Anatomy - Upper Limb

Front 1

What nerve roots form the superior trunk of brachial plexus?

Back 1

C5, C6

Front 2

What nerve roots form the middle trunk of the brachial plexus?

Back 2

C7

Front 3

What nerve roots form the inferior trunk of the brachial plexus?

Back 3

C8, T1

Front 4

How is the axillary nerve formed?

Back 4

It's the superior branch of the posterior cord

Front 5

Muscles innervated by the axillary nerve

Back 5

Deltoid and teres minor

Front 6

Muscles innervated by the musculocutaneous nerve

Back 6

Biceps, brachial, choracobrachial

Front 7

Muscles innervated by the radial nerve

Back 7

Triceps and extensor muscles on the posterior compartments of arm and forearm

Front 8

Muscles innervated by the ulnar nerve

Back 8

Flexor carpi ulnaris, medial part of the flexor digitorus profundus, lumbricals 3 and 4, palmar interosseous, dorsal interosseous, adductor pollicis, abductor digiti minimi, flexor digiti minimi, opponens digiti minimi

Front 9

Muscles innervated by the median nerve

Back 9

Flexor muscles of the forearm except flexor carpi ulnaris and medial part of flexor digitorus profundus, lumbricals 1 and 2, abductor pollicis brevis, opponens pollicis brevis, flexor pollicis brevis.

Front 10

Actions of the axillary nerve

Back 10

Abduct shoulder (deltoid), lateral roation of the shoulder (teres minor)

Front 11

Actions of the musculocutaneous nerve

Back 11

Flexes elbow (biceps, chorachobrachial), supination (biceps brachii)

Front 12

Actions of the radial nerve

Back 12

Extends digits, wrist and elbow. Supination.

Front 13

Actions of the ulnar nerve

Back 13

Flexes wrist and digits 4 and 5. Abducts and adducts digits 2, 3, 4, 5.

Front 14

Actions of the median nerve

Back 14

Flexes wrist and digits, pronation; abduction, opposition and flexion of the thumb

Front 15

Clinical features of injury of the upper trunk of the brachial plexus

Back 15

C5, C6 are injured due to adduction traction of the arm and hyperextension of the neck (fall on shoulder or pull baby by the neck). Results in Erb-Duchene paralysis damaging axillary, musculocutaneous, suprascapular and phrenic nerves. Loss of shoulder and anterior arm muscles. Arm is medially rotated and adducted, forearm is extended and pronated (waiter's tip)

Front 16

Clinical features of injury of the lower trunk of the brachial plexus

Back 16

C8, T1 are injured by a sudden abduction upward pull of the arm (pull baby by the arm). Results in thoracic outlet syndrome damaging median and ulnar nerves as well as T1 sympathetics. Loss of muscles of forearm and hand and Horner's syndrome (ptosis, miosis, anhydrosis)

Front 17

Long thoracic nerve injury

Back 17

Paralysis of the serratus anterior. No abduction of the arm past the horizontal position. Can't push (winging of the scapula)

Front 18

Axillary nerve injury

Back 18

Injured by fracture at the surgical neck of humerus or anterior dislocation of the shoulder. Cant abduct the shoulder to the horizontal plane, cant lateral rotate shoulder (teres minor). Sensory loss at the shoulder.

Front 19

Radial nerve injury at the axilla

Back 19

Shoulder dislocation or pressure on the floor of the axilla. No extension of the elbow, wrist or digits. Weak supination. Sensory loss of posterior arm, posterior forearm and posterolateral hand. "Wrist drop"

Front 20

Radial nerve injury at the arm

Back 20

Midshaft fracture of the humerus. No extension of the wrist or digits. Sensory loss on the posterior forearm and posterolateral hand. "Wrist drop"

Front 21

Radial nerve injury at the wrist

Back 21

Sensory loss on the lateral part of the dorsum of the hand.

Front 22

Median nerve injury at the elbow

Back 22

Supracondylar fracture of the humerus. Weak flexion of the wrist with ulnar deviation upon flexion. No flexion of digits 1 and 2, thenar muscles and lumbricals 1 and 2. Sensory loss on lateral palm and fingers 1, 2 and 3. Flattening of the thenar eminence (ape hand) and index and middle fingers cant make a fist.

Front 23

Median nerve injury at the wrist

Back 23

Slashing of the wrist (suicide attempt). Loss of thenar muscles and lumbricals 1 and 2. Sensory loss on lateral palm and fingers 1, 2 and 3. Flattening of the thenar eminence (ape hand) and index and middle fingers cant make a fist.

Front 24

Ulnar nerve injury at the elbow

Back 24

Fracture of the medial epicondyle of the humerus. Hand deviates radially when flexed (injured flexor carpis ulnaris), no flexion of ring and little fingers (injured flexor digitorus profundus and lumbricals 3, 4), abduction and adduction of the fingers is lost (injured palmar and dorsal interosseous), no adduction of the thumb, no mevement of little finger. Sensory lost on lateral half of ring finger and little finger. "Claw hand".

Front 25

Ulnar nerve injury at the wrist

Back 25

Slashing of the wrist (suicide attempt). Loss of abduction and adduction of the digits, loss of hypothenar muscles and lumbricals 3, 4. Sensory loss on lateral half of digit 4 and 5. "Claw hand".

Front 26

Musculocutaneous nerve injury

Back 26

Loss of elbow flexion and weak suppination. Loss of sensation on lateral aspect of the forearm.

Front 27

Branches of the brachiocephalic trunk

Back 27

Left subclavian and left common carotid arteries

Front 28

Branches of the subclavian artery

Back 28

Internal thoracic artery (continuous with superior epigastric and inferior epigastric which provide colateral circulation in postductal coarctation of the aorta), vertebral artery.

Front 29

Branches of the axillary artery

Back 29

Thoracoacromial, lateral thoracic (mammary gland), subscapular (collateral to shoulder), posterior and anterior humeral circumflex arteries.

Front 30

Branches of the brachial artery

Back 30

Deep brachial artery (together with radial nerve at midshaft of humerus), ulnar artery and radial artery at the cubital fossa.

Front 31

Branches of the ulnar artery

Back 31

Common interosseous artery and superficial palmar arch

Front 32

Branches of the radial artery

Back 32

Deep palmar arch

Front 33

Rotator cuff muscles

Back 33

Subscapularis, Infraspinatous, Teres minor, Supraspinatous. "SITS"

Front 34

What are the joints of the elbow and what is the function of each?

Back 34

Humeroulnar and humeroradial permit flexion and extension. The radioulnar permits pronation and supination.

Front 35

Wrist and hand joints

Back 35

Radiocarpal joint (between the distal radius and scaphoid/lunate carpal bones), ulnocarpal joint, midcarpal joint (between proximal and distal carpal bones), carpometacarpal joints.

Front 36

What are the carpal bones

Back 36

From lateral to medial. Proximal row: scaphoid, lunate, triquetrum, pisiform. Distal row: trapezium, trapezoid, capitate, hamate.

Front 37

What are the structures in the carpal tunnel?

Back 37

Flexor digitorum superficialis (4 tendons), flexor digitalis profundus (4 tendons), flexor pollicis longus and median nerve.

Front 38

Fracture of the scaphoid bone

Back 38

Results in avascular necrosis of the proximal head of the scaphoid.

Front 39

Lunate bone dislocation

Back 39

Results in median nerve compression in the carpal tunnel