Dorsum of the Hand Anatomy
The dorsum of the hand is
innervated by branches of the radial and ulnar nerves (Fig.
3.78). The superficial branch of the radial nerve usually supplies the skin
of the lateral three and one-half digits (excluding the nail beds) and a
corresponding part of the dorsum of the hand. Skin of the dorsal aspect of the
first web space is usually supplied exclusively by the radial nerve and is
tested when radial nerve injury is suspected. The skin over the remainder of
the posterior aspect of the hand and the medial one and one-half fingers (excluding the nail beds) is
supplied by dorsal branches of the ulnar nerve that arise in the anterior
compartment and pass around the medial aspect of the wrist.
Much of the venous blood from the
digits and the palm drains into a network of vessels that often forms a
superficial venous arch on the dorsum of the hand.
At the wrist, the tendons of
extensor digitorum lie deep to the extensor retinaculum (Fig.
3.79), invested by a single synovial sheath. On the dorsum of the hand, the
tendons diverge to reach the fingers.
Skin on the dorsum of the hand is
elastic and freely mobile on the underlying loose connective tissue: infection
or injury of the hand frequently results in swelling (oedema) of these lax
tissues.
