Question

• What are the roots of the brachial plexus?
• What are the major nerves (Terminal nerves) of the brachial plexus?
• What are the roots of the long thoracic nerve?
• Name 5 muscles that are innervated by the radial nerve
• Name 5 muscles that are innervated by the mdian nerve
• Name 5 muscles that are innervated by the ulnar nerve

Answer 1

1. Brachial plexus also known as plexus brachialis is a somatic nerve plexus. It is a network of nerve fibers that supplies the skin and the musculature of the upper limb. Brachial plexus originates from the lower cervical and the upper thoracic ventral nerve roots. It has 5 origins. They are : C5, C6, C7, C8, T1.

2. The 5 terminal branches of the brachial plexus are : musculocutaneous nerve, axillary nerve, median nerve, radial nerve and the ulnar nerve.

3. Long thoracic nerve is also known as external respiratory nerve of Bell or the posterior thoracic nerve. It originates from the proximal C5, C6 and C7 cervical nerves.

4. 5 muscles innervated by the radial nerve:

1. Brachioradialis
2. Extensor carpi radialis longus
3. Extensor carpi radialis brevis
4. Extensor digitorum
5. Extensor indicis

5. Five muscles innervated by median nerve :

1. Flexor carpi radialis
2. Palmaris longus
3. Pronator quadratus
4. Pronator teres
5. Digital flexor

6. Five muscles innervated by ulnar nerve:

1. Flexor carpi ulnaris
2. Flexor digitorum profundus
3. Dorsal interossei
4. Palmar interossei
5. Palmaris brevis