Deep palmar arch
The main function of the deep palmar arch is to provide blood supply for the bones, joints and deep muscles of the hand.
This article will discuss the anatomy and function of the deep palmar arch.
|Origin||Direct continuation of radial artery with a medial contribution from ulnar artery|
|Branches||Palmar metacarpal arteries, perforating branches, recurrent branches|
|Supply||Carpal bones, metacarpal bones, adjacent muscles of the hand, metacarpophalangeal and proximal interphalangeal joints, radioulnar joint|
Origin and course
The deep palmar arch is considered to be a direct palmar continuation of the radial artery. The arch arises between the two heads of the adductor pollicis muscle. It then courses medially, across the bases of the medial four metacarpal bones and adjacent interossei muscles.
Once it reaches the fifth metacarpal, it arches posteromedially to meet the deep branch of the ulnar artery. Occasionally, the deep palmar arch ends before connecting with the deep ulnar branch when it is referred to as an 'incomplete deep palmar arch'.
The deep palmar arch is located deep to the oblique head of adductor pollicis, the tendons of flexor digitorum longus, the flexor digitorum brevis and the lumbrical muscles. On its course, it is accompanied by the ulnar nerve. The deep palmar arch lies proximal to the superficial palmar arch with which it forms an anastomosis. To identify the location of the arches of the hand, hand surgeons use the imaginary line called Kaplan's cardinal line. This line extends from the apex of the interdigital fold between the abducted thumb and index finger toward the hook of hamate on the ulnar side of the hand, parallel with the middle crease of the hand.
Branches and supply
Along its course, the deep palmar arch gives off several types of branches that provide blood supply for the structures of the hand. These branches include:
- The palmar metacarpal arteries course distally across the second to fourth lumbricals, where each of them anastomoses with a corresponding common digital branch from the superficial palmar arch. These branches participate in the blood supply of the medial four metacarpal bones, metacarpophalangeal and proximal interphalangeal joints of the digits 2-4.
- The perforating branches arise from the concavity of the deep palmar arch and run in the interosseous spaces 2-4. They form anastomoses with the dorsal metacarpal arteries. Because of these anastomoses, the perforating branches are a significant connection between the dorsal carpal network and the deep arteries of the hand and remain important in the supply to the dorsum of the hand.
- The recurrent branches run proximally to supply the carpal bones, intercarpal joints and the radiocarpal joint. They terminate by anastomosing with the palmar carpal arch.
To learn more about the neurovasculature of the hand check out our other articles, videos, quizzes and labeled diagrams.