Deep palmar arch

At a glance

English

Deep palmar arch

Latin (TA2)

Arcus palmaris profundus

System

Artery

Region

Upper limb

Side

Paired, left and right

About the deep palmar arch

The deep palmar arch, sometimes called the deep volar arch, is a curved arterial channel across the palm of the hand. Most of it is the end of the radial artery, which reaches the palm by passing from the back of the hand between the two heads of the first dorsal interosseous muscle and then between the heads of adductor pollicis. The arch is completed on the medial side by the deep palmar branch of the ulnar artery. This is the reverse of the more superficial arch, built chiefly from the ulnar artery.

The arch lies very deep. It rests on the interosseous muscles and the proximal ends (bases) of the metacarpals, and above it lie the lumbricals, the long finger flexor tendons and the oblique head of adductor pollicis. The ulnar nerve's deep branch runs in the concavity of the arch but in the opposite direction, from the little-finger side towards the thumb.

Its position can be judged from surface landmarks. With the thumb fully extended, a line drawn across the palm from the lower border of the thumb marks the superficial arch, sometimes called Boeckel's line. The deep arch sits about one finger's breadth closer to the wrist.

From its convex distal side arise the palmar metacarpal arteries, which run towards the finger clefts and join the common palmar digital arteries of the superficial arch. Perforating branches pass backwards between the metacarpals to the dorsal metacarpal arteries, and small recurrent branches go up to the palmar carpal network. The radial artery also gives the main artery of the thumb and the radial artery of the index finger close to the start of the arch, so the deep system is the chief source of blood for the thumb and for the radial edge of the index finger. The links between the deep and superficial arches let blood reach the fingers from either forearm artery, and this is what the Allen test checks before the radial artery is punctured or harvested.

Course and supply

Arises from

The end of the radial artery, entering the palm between the heads of the first dorsal interosseous muscle.

Ends in

Completed medially by anastomosis with the deep palmar branch of the ulnar artery near the base of the fifth metacarpal.

Supplies

Supplies the deep structures of the palm and the interossei, and through its branches the thumb, the radial edge of the index finger and the intermetacarpal spaces; links with the superficial arch and the dorsal metacarpal arteries.