axilla & upper limb

AXILLA & UPPER LIMB

Kaan Yücel M.D, Ph.D. 31. March. 2014 Monday

AXILLA (ARMPIT)

Gateway to the upper limb

An area of transition between the neck and the arm.

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BLOOD COMESARTERIESBLOOD GOESVEINSMUSCLES,VESSELS, SWEAT GLANDS INNERVATEDNERVES

Contents of the axillaAxillary artery and its branchesAxillary vein and its tributariesLymph vessels and lymph nodesBrachial plexus

These structures are embedded in fat.

Axillary arterySupplies the walls of the axilla & related regions.

Before: Subclavian artery After: Brachial arteryFrom lateral border of 1st rib

to Inferior border of teres major

a somatic nerve plexus - upper limbformed by intercommunications among ventral rami of

lower 4 cervical nerves ( C 5 - C 8) & T 1responsible for motor innervation to all of muscles of upper limb exception trapezius.

BRACHIAL PLEXUS

supplies all of the cutaneous innervation

of the upper limb exception area of the axilla (armpit)

(intercostobrachial nerve)

an area just above the point of shoulder (supraclavicular nerves)

dorsal scapular area (cutaneous branches of dorsal rami)

BRACHIAL PLEXUS

communicates with the sympathetic nervous system..

begins in the neck and extends into the axilla.

Almost all branches of the brachial plexus arise in the axilla (after the plexus has crossed the 1st rib). "Randy Travis Drinks Cold Beer"RootsTrunksDivisionsCords

Branches· Alternatively: "Read The Damn Cadaver Book!"· Alternatively: "Real Texans Drink Coors Beer".

The parts of the brachial plexus, from medial to lateral, are roots, trunks, divisions, and cords.

All major nerves that innervate the upper limb originate from the brachial plexus, mostly from the cords.

C5

C6

C7

C8

T1

Superior trunk

Inferior trunk

Middle trunkLateral cord

Posterior cord

Medial cord

Lateral pectoral nerveMusculocutaneous nerveLateral root of median nerve

Sup. & Inf. Subscapular nervesThoracodorsal nerveAxillary nerveRadial nerve

Medial pectoral nerveMedial cutaneous nerve of armMedial cutanoues nerve of forearmUlnar nerveMedian nerve

Suprascapular nerveThe nerve to subclavius muscle

Dorsal scapular nerveLongThoracİcnerve

Red: Anterior divisionBlue: Posterior division "Randy Travis Drinks Cold Beer"Roots

TrunksDivisionsCords

Branches· Alternatively: "Read The Damn Cadaver Book!"· Alternatively: "Real Texans Drink Coors Beer".

Region of upper limb attachment to the trunk Proximal segment of limb overlaps parts of the trunk (thorax and back) and lower lateral neck.

includes Pectoral ScapularDeltoid regions of the upper limblateral part (greater supraclavicular fossa) of lateral cervical region. Overlies half of the pectoral girdle.

SHOULDER

The pectoral (shoulder) girdle formed by:Scapulae and clavicles completed anteriorly by the manubrium of the sternum (part of the axial skeleton).

SUPERFICIAL POSTERIOR AXIOAPPENDICULAR MUSCLES

EXTRINSIC SHOULDER MUSCLESTrapezius & latissimus dorsi

DEEP POSTERIOR AXIOAPPENDICULAR MUSCLESEXTRINSIC SHOULDER MUSCLESLevator scapulae & rhomboids

SCAPULOHUMERAL (INSTRINSIC SHOULDER) MUSCLES

6 scapulohumeral muscles Deltoid, teres major, supraspinatus, infraspinatus, subscapularis, and teres minorpass from scapula to humerus Act on the glenohumeral joint.

All the intrinsic muscles but the deltoid and the subscapularis are muscles of the posterior scapular

region.

