Corpus: Lateral antibrachial cutaneous nerve
from Latin: antebrachium - forearm; cutis - skin
Synonyms: lateral cutaneous nerve of the forearm, lateral cutaneous nerve of forearm
1. Definition
The lateral antibrachial cutaneous nerve is a sensory terminal branch of the musculocutaneous nerve. It carries fibers from the spinal cord segments C5 to C7.
2. Course
The nerve arises as an extension of the musculocutaneous nerve just above the elbow. There this nerve pierces the fascia lateral to the biceps tendon. It crosses the cephalic vein in the region of the cubital fossa and divides into a volar (Ramus volaris) and a dorsal branch (Ramus dorsalis) in the subcutaneous tissue.
The Ramus volaris descends along the volar radial side of the forearm to the wrist. Near the wrist, it is located above the radial artery and sends some fibers deep to the wrist along with it. Its fibers end in the skin of the thumb pad and communicate with superficial fibers from the radial and median nerves.
The Ramus dorsalis runs along the dorsal radial side of the forearm towards the wrist, but usually does not reach it.
3. Function
The lateral antibrachial cutaneous nerve (Nervus cutaneus antebrachii lateralis) provides sensory innervation to both the dorsal and volar skin areas on the radial side of the forearm. Volarly, its area of innervation is larger, extending to the thumb pad, while dorsally, it ends approximately at the level of the wrist.