The musculocutaneous nerve is a mixed nerve that arises from the Brachial plexus. It contains fibers from spinal cord segments C5 to C7[^1].
Anatomy
The musculocutaneous nerve initially follows the inferior border of the pectoralis minor muscle, then pierces the coracobrachialis muscle and courses obliquely between the biceps brachii and brachialis muscles from the medial to the lateral aspect of the upper arm. Along its course, it gives off branches to both muscles, some of which continue to the joint capsule of the elbow joint. Above the elbow, the nerve pierces the superficial fascia lateral to the biceps tendon and enters the subcutaneous tissue of the forearm as the lateral antebrachial cutaneous nerve. There, at the level of the cubital fossa, it passes the cephalic vein and divides into a palmar and a dorsal branch.
Function
The musculocutaneous nerve provides motor innervation to the coracobrachialis, biceps brachii, and brachialis muscles. Sensory innervation is provided to the joint capsule of the elbow joint and the dorsal and palmar cutaneous areas on the radial aspect of the forearm.