Add the dorsal carpal arch. The dorsal carpal branch of the radial artery anastomoses with the dorsal carpal branch of the ulnar artery and the anterior and posterior interosseous arteries to form the dorsal carpal arch. The branching from the radial artery is seen in the 3D cadaver, but because of it's caliber, the remaining arch is not visualized. It transversely crosses the distal carpals. From this arch arise three dorsal metacarpal arteries which pass distally over the second to fourth metacarpals before bifurcating into dorsal digital arteries to adjacent sides of the index, middle, ring and little fingers.
Add the ulnar artery.
Add the deep palmar arch. In the hand the radial artery passes between the heads of the first dorsal interosseous muscle and between the heads of adductor pollicis to terminate in the deep palmar arch through which it usually anastomoses with a deep branch of the ulnar artery. This usually complete arch runs transversely across the bases of the metacarpals in the palm deep to the long flexor tendons and lumbricals. Three palmar metacarpal arteries arise from the deep palmar arch and run distally on the interosseous muscles to anastomose with the common palmar digital arteries.
Add the superficial palmar arch. This arterial arch is superficial to all of the structures of the palm except the aponeurosis and palmaris brevis. It is the continuation of the ulnar artery beyond the flexor retinaculum and gives rise to four common palmar digital arteries. On the radial side it may anastomose with the superficial palmar branch of the radial artery (one third of cases) or the arteria princeps pollicis, arteria radialis indicis, or median artery (one third) to complete the arch. The remaining third of superficial palmar arches are derived from the ulnar artery alone.
