Branches of Median Nerve
The median nerve gives off no branches in the arm (apart from an occasional vascular twig). Its branches arise in the cubital fossa, forearm, and hand.
Branches in the Cubital Fossa and Forearm
1. Muscular Branches
Given off in the cubital fossa to:
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
2. Anterior Interosseous Nerve
- Arises in the upper part of the forearm.
- Descends on the front of the interosseous membrane, accompanying the anterior interosseous artery, between flexor pollicis longus and flexor digitorum profundus.
- Passes deep to pronator quadratus and ends on the front of the carpus.
- Supplies:
- Flexor pollicis longus
- Lateral half of flexor digitorum profundus (tendons to index and middle fingers)
- Pronator quadratus
- Also gives articular branches to the distal radio-ulnar joint and wrist joint.
3. Palmar Cutaneous Branch
- Arises a short distance above the flexor retinaculum.
- Passes superficial to the flexor retinaculum (does not pass through the carpal tunnel).
- Supplies the skin over the thenar eminence and the central part of the palm.
- Clinically important: spared in carpal tunnel syndrome, so skin over the thenar eminence retains sensation.
4. Articular Branches
- To the elbow joint and the proximal radio-ulnar joint.
5. Vascular Branches
- Supply the radial and ulnar arteries.
6. Communicating Branch
- A communicating branch is given to the ulnar nerve in the forearm.
Terminal Branches
Immediately distal to the flexor retinaculum (in the palm), the median nerve divides into a lateral division and a medial division, which give rise to muscular and digital branches. (Detailed distribution covered separately under Median Nerve in the Hand and Carpal Tunnel.)
Summary — Muscles Supplied by Median Nerve (Mnemonic: LOAF + others)
| Region | Muscles |
|---|---|
| Forearm (direct branches) | Pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis |
| Forearm (via anterior interosseous nerve) | Flexor pollicis longus, lateral half of flexor digitorum profundus, pronator quadratus |
| Hand (via lateral division) | Lateral two Lumbricals (1st and 2nd), Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis |
“LOAF” — Lumbricals (1st & 2nd), Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis — the intrinsic hand muscles supplied by the median nerve.