nerves - r, m, u Flashcards
motor supply of median nerve in forearm
supply the anterior forearm (except flexor carpi ulnaris which is supply by ulnar n)
- directly ->
superficial layer:
- pronator teres: attached at both medial epicondyle + coronoid process of ulna -> lateral to mid shaft of radius; action = pronation of forearm
- flexor carpi radialis: attached from medial epicondyle to base of metacarpals II and III -> flex and abduction at wrist
- palmaris longus: (absent in 15%), originate from medial epicondyle to flexor retinaculum of wrist -> flex wrist
immediate layer:
- flexor digitorm superficialis (median and ulnar artery pass between its two heads -> travel posteriorly)
2 heads from medial epicondyle of humerus and radius -> 4 tendons at wrist into carpal tunnel to middle phalanges of 4 ingers
what are the autonomous sensory areas of the hand (only 1 nerves always supplies this area) for m, r, and u nerve
median n - distal phalanges of index and middle finger
ulnar n - middle and distal phalanges of little finger
radial n - over first dorsal interosseus muscle between first and second metacarpals
what are the autonomous motor supply of the hand for m, u and r nerve?
median nerve - abductor pollicis brevis (lift thumb to ceiling against resistance and feeling the thenar eminence for the power of the muscle)
ulnar nerve - palmar interossei (adduction of the fingers)
radial nerve - metacarpophalangeal extensor (extension of teh fingers at the knuckles)
describe the course of the median n.
from medial and lateral cords of brachial plexus in axilla -> descend down arm lateral to brachial artery -> 1/2 way cross over brachial a. become medially -> anterior compartment to forearm via cubital fossa->
forearm: between flexor digitorum profundus and flexor digitorum superficials muscles -> 2 major branch (anterior interosseous n -> deep muscle of forearm & palmar cutaneous n. -> innervates skin of lateral palm ->
hand (enter via carpal tunnel -> terminates as recurrent branch -> supply thenar muscls
