The humerus is the long bone in the upper arm, located between the elbow joint and the shoulder. At the elbow, it connects primarily to the ulna, as the forearm's radial bone connects to the wrist. At the shoulder, the humerus connects to the body through the scapula. The humerus bone is the home of many muscular insertion and origination points, including the deltoid, the pectoralis major