4 musclespass between the scapula and proximal end of humerus:SupraspinatusInfraspinatusTeres minorTeres major

POSTERIOR SCAPULAR REGION

+ part of long head of the triceps brachii, passes between the scapula and the proximal end of the forearm.

Originate from 2 large fossae, 1 above and 1 below the spine, on the posterior surface of the scapula.

Supraspinatus initiates abduction of the arm. Infraspinatus laterally rotates the humerus.

Supraspinatus & Infraspinatus

A cord-like muscle

Laterally rotates the humerus

Component of the rotator cuff.

Teres minor

4 intrinsic shoulder muscles1) Supraspinatus2) Infraspinatus3) Teres minor4) Subscapularis

ROTATOR CUFF MUSCLES

(SITS muscles)

Form a musculotendinous rotator cuff around the glenohumeral joint.

ROTATOR CUFF MUSCLESFunctional exception:

All except supraspinatus are rotators of the humerus

Supraspinatus, besides being part of the rotator cuff, initiates and assists the deltoid in the first 15° of abduction of the arm.

The two major nerves of the posterior scapular region: Suprascapular & Axillary nerves

originate from the brachial plexus in the axilla.

Nerves

medial & lateral intermuscular septaAnterior compartment – flex the elbow jointPosterior compartment- extend the elbow joint

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ARM FlexionExtensionPronationSupination

Anterior compartment of the arm coracobrachialis, brachialis, and biceps brachii musclesinnervated predominantly by musculocutaneous nerve.

Posterior compartmenttriceps brachii muscle innervated by radial nerve.

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Deep artery of the arm (L. arteria profunda brachii)

Largest branch & most superior origin

Accompanies radial nerve along the radial groove

Terminates by dividing into middle & radial collateral arteries

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Brachial artery

2 main superficial veins of the armcephalic and basilic veins.

Cephalic vein – lateral sideinto axillary vein

Basilic vein- medial sideBasilic vein+ Brachial veins

Axillary vein

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4 main nerves pass through the arm: Median Ulnar Musculocutaneous Radial

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1. Which structures pass between the arm & forearm?

Most major structures (nerves,veins,arteries)via cubital fossa, anterior to elbow joint Exception ulnar nerveposterior to the medial epicondyle of humerus

2. How is forearm divided?

pronation

supination

3. Movements of the forearm muscles?

Muscles in the anterior compartment Flex the wrist & digits Pronate the handMuscles in the posterior compartment Extend the wrist & digitsSupinate the hand

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Muscles of the anterior compartment Mainly by median nerveThe one and a half exceptions by ulnar nerve Muscles of the posterior compartment All by radial nerve (directly or by its deep branch)

Watch out, Median nerve @median plane of the forearmUlnar nerve @ medial side

4. Innervation of the forearm muscles?

1. Layers of anterior compartment forearm muscles?Superficial Intermediate Deep

4 muscles 3 muscles

2. Muscles of the superficial layer?

1. flexor carpi radialis2. flexor carpi ulnaris3. palmaris longus4. pronator teres

two headsUlnar headHumeral head

Medial epicondyle

2. Muscles of the superficial layer?

1. flexor carpi radialis

Medial epicondyle of humerus Base of metacarpals II & III

2. flexor carpi ulnarisHumeral head: Medial epicondyle of humerusUlnar head: Olecranon & Posterior border of ulna•Pisiform & hamate •5th metacarpal3. palmaris longusMedial epicondyle of humerus Flexor retinaculum & palmar aponeurosis

4. pronator teresHumeral head: Medial epicondyle & adjacent supraepicondylar ridgeUlnar head: Coronoid processLateral surface of radius

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3. ..the muscles of the intermediate and deep layers?

flexor digitorum superficialis

3. Muscles of the intermediate layer?

Humeroulnar head• Medial epicondyle of humerus • Adjacent margin of coronoid processRadial headSuperior half of anterior border

