Inferior lateral brachial cutaneous nerve

At a glance

English

Inferior lateral brachial cutaneous nerve

Latin (TA2)

Nervus cutaneus lateralis inferior brachii

System

Nerve

Region

Upper limb

Side

Paired, left and right

About the inferior lateral brachial cutaneous nerve

The radial nerve winds round the back of the humerus in the radial groove, between the lateral and medial heads of triceps, together with the profunda brachii artery. Near the lower end of this groove it gives off the inferior lateral cutaneous nerve of the arm. The branch pierces the lateral head of triceps and the deep fascia on the lateral side of the arm, below the insertion of deltoid, and becomes superficial.

It supplies the skin of the lower lateral part of the arm, down to the region of the elbow. It often arises together with the posterior cutaneous nerve of the forearm, the radial branch that continues down the back of the forearm. Its territory meets that of the superior lateral cutaneous nerve of the arm, a branch of the axillary nerve, above, and that of the lateral cutaneous nerve of the forearm, from the musculocutaneous nerve, below.

The branch carries only sensory fibres. Because it leaves the radial nerve in or near the radial groove, the state of its skin area can help locate a radial nerve injury: a lesion high in the arm or in the axilla may numb this skin as well as the back of the hand, whereas an injury lower down may spare it. The nerve can be at risk in surgical approaches to the lateral side of the lower humerus.

Course and supply

Arises from

Radial nerve, in or near the lower part of the radial groove of the humerus.

Ends in

Skin of the lower lateral part of the arm, as far as the elbow.

Supplies

Sensory to the skin of the lower lateral arm; no motor fibres.