Median nerve
Branches · C6 C7 C8 T1
Formed by a lateral and a medial root that straddle the axillary artery. Gives no branches in the arm, then supplies most of the flexor forearm and the thenar muscles.
Traced from the start
Detail
- Motor
- Most of the flexor compartment of the forearm, except flexor carpi ulnaris and the medial half of flexor digitorum profundus. The thenar muscles and the lateral two lumbricals — LOAF
- Sensory
- Palmar surface of the lateral three and a half digits, and the skin over the thenar eminence and lateral palm via the palmar cutaneous branch
When it goes wrong
Carpal tunnel syndrome
Night pain and numbness of the lateral three and a half digits with thenar wasting. Sensation over the thenar eminence and lateral palm is preserved, because the palmar cutaneous branch arises above the wrist and passes superficial to the flexor retinaculum.
Supracondylar fracture of the humerus in a child
Weak forearm pronation and thumb opposition, with the hand of benediction on attempting to make a fist.
Anterior interosseous nerve syndrome
A purely motor lesion — the OK sign cannot be made because flexor pollicis longus and the index part of flexor digitorum profundus are weak. There is no sensory loss.
Practise this structure
1 question in the bank tagged Median Nerve.