Cross Sections of Upper Limb

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Cross Sectional Anatomy:Upper Limb

___________________________________________________________________________________Section 1:

a. cephalic veinb. deltoidc. humerusd. lateral head of triceps brachiie. long head of triceps brachiif. medial head of triceps brachiig. basilic veinh. coracobrachialisi. musculocutaneous nerve

j. biceps brachii

Section 2:a. brachialisb. radial nervec. brachial arteryd. ulnar nervee. median nerve

Section 3:a. brachioradialisb. radial nervec. lateral supracondylar ridged. ulnar nervee. median nerve

Section 4:a. extensor carpi radialis longusb. extensor carpi radialis brevisc. capitulumd. anconeuse. olecranon process of ulna


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d. extensor carpi radialis brevise. extensor digitorumf. supinatorg. extensor digiti minimih. extensor carpi ulnaris

i. anconeusj. flexor digitorum profundusk. flexor carpi ulnarisl. ulnar nervem. common interosseous arteryn. flexor digitorum superficialiso. median nervep. flexor carpi radialisq. pronator teres

Section 7:a. brachioradialisb. extensor carpi radialis longus tendonc. extensor carpi radialis brevis muscle and tendond. deep branch of radial nervee. extensor digitorumf. abductor pollicis longusg. extensor digiti minimi

h. extensor pollicis longusi. extensor carpi ulnaris

j. flexor digitorum profundusk. flexor carpi ulnarisl. ulnar nervem. interosseous membranen. palmaris longus tendono. flexor digitorum superficialisp. median nerveq. flexor pollicis longus

Section 8:a. flexor carpi radialis


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e. lunatef. extensor tendons of posterior forearmg. triquetrumh. hypothenar compartment musclesi. flexor tendons of anterior forearm

j. capitatek. thenar compartment muscles

Section 10:a. abductor digiti minimib. tendons of flexor digitorum superficialis and profundusc. palmar aponeurosis and digital branch of median nerved. tendon of flexor pollicis longus and radial bursae. flexor pollicis brevis

f. abductor pollicis brevisg. tendon of extensor pollicis longus and first metacarpalh. princeps pollicis arteryi. first dorsal interosseous

j. adductor pollicisk. lumbrical and tendon of flexor digitorum profundusl. tendons of extensor digitorumm. tendons of extensor digitorumn. third palmar interosseous and fifth metacarpal

Section 11:a. tendons of flexor digitorum superficialis and profundusb. third and fourth lumbricalsc. common palmar digital arteryd. tendon of flexor digitorum superficialise. tendon of flexor digitorum profundusf. second dorsal interosseous and first palmar interosseousg. second palmar interosseous muscle

Section 12:a. proper palmar digital nerve and artery.b. tendon of flexor digitorum profundus


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Descends anterior to axillary artery, enters radial groove of humerus w/ deep (profunda) brachialartery. Passes between lateral & medial head of triceps.

Passes into cubital fossa by piercing lateral intermuscular septum to lie between the brachialisand brachioradialis muscles.

At lateral epicondyle, it divides into a SUPERFICIAL and DEEP BRANCHES.

The SUPERFICIAL BRANCH accompanies the radial artery and both run under the brachioradialisto supply sensory innvervation to the dorsum of the hand.

- Superficial radial nerve courses through the Snuff Box- Supplies skin of the posterior surface of the thumb, index, and half of middle finger.

(except the distal phalanges of these digits which are supplied by the median nerve.)

The DEEP BRANCH passes between the 2 heads of the Supinator muscle and comes to liebetween superficial and deep extensors; After the deep branch exits from between the twoheads of the supinator muscles, it is called the POSTERIOR INTEROSSEOUS NERVE andaccompanies the Posterior interosseous artery.

-POSTERIOR INTEROSSEOUS NERVE innervates many of the posterior compartment ofthe forearm distal to the supinator.

UlnarFrom medial cord (C8,T1 often C7)

Passes down medial aspect of arm (pierces IM septum to lie in post compartment).Entersforearm by passing behind medial epicondyle. Goes between the two heads of the flexor carpiulnaris which it innervates. Runs between flexor carpi ulnaris and flexor digitorum profundus

(innv only medial of FDP). Ulnar nerves lies superficially in distal part of forearm:

Courses lateral to pisiform and anterior to carpal tunnel.

Divides into SUPERFICIAL and DEEP BRANCH in the hand. A DORSAL BRANCH of the ulnar nervebranches off in the lower third of the forearm.

SUPERFICIAL BRANCH innervates/supplies:

Palmaris brevis

Divides into digital nerves which are sensory to the palmar surface and sidesof the little finger and medial half of ring finger

DEEP BRANCH supplies:

All three muscles of hypothenar compartment: palmaris brevis, abductor digitiminimi, flexor digiti minimi and opponens digiti minimi

3rd and 4th lumbricals


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Before the tunnel, it gives offPALMAR CUTANEOUS BRANCH that runs anterior to flexorretinaculum and supplies skin of thenar area. At the distal border of the flexor retinaculum, itdivides into branches that are Motor and Sensory.

