II. Review of Major Branches of the Brachial
Plexus
The major terminal branches of the brachial plexus are the musculocutaneous,
median, axillary, radial, and ulnar nerves. You should be very familiar with
these nerves and the muscles they innervate. Remember to think of
compartments.
- Anterior compartment of the arm = musculocutaneous
(biceps, brachialis, coracobrachialis)
- Posterior compartment of the arm = radial nerve
(triceps)
- Anterior compartment of the forearm = median and ulnar nerves
(flexors and pronators)
- Posterior compartment of forearm = radial nerve
(extensors, supinators, and brachioradialis)
On the following pages there are charts and diagrams which summarize the
distribution of the major branches of the brachial plexus. Use them to
review.
Musculocutaneous and Median Nerves
Muscles innervated by Median
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
- Lateral half of flexor digitorum profundus
- Pronator quadratus
- Flexor pollicis longus
- Opponens pollicis
- First lumbrical
- Second lumbrical
Muscles innervated by Musculocutaneous
- Coracobrachialis
- Biceps Brachii
- Brachialis
Ulnar Nerve
Muscles innervated by the Ulnar
- Flexor carpi ulnaris
- medial half of flexor digitorum profundus
- Palmaris brevis
- Abductor digiti minimi
- Flexor digiti minimi
- Opponens digiti minimi
- Third and fourth lumbrical
- All the interossei muscles
Axillary and Radial Nerves
Muscles Innervated by Axillary Nerve
Muscles Innervated by Radial Nerve
- Triceps and Anconeus
- Brachialis
- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Supinator
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
- Extensor indicis
