How many bones are there in the adult human arm, and what are their names?
Bones of the Arm The bones of the human arm extend from the shoulder to the wrist. The humerus is the bone of the upper arm. The rounded head of the humerus fits into a cavity in the scapula (shoulder blade) to form the shoulder joint. The shoulder joint is a ball-and-socket joint that enables full circular movement of the arm. The lower end of the humerus joins the bones of the forearm at the elbow to form a hinged joint. This hinged joint permits the forearm to bend up and down. The radius and ulna are two parallel bones that form the forearm. The radius is the shorter bone on the thumb-side of the forearm. The radius can rotate over the ulna, permitting the forearm to twist.
Bones of the Arm The bones of the human arm extend from the shoulder to the wrist. The humerus is the bone of the upper arm. The rounded head of the humerus fits into a cavity in the scapula (shoulder blade) to form the shoulder joint. The shoulder joint is a ball-and-socket joint that enables full circular movement of the arm. The lower end of the humerus joins the bones of the forearm at the elbow to form a hinged joint. This hinged joint permits the forearm to bend up and down. The radius and ulna are two parallel bones that form the forearm. The radius is the shorter bone on the thumb-side of the forearm. The radius can rotate over the ulna, permitting the forearm to twist. Sources: http://encarta.msn.com/encnet/refpages/RefMedia.aspx?
