord of the brachial plexus. It is located in front of the tendon 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 2½ fingers (by digital nerves) and skin at the dorsal side of the hand. The deep branch pierces through the superficial muscles (supinator) and innervates the extensor muscles.


The Axillary nerve arises from the posterior cord of the brachial plexus and gives skin branches (lateral cutaneous branches) that are not dissectable.

AXILLARY REGION

The 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 skin

Inferior: Anterior axillary fold

The axillary fossa pyramid-shaped fossa. Its base is open, but it is defined by the anterior and 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.
Origins and Insertions:

Biceps: Supraglenoid tubercle  Tuberosity of radius

Coracoid process



Coracobrachialis: Coracoid process  middle of the shaft of the humerus

Brachialis: Lower half of humerus  Condyloid process of ulna

ANTERIOR BRACHIAL REGION

Superior: 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 deltopectoral sulcus). 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 the biceps, 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.

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 REGION

Superior: two fingers above the cubital fold (sulcus),

Inferior: two fingers below the cubital fold,

Medial and Lateral: 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. Be­neath 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 (tri­angular) that opens upward. The medial border of the fossa is formed by the pronator teres muscle and the flexor muscles of the forearm. The lateral border is formed by the brachioradialis muscle and the extensors of the forearm. The basefloor of the fossa is formed by the brachialis muscle and lateral side by the supinator muscle (surrounding the radius).


Structures of the fossa:

Lateral: tendon of the biceps

Middle: brachial artery

Medial: 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 not a structure of the cubital fossa, but is a structure 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 the radius. 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 insert at the base of the 2nd and 3rd metacarpal bones. So, the origin of the extensors are included in this region.

ANTERIOR ANTEBRACHIAL REGION

Superior: three fingers below the cubital sulcus

Inferior: a line along the styloid processes of the ulna and radius OR three fingers above the carpal eminence.
Skin Innervation:

Medial and lateral antebrachial cutaneous nerves.


Superficial Structures:

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). Deep to 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 and superficial 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 REGION

Superior: level of the styloid processes

Inferior: level of the pisiform bone, three fingers above the carpal eminence.

Medial and 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).



Superficial Structures:

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 first the 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 REGION

Inferior: 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 Between a Fascia and an 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 abductor pollicis longus and the extensor pollicis brevis, and it arises in the foveola radialis (the anatomical snuff box-- 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: 3½ fingers from the median nerve, 1½ fingers from the ulnar nerve).

The first and second fingers are supplied by the princeps 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 see interosseous muscles, the deep palmar arch, and the 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's anesthesi: 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 or mesotendineum. This is very important because blood vessels come through 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 subcu­taneous 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 3 palmar and 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 a little flexed-- clawhand.

DELTOID REGION

(Borders are the same as the deltoid muscle)



Anterior: the deltoidopectoral sulcus

Posterior: 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 (Hiatus axillaris 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. The common function of these three muscles is adduction and lateral rotation of the arm. The supraspinatus also 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.



POSTERIOR BRACHIAL REGION

Inferior: three fingers above the olecranon

Superior: the posterior border of the deltoid region

Medial and Lateral: 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 the profunda brachii artery (from the brachial artery).

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 innervat­ing the skin at this region.



POSTERIOR CUBITAL REGION

Superior 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 the sulcus 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 REGION

Medial 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 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 supinator canal.



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 REGION

First, find the superficial structures between the skin and the fascia.


Superficial Structures:

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 RADIALIS

This is located between the extensor pollicis longus (ulnar border) and the abductor pollicis longus and extensor pollicis brevis (radial border).


Superficial Structures:

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.

DORSALIS MANUS REGION

First, 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 the plexus venosus dorsalis manus 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 the muscles going to the thumb: abductor pollicis longus and extensor pollicis brevis (the radial border of the region) 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 REGION

Superior: along the side of the acromion to the 7th 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 of the trapezius. Below the trapezius, the latissimus dorsi muscle is found at the inferior part of the region as well as the teres major muscle.

Beneath the trapezius muscle, there are other muscles too, namely the supraspinatus (above), the infraspinatus (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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