Shafts of middle phalanges of

medial four digits

3. ..the muscles of the intermediate and deep layers?flexor digitorum profundus

flexor pollicis longus

pronator quadratus

4. Muscles of the deep layer?

•Proximal ¾ of medial & anterior surfaces of ulna

•Interosseous membrane

Bases of distal phalanges of 4th & 5th digitsBases of distal phalanges of 2nd & 3rd digits

• Anterior surface of radius• Adjacent interosseous

membrane

Base of distal phalanx of thumb

Distal ¼ of anterior surface of ulna

Distal ¼ of anterior surface of radius

5. Fxns of the anterior compartment muscles

Flexion of forearm @ the elbow jointPronator teresFlexion of hand @ the wrist jointFlexor carpi radialis et ulnaris- Palmaris longus

Abduction (radial deviation) of hand @ the wrist jointFlexor carpi radialis

Adduction (ulnar deviation) of hand @ the wrist jointFlexor carpi ulnaris

Pronation of forearmPronator teres – Pronator quadratus

5. Fxns of the anterior compartment muscles

Flexor digitorum superficialis

Flexor digitorum profundus Flexes distal phalanges 4 & 5 at distal interphalangeal joints

Flexes distal phalanges 2 and 3 at distal interphalangeal joints

Flexes proximal interphalangeal joints of the index, middle, ring, & little fingers Flexes metacarpophalangeal joints of the same fingers and the wrist joint

Flexor pollicis longusFlexes phalanges of thumb

6. Innervation of the anterior compartment muscles

All the muscles by median nerve

Except 1.5 muscles by ulnar nerveFlexor carpi ulnaris full

Flexor digitorum profundus medial half part associated w/ring & little fingers

7. Arteries in the anterior compartment of the forearm

Brachial artery

8. Veins in the anterior compartment of the forearm

deep venous palmar arch in

the hand

9. Median nerve

principal nerveno branches in the arm other than small twigs to the brachial artery. Its major branch in the forearm anterior interosseous nerve

Leaves cubital fossa by passing between 2 heads of pronator teres &humero-ulnar &radial heads of flexor digitorum superficialis

10. Ulnar nerve

Enters the anterior compartment by passing posteriorlyaround medial epicondyle of humerus &between humeral & ulnar heads of flexor carpi ulnaris muscle

Two small cutaneous branches palmar branch & dorsal branch

11. Radial nerve

motor and sensory functions in both arm & forearm but only sensory functions in the hand

Superficial (sensory)deep to brachioradialis

Deep (motor)between two heads of supinator

12. Lateral & medial cutaneous nerves of forearm

Lateral cutaneous nerve of forearmContinuation of musculocutaneous nerve

Medial cutaneous nerve of forearmBranch of medial cord of brachial plexus

Posterior cutaneous nerve of forearmBranch of radial nerve

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An important area of transition between the arm and the forearm. seen superficially as a depression on the anterior aspect of the elbow.

Deeply, it is a space filled with a variable amount of fat anterior to the most distal part of the humerus and the elbow joint.

1. What is the cubital fossa?

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Superiorly imaginary line connecting medial &lateral epicondyles.Medially pronator teres.Laterally brachioradialis.

2. What are the boundaries of the cubital fossa?

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1) Terminal part of the brachial artery,radial and ulnar arteries 2) Biceps brachii tendon

3) Median nerve

4) Radial nerve

5) (Deep) accompanying veins of the arteries

3. What are the contents of the cubital fossa?

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1. Which muscles are in the superficial layer?

Common origin lateral epicondyle of the humerus Except for the brachioradialis and anconeus, extend as tendons into the hand.

