Arteries of Hand

Because its function requires it to be placed and held in many different positions, often while grasping or applying pressure, the hand is supplied with an abundance of highly branched and anastomosing arteries so that oxygenated blood is generally available to all parts in all positions. Furthermore, the arteries or their derivatives are relatively superficial, underlying skin that is capable of sweating so that excess heat can be released. To prevent undesirable heat loss in a cold environment, the arterioles of the hands are capable of reducing blood flow to the surface and to the ends of the fingers. The ulnar and radial arteries and their branches provide all the blood to the hand.

Ulnar Artery in Hand

The ulnar artery enters the hand anterior to the flexor retinaculum between the pisiform and the hook of the hamate via the ulnar canal (Guyon canal). The ulnar artery lies lateral to the ulnar nerve. The artery divides into two terminal branches, the superficial palmar arch and the deep palmar branch. The superficial palmar arch, the main termination of the ulnar artery, gives rise to three common palmar digital arteries that anastomose with the palmar metacarpal arteries from the deep palmar arch. Each common palmar digital artery divides into a pair of proper palmar digital arteries, which run along the adjacent sides of the 2^nd-4^th digits.

Radial Artery in Hand

The radial artery curves dorsally around the scaphoid and trapezium and crosses the floor of the anatomical snuff box. It enters the palm by passing between the heads of the 1^st dorsal interosseous muscle and then turns medially, passing between the heads of the adductor pollicis. The radial artery ends by anastomosing with the deep branch of the ulnar artery to form the deep palmar arch, which is formed mainly by the radial artery. This arch lies across the metacarpals just distal to their bases. The deep palmar arch gives rise to three palmar metacarpal arteries and the princeps pollicis artery. The radialis indicis artery passes along the lateral side of the index finger. It usually arises from the radial artery, but it may originate from the princeps pollicis.