Radial nerve Formation Largest branch of brachial plexus

Radial nerve

Formation • Largest branch of brachial plexus • Begins in axilla • Continuation of posterior cord • Dorsal branches of ventral rami of C 5, 6, 7, 8, T 1 • Nerve of extensor compartment of arm

Course and relation • Axilla • Triangular space • Spiral groove • Anterior compartment of lower arm • Front of lateral epicondyle divides into terminal branches Lateral intermuscular septum

Superficial terminal branch • Essentially sensory • Superficial to extensor brachioradialis retinaculum • Five dorsal digital branches

The deep terminal branch • Divides into 3 short and 2 long branches. • Long branch- abductor pollicis longus and extensor pollicis brevis, extensor pollicis longus and extensor indicis • Short branch-extensor digitorum, extensor digiti minimi, extensor carpi ulnaris • Ends as pseudo-ganglion at the back of wrist Extensor carpi radialis brevis

Branches- muscular, cutaneous, articular, vascular • • Branches in the axilla long head of triceps medial head of triceps posterior cutaneous nerve of the arm

Branches in the spiral groove -muscular br- lat and med head of triceps -posterior cutaneous nerve of the forearm -lower lateral cutaneous nerve of the arm Branches in the lower part of arm muscularbrachioradialis, extensor carpi radialis longus, lateral part of brachialis Lower lat cut nerve of arm post cut nerve of forearm

Lower lat cut nerve of arm Post cut nerve of forearm

Applied anatomy Inability to extend metacarpophalangeal jt. &thumb.