Brachioradialis

Extensor carpi radialis longusExtensor carpi radialis brevisExtensor carpi ulnarisExtensor digitorum

Extensor digiti minimi

Base of 2nd metacarpal

Base of 3rd metacarpalBase of 5th metacarpal

Anconeus

Proximal part of supraepicondylar ridge of humerus

Lateral surface of distal end of radius proximal to styloid process

Distal part of supraepicondylar ridge of humerus

Base of 2nd metacarpal

Lateral epicondyle of humerus common extensor origin

Base of 3rd metacarpals

Lateral epicondyle of humerus common extensor origin

Base of the 5th metacarpal

Lateral epicondyle of humerus

dorsal aspects of the bases of the middle and distal phalanges of the medial four digits

Lateral epicondyle of humerus

Extensor expansion (hood) of the 5th digit

Lateral epicondyle of humerus

Olecranon and proximal posterior surface of ulna

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2. Which muscles are in the deep layer?

Except for the supinator muscle, all these deep layer muscles originate from the posterior surfaces of the radius, ulna, and interosseous membrane and pass into the thumb and fingers.

Supinator

Abductor pollicis longus

Extensor pollicis brevisExtensor pollicis longus

Extensor indicis

Superficial (humeroulnar) head•lateral epicondyle of humerus•radial collateral and anular ligaments Deep (ulnar) head Supinator crest of the ulna

Lateral surface of radius superior to the anterior oblique line

Posterior surface of proximal halves of ulna, radius, and interosseous membrane

Base of 1st metacarpal

Posterior surface of middle third of ulna and interosseous membraneDorsal surface of base of distal phalanx of thumb

Posterior surface of distal third of radius and interosseous membraneDorsal surface of base of proximal phalanx of the thumb

Posterior surface of distal 1/3 of ulna and interosseous membrane

Extensor expansion (hood) of 2nd digit

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What is palmar aponeurosis?A triangular condensation of deep fascia that covers the palm and is anchored to the skin in distal regions.

Continuous with the palmaris longus tendon, when present; otherwise, anchored to the flexor retinaculum.

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functions the intrinsic muscles of the hand?

Palmar interosseiadduct the thumb, index, ring, and little fingers with respect to a long axis through the middle finger

Dorsal interosseimajor abductors of the index, middle, and ring fingers, at the metacarpophalangeal joints

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functions the intrinsic muscles of the hand?

Lumbricals

flexing metacarpophalangeal joints

extending interphalangeal joints

medial two deep branch of the ulnar nerve lateral two median nerve

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functions the intrinsic muscles of the hand?

Palmaris brevis

deepens cup of the palm by pulling on skin over the hypothenar eminence forming a distinct ridge.

This may improve grip.

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How are the intrinsic muscles innervated?All of the intrinsic muscles of the hand by deep branch of the ulnar nerve

Exceptthree thenar & two lateral lumbrical musclesby median nerve

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arteries of the hand?

Superficial palmar archDeep palmar arch

princeps pollicis artery

radialis indicis artery

• three palmar metacarpal arteries •three perforating branches

palmar digital artery

common palmar digital arteries

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Before penetrating the back of the hand, the radial artery gives rise to two vessels:

dorsal carpal branch passes medially as the dorsal carpal arch, across the wrist dorsal metacarpal arteriesdorsal digital arteries

first dorsal metacarpal artery supplies adjacent sides of the index finger and thumb.

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veins of the hand?Cephalic vein originates from lateral side of dorsal venous network. Basilic vein originates from medial side of dorsal venous network.

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sensory innervation of the hand?

Ulnar nerve medial side of the palm, medial half of the dorsum of the hand, 5th finger, medial half of the 4th finger, anterior surfaces of medial ½ digitsMedian nerve palmar surfaces of the lateral 3 ½ digits and cutaneous regions over the dorsal aspects of the distal phalanges (nail beds) of the same digitsRadial nerve dorsolateral aspect of the palm, dorsal aspects of the lateral three,one-half digits distally to approximately the terminal interphalangeal joints

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carpal tunnel?base of the carpal arch

formed medially by pisiform & hook of hamate

laterally by tubercles of scaphoid & trapezium

SLTP

TTCH