Dorsal carpal branch of radial artery

The dorsal carpal branch (ramus carpeus dorsalis; posterior radial carpal artery) is a small vessel which arises beneath the Extensor tendons of the thumb; crossing the carpus transversely toward the medial border of the hand, it anastomoses with the dorsal carpal branch of the ulnar and with the volar and dorsal interosseous arteries to form a dorsal carpal network (dorsal carpal network). 

From this network are given off three slender dorsal metacarpal arteries, which run downward on the second, third, and fourth Interossei dorsales and bifurcate into the dorsal digital branches for the supply of the adjacent sides of the middle, ring, and little fingers respectively, communicating with the proper volar digital branches of the superficial volar arch.

Near their origins they anastomose with the deep volar arch by the superior perforating arteries, and near their points of bifurcation with the common volar digital vessels of the superficial volar arch by the inferior perforating arteries.