Handshake. Coloured X-ray of a handshake. This may depict friendship, a greeting, bonding, or networking. Apart from the bones in each hand and arm, an outline of the flesh is seen. The forearm bones are the radius (upper left & right) and ulna. The hand consists of eight small wrist bones (carpals), five palm bones (metacarpals), and each finger has three phalanges, except the thumb which has two such bones. This skeleton enables the human hand to be used with great flexibility, helped especially by the joint between the wrist and the opposable thumb. Also seen is a wristwatch (centre left).