Concepts
Non-clinical sciences/Anatomy · Upper-limb nerves

Median nerve

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What it means

Medial + lateral cords (C6–T1). Supplies most forearm flexors + the thenar LOAF muscles (Lateral two lumbricals, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis); sensation over the lateral 3½ digits (palmar). Compressed at the wrist = carpal tunnel syndrome; a high lesion gives the 'hand of benediction' on attempted fist.

Worked example

Nocturnal thumb/index/middle-finger paraesthesiae + thenar wasting + positive Tinel/Phalen = carpal tunnel (median nerve).

In the exam

A woman wakes with tingling of the thumb, index and middle fingers; over months the thenar eminence wastes and thumb abduction weakens.

What settles it

Median = thenar/LOAF + lateral palm. Ulnar = hypothenar/interossei + medial 1½ digits (clawing is WORSE with distal ulnar lesions — the 'ulnar paradox').

Classically confused with

Ulnar nerve

Source: TeachMeAnatomy — Median nerve