Which muscles are innervated by the musculocutaneous nerve?

The musculocutaneous nerve is a crucial nerve that primarily innervates specific muscles in the upper arm, particularly those involved in flexion at the elbow. The correct answer identifies three key muscles: the bicep brachii, coracobrachialis, and brachialis.

The bicep brachii is well-known for its role in flexing the elbow and supination of the forearm. The brachialis lies beneath the bicep brachii and is a primary flexor of the elbow joint, providing strong muscle support during elbow flexion. The coracobrachialis contributes to flexion and adduction of the shoulder joint, further establishing the musculocutaneous nerve's role in innervating muscles that facilitate movements of the upper arm and elbow.

This targeted innervation is a key characteristic of the musculocutaneous nerve, differentiating it from other nerves that serve the upper limb. Understanding this specific innervation is essential for recognizing how muscle movement and function in areas of the arm are coordinated, particularly in clinical assessments or rehabilitation contexts.