Hand anatomy. Illustration showing the bones, nerves and blood vessels of the hand.
The hand as we know it started to take shape when hominid species diverged from apes 5-7 million years ago. Today the human hand has 27 bones, made up of 14 phalanges on the fingers and thumb, five metacarpals connecting the fingers to the wrist, and eight carpal bones making up the base of the hand. The radial arteries (black) in the hand, drawn in black here, carry the blood around the hand from the forearm. The superficial palmar arch runs near the palm of the hand, whilst the deep palmar arch runs deeper in the hand. The hand is innervated by the median nerve (white) travelling to the thumb, forefinger and middle finger. The other two fingers on the left are served by the ulnar nerve (white).