The superficial palmar arch is formed predominantly by the ulnar artery, with a contribution from the superficial palmar branch of the radial artery. However, in some individuals the contribution from the radial artery might be absent, and instead anastomoses with either the princeps pollicis ar tery, the radialis indicis artery, or the median artery, the former two of which are branches from the radial artery. Alternative names for this arterial arch are: superficial volar arch [1] , superficial ulnar arch, arcus palmaris superficialis [2] , or arcus volaris superficial is. [3] The arch passes across the palm in a curve with its convexity downward. If one were to fully extend the thumb, the superficial palmar arch would lie approximately at the level ofa line drawn from the distal border of the thumb across the palm. The superficial palmar arch is more distal than the deep palmar arch. Three common palmar digital arteries arise from the arch, proceeding down on the second, third, and fourth lumbrical muscles, respectively. They each receive a contribution from a palmar metacarpal artery. Near the level of the metacarpophalangeal joints, each common palmar digital artery divides into two proper palmar digital arteries. The deep palmar arch (deep volar arch) is an arterial network found in the palm. It is usually formed mainly from the terminal part of the radial artery, with the ulnar artery contributing via its deep palmar branch. This is in contrast to the superficial palmar arch, which is formed predominantly by the ulnar artery. The deep palmar arch lies upon the bases of the metacarpal bones and on the interossei of the hand, being covered by the oblique head of the adductor pollicis muscle, the flexor tendons of the fingers, and the lumbricals of the hand. Alongside of it, but running in the opposite directionthat is to say, toward the radial side of the handis the deep branch of the ulnar nerve. The superficial palmar arch is more distally located than the deep palmar arch. If one were to fully extend the thumb and draw a line from the distal border of the thumb across the palm, this would be the level of the superficial palmar arch. The deep palmar arch is about a finger width proximal to this. From the deep palmar arch emerge palmar metacarpal arteries. The palmar metacarpal arteries (volar metacarpal arteries, palmar interosseous arteries), three or four in number, arise from the convexity of the deep volar arch They run distally upon the Interossei, and anastomose at the clefts of the fingers with the common digital branches of the superficial volar arch.
