Download POSTERIOR ANTEBRACHIUM

POSTERIOR
ANTEBRACHIUM
Extensor Retinaculum

Deep fascia

Transversely crosses distal ends of radius
and ulna.
Extensor Retinaculum

Converts grooves in radius into tunnels for
extensor tendons (lateral to medial):
Abductor pollicis longus
Extensor pollicis brevis
Styloid process
Extensor carpi radialis longus
Extensor carpi radialis brevis
Dorsal tubercle
Extensor pollicis longus
Extensor digitorum and extensor indicis
Radial Nerve
Pierces lateral intermuscular septum in
lower arm and enters antebrachium
between brachioradialis and brachialis
muscles.
 Passes in front of lateral epicondyle and
enters cubital fossa.
 Divides into superficial and deep
branches.

Radial Nerve Deep Branch
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Wraps laterally around radius between
superficial and deep layers of supinator.
= posterior interosseous nerve.
Runs with posterior interosseous artery.
Motor to all extensor muscles of the forearm
except extensor carpi radialis longus and
anconeus.
Radial Nerve Superficial Branch

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Cutaneous.
Accompanies radial artery proximally.
Emerges from beneath brachioradialis in distal
forearm.
Supplies lateral half of dorsum of hand and
dorsum of thumb and index finger.
Radial Artery
Smallest terminal branch of brachial artery.
 Proximally lies deep to brachioradialis.
 Distally becomes superficial between
brachioradialis and flexor carpi radialis.
 Winds dorsally through anatomical snuffbox.

Radial Artery Branches
Radial recurrent
 Dorsal carpal artery
 Dorsal metacarpal and digital arteries
 First dorsal metacarpal:

Princeps pollicis
Radialis indicis
Interosseous Arteries
From common interosseous artery from
ulnar artery.
 One on either side of interosseous
membrane.

Superficial Muscles
Primarily wrist and hand extensors
 Common origin = lateral epicondyle:

Superior to inferior:
Brachioradialis
Extensor carpi radialis longus
Extensor radialis brevis
Extensor digitorum (communis)
Extensor digiti minimi
Extensor carpi ulnaris
Deep Muscles

Four muscles emerge from antebrachium
between extensor carpi radialis muscles
and the extensor digitorum muscle.
Three outcropping muscles insert on thumb:
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indicis.

Supinator