After passing through carpal tunnel it gives offMOTOR (RECURRENT) BRANCHBRANCH . It is motor to the 3 thenar muscles and the first and second lumbricals.

Innvervates: abductor pollicis brevis,

opponens pollicis,

superficial head of flexor pollicis brevis LATERAL BRANCH (SENSORY)

Innvervates:

Lateral palmar surface

Palmar surface of digits 1-3

Lateral half of digit 4 (via palmar and proper digital nerves). Thesenerves are also sensory to the dorsum of the distal halves of digits 2-4.

Note: The motor (recurrent) branch to the thenar muscles arises at the distalborder of the flexor retinaculum and is superficial in position. It is vunerable tocuts on thenar eminence.

Dorsal Scapular

From ventral ramus C5/ w freq contribution from C4

Pierces scalenus medius and descends deep to Levator scapulae and enters deep surface ofrhomboids.

Long Thoracic

From ventral rami of C5,C6, C7

Descends posteriorly to C8 + T1 rami and passes distally on external surface of serratus anterior.

Nerve To Subclavius From superior trunk (C5,C6, often C4)

Descends posterior to clavicle & anterior to brachial plexus & subclavius

Innv: subclavius, sternoclavicular joint


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Innv. Skin on medial side of arm

Medial Antebrachial Cutaneous

From medial cord (C8,T1)

Runs between axillary A + Vein, then on medial side of brachial artery.

Pierces deep fascia in cubital fossa and runs along medial aspect of forearm Innv: skin over medial side of forearm

Upper Subscapular

From posterior cord (C6-C8)

Arises between upper + lower subscapular nerves & runs inferolaterally along posterior axillarywall to latissimus dorsi

Thoracodorsal

From posterior cord (C6-C8)

Arises btw upper + lower subscapular nerves + runs inferolaterally along posterior axillary wall tolatissimus dorsi

Lower subscapular

From posterior cord (C5,C6)

Passes inferolaterally, deep to subscapular artery + vein to innv. Subscapularis and Teres major

ABDUCTORS OF WRIST/HAND

Flexor carpi radialis

Extensor carpi radialis longus

Extensor carpi radialis brevis

Extensor pollicis brevis

Extensor pollicis longus

ADDUCTORS OF WRIST/HAND

Flexor carpi ulnaris

Extensor carpi ulnaris

ABDUCTORS OF ARM Deltoid

Supraspinatus

ADDUCTORS OF ARM Deltoid

Teres Major

Corocobrachialis


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- results from injury to the upper trunk (C5,6) of the brachial plexus which may occur during thecourse of a complicated birth. In such a delivery, marked downward traction on the head of the fetusresults in a widening of the angle between the head and shoulder. In this paralysis, the hand hangs atthe side in medial rotation with the forearm pronated and the fingers and wrist relaxed. This isreferred to as the "head waiter's tip hand". The clinical appearance is produced by a paralysis of the

abductors and lateral rotators of the shoulder joint which are innervated by the axillary (deltoid, teresminor) and suprascapular (supraspinatus and infraspinatus) nerves (C5,6).AbductorsDeltoidSupraspinatusLateral rotators

Teres minorInfraspinatus

-There is also a weakness of the flexors of the elbow. Since the biceps is a powerful supinator, this

weakness will also result in pronation of the hand.Biceps through musculocutaneous (C5,6,7)Brachialis through musculocutaneous (C5,6,7)Brachioradialis through radial (C5,6,7,8, and T1)

- There is a weakness of the adductors and medial rotators of the shoulder:Pectoralis major through lateral pectoral nerve (C5,6,7)Latissimus dorsi through thoracodorsal nerve (C5,6,7)

2. Posterior Cord

- poor fitting crutches = pressure on radial n.- saturday night palsy = intoxicated person hangs arm over back of chair for extended time-- Wrist Drop* person unable to extend forarm, hand, digits due to affected muscles inner. by radial

n.

3. Lower Brachial Plexus- sudden upward pulling of upper limb (break a fall, babies limb pulled excessively)- cervical rib or pulmonary carcinoma

- inferior trunk of brachial plexus > Ulnar n. (C8, T1)- see Claw Hand exp.- KLUMPKE PARALYSIS. This results from injury to the lower trunk of the brachial plexus and mayresult from upward traction on the shoulder. It may be sustained in falling from a high place and


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- wrist drop not as severe- ECR Longus and Brevis are spared- still loss of digital extension of prox. phalages and thumb

8. Median N. - injury in axilla- loss of forearm pronation, diminished hand and digital flexion

- wasting of thenar eminence- loss of palmar senation and loss of sweating on lateral palm9. Median N. - injury at wrist / Carpal Tunnel Syn.

- wasting away of thenar eminence- loss of sensation

10. Ulnar N. - injury in axilla, arm or medial epicond. fracture- severe motor and sensory loss to the hand- Claw Hand

* imbalance of flex / ext. which occurs at MP and IP joints

* unable to aBduct or aDduct digits 2-5 (loss to interossei)* hyperextended MP joints of digits 4 & 5 and somewhat flexed IP joints (loss of

lumbricals 4-5)* will not be able to make a fist = b/c FDP to digit 4-5 is affected


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Documents

Cross Sections of Upper Limb