Wrist bones. Coloured X-ray of the wrist bones in a healthy human hand. At centre are eight small carpal bones in the wrist. These articulate with the two long bones of the forearm (at bottom). Five metacarpal bones (upper centre) make up the palm of the hand. The thumb is at left. Each finger (not seen) is made up of phalanges bones which articulate with the metacarpals. This skeleton of bones enables the human hand to be used with great flexibility, helped especially by the joint between the wrist and the opposable thumb. It enables the wrist to be moved up and down, side to side, as well as to rotate in a circular motion.