Musculocutaneous nerve

A critical nerve that plays a vital role in both motor and sensory functions of the upper limb.

The musculocutaneous nerve is a peripheral nerve derived from the brachial plexus, specifically arising from the lateral cord. It primarily innervates the muscles in the anterior compartment of the arm, including the biceps brachii, brachialis, and coracobrachialis, as well as providing sensory innervation to the skin of the lateral forearm.

Terminologia Anatomica

nervus musculocutaneus

System

Nervous system

Function

The primary function of the musculocutaneous nerve is to facilitate movement and sensation in the upper limb. It is particularly important for the flexion of the elbow joint, which is crucial for various daily activities such as lifting, pulling, and pushing. The biceps brachii, innervated by this nerve, also contributes to supination of the forearm. The sensory fibers of the musculocutaneous nerve provide critical information about touch, temperature, and pain from the lateral forearm. The dual motor and sensory roles of this nerve place it as a key player in the dynamic interaction between limb movement and sensory feedback, ensuring coordinated actions and a complete sensory experience.

Location

The musculocutaneous nerve is situated in the upper arm and can be traced from its origin at the lateral cord of the brachial plexus, where it typically emerges between the biceps brachii and coracobrachialis muscles. As it travels distally, it innervates the muscles in the anterior compartment of the arm, where it pierces through the coracobrachialis. Finally, the nerve continues its course into the forearm as the lateral antebrachial cutaneous nerve, supplying sensory innervation to the skin along the lateral side of the forearm.

Did You Know?

The musculocutaneous nerve can sometimes vary in its origin, occasionally also receiving contributions from the medial cord of the brachial plexus.
Injuries or lesions to the musculocutaneous nerve can lead to significant weakness and atrophy in the muscles it innervates, resulting in difficulty with elbow flexion.
The musculocutaneous nerve is one of the main nerves that is routinely monitored during surgeries involving the shoulder and upper arm to prevent complications.