Anterior branch of medial antebrachial cutaneous nerve

At a glance

English

Anterior branch of medial antebrachial cutaneous nerve

Latin (TA2)

Ramus anterior nervi cutanei medialis antebrachii

System

Nerve

Region

Upper limb

Side

Paired, left and right

About the anterior branch of medial antebrachial cutaneous nerve

The medial cutaneous nerve of the forearm (medial antebrachial cutaneous nerve) is a purely sensory branch of the medial cord of the brachial plexus, with fibres from C8 and T1. It descends in the arm medial to the brachial artery, pierces the deep fascia with the basilic vein about halfway down the arm, and then divides into an anterior and a posterior branch. The anterior branch, also called the volar branch, is the larger of the two.

At the elbow the anterior branch runs close to the veins of the cubital fossa. It usually passes in front of the median cubital vein, though sometimes behind it. From there it travels down the front of the forearm on its ulnar (medial) side, in the superficial fascia, giving off fine twigs to the skin all the way to the wrist.

Its territory is the skin over the anterior and medial part of the forearm, from just above the elbow down to the wrist. At its lower end it connects with the ulnar nerve's palmar cutaneous branch, and its area overlaps with that of the lateral cutaneous nerve of the forearm in front and with the posterior branch of its own parent nerve behind. It carries no motor fibres.

Because it lies among the superficial veins at the elbow, the branch can be irritated or cut when blood is taken or a cannula is placed in the median cubital or basilic vein, producing tingling or numbness along the inner forearm. It is also at risk in surgery around the medial side of the elbow, for example when the ulnar nerve is moved forward. Surgeons sometimes harvest a segment of the medial cutaneous nerve of the forearm as a nerve graft, accepting a small patch of numbness on the forearm.

Course and supply

Arises from

One of the two terminal branches of the medial cutaneous nerve of the forearm, formed where the parent nerve divides in the lower arm (fibres C8, T1).

Ends in

Ends in cutaneous twigs at the wrist, communicating with the ulnar nerve's palmar cutaneous branch.

Supplies

Sensory to the skin of the anterior and medial forearm from the elbow to the wrist; no motor supply.