Common palmar digital branches of median nerve

At a glance

English

Common palmar digital branches of median nerve

Latin (TA2)

Rami digitales palmares communes nervi mediani

System

Nerve

Region

Upper limb

Side

Paired, left and right

About the common palmar digital branches of median nerve

After passing through the carpal tunnel under the flexor retinaculum, the median nerve widens and flattens and soon divides into a smaller lateral part and a larger medial part. The common palmar digital nerves are the branches that run from these parts towards the webs between the fingers. In the palm they lie beneath the palmar aponeurosis and the superficial palmar arch, on the long flexor tendons and the lumbrical muscles.

The lateral part of the median nerve gives the recurrent (thenar) branch and a first common palmar digital nerve, which splits into proper digital nerves for both sides of the thumb and the radial side of the index finger; the branch to the index side usually supplies the first lumbrical. The medial part gives two more common palmar digital nerves. Of these, the first sends a twig to the second lumbrical and heads for the web between index and middle fingers. The second heads for the web between middle and ring fingers; an ulnar nerve twig joins it, and it may give a twig to the third lumbrical.

At each cleft the common nerve divides into two proper palmar digital nerves, one for each of the adjoining sides of the two fingers. These run along the fingers on the palmar side of the digital arteries and supply the skin of the palmar surface and also the backs of the end segments, including the nail beds.

Together the branches provide feeling over the palmar side of the thumb, index and middle fingers and the radial half of the ring finger, the part of the hand most used for fine touch and grip. They also supply the first and second lumbricals, which bend the knuckle joints while straightening the finger joints. Compression of the median nerve in the carpal tunnel produces numbness and tingling in exactly this territory, while the palm itself is spared because its skin is served by a branch that leaves the nerve above the wrist.

Course and supply

Arises from

Arise from the lateral and medial divisions of the median nerve in the palm, just distal to the flexor retinaculum.

Ends in

Each divides at a finger cleft into two proper palmar digital nerves serving neighbouring sides of the digits from the thumb to the ring finger.

Supplies

Sensory to the palmar skin of the lateral three and a half digits and the dorsal skin of their tips and nail beds; motor to the first and second lumbricals.