Bones of the Arm and Hand (Posterior View)

The scapula, or shoulder blade, serves as an attachment for some of the muscles and tendons of the arm, neck, chest and back and aids in the movements of the arm and shoulder. In the shallow socket of the scapula, at the shoulder joint, lies the humerus, which is also known as the upper arm bone. It joins with the bones of the lower arm (the ulna and radius) to make up the elbow. The ulna is the longer of the two bones in the forearm (the other is the radius). While the upper end of the ulna meets up with the lower end of the humerus at the elbow joint, the lower end of the ulna forms a joint with the wrist bones and lower end of the radius. The radius is the bone on the thumb side of the arm.

The skeleton of the wrist consists of eight small carpal bones. The metacarpal bones are five, long cylindrical bones in the body of the hand. They run from the bones of the wrist to the base of each digit of the hand. These bones connect to the phalanges, which are fourteen small bones that make up the skeleton of the fingers and thumb. Each finger has three phalanges; the thumb has two. The skeletal system of the upper extremities supports the muscles and tendons that allow movement in the shoulder, arm, wrist and hands.