Musculocutaneous Nerve

Question 1

What are the nerve roots for the Musculocutaneous nerve?

Answer 1

C5, C6, C7.

Question 2

What are the motor functions of the Musculocutaneous nerve?

Answer 2

Innervates the brachialis, biceps brachii and coracobrachialis muscles.

Question 3

What are the sensory functions of the Musculocutaneous nerve?

Answer 3

Gives off the lateral cutaneous branch of the forearm, which innervates the lateral half of the anterior forearm, and a small lateral portion of the posterior forearm.

Question 4

Describe the anatomical course of the Musculocutaneous nerve

Answer 4

• arises from the lateral cord of the brachial plexus (and therefore contains fibres from spinal roots C5, C6 and C7)
• the musculocutaneous nerve leaves the axilla, and pierces the coracobrachialis muscle, near its point of insertion on the humerus.
• it then passes down the arm, anterior to the brachialis muscle but deep to the biceps brachii, innervating them both.
• emerges laterally to the biceps tendon, and continues into the forearm as the lateral cutaneous nerve. It provides sensory innervation to the lateral aspect of the forearm