Anterior Branch of Medial Antebrachial Cutaneous Nerve

Origin

The medial antebrachial cutaneous nerve arises from the medial cord of brachial plexus and divides into anterior and posterior terminal branches (C8—T1 spinal segments).

Course

The medial antebrachial cutaneous nerve is a large nerve that arises from the medial cord of the brachial plexus. It descends in the anterior compartment of the arm along with the ulnar nerve and medial to the axillary and brachial artery. The nerve then pierces the deep fascia at approximately the mid-arm, alongside the basilic vein to enter the subcutaneous tissues of the forearm. The medial antebrachial cutaneous nerve divides into anterior and posterior (or volar and ulnar) terminal branches.

The anterior branch (volar branch) of the medial antebrachial cutaneous nerve is typically larger than the posterior branch and usually passes anteriorly to the basilic vein. The nerve then descends on the anteromedial aspect of the forearm distributing small cutaneous branches to the ulnar side of the forearm as far as the wrist.

Branches

Distally the anterior branch communicates with the palmar cutaneous branch of the ulnar nerve. The nerve fibers from the anterior branch of medial antebrachial cutaneous nerve eventually end up relaying sensory information to the C8 and T1 segments of the cervical and thoracic spinal cord.

Supplied Structures

The anterior branch of the medial antebrachial cutaneous nerve provides cutaneous sensory innervation to the skin of the ulnar side of the forearm and wrist.