Appendicular Skeleton

Anatomy of the Wrist and Hand

The wrist is made of several bones called carpals, and the hand is made of metacarpals in the palm of the hand and phalanges in the fingers.

A carpal bone is one of a set of eight short bones that make up the wrist. These small bones resembling pebbles all connect together by ligaments. The ligaments that connect each bone make the bones highly flexible, which allows for a high range of motion in the wrist as the carpals glide past one another. The scaphoid and lunate carpal bones closely articulate with the radius. From lateral to medial, the most proximal row of carpals is made up of the scaphoid, lunate, triquetrum, and pisiform. The distal row is made up of the trapezium, trapezoid, capitate, and hamate carpals.

The distal carpals articulate with each metacarpal bone, which make up a set of five small long bones that form the palm of the hand. Each metacarpal has a distal base that articulates with the carpals, a shaft, and a head that articulates with the fingers. The head forms the knuckles when a fist is formed. Metacarpals are numbered from I to V starting from the lateral (thumb) side to the medial (pinky finger) side. The fingers extend from the metacarpals as a series of miniature long bones, each called a phalange bone. Collectively, these are also numbered from I to V. Phalange I (the thumb) contains two bones, the proximal phalange and distal phalange. Phalanges II–V are subdivided into proximal, middle, and distal phalanges. Proximally to distally, each phalange has a base that articulates with the head of the bone found proximally, a shaft, and a head.
The wrist is a set of eight small bones called carpals. Metacarpals are bones that make up the palm of the hand, and phalanges are bones that make up the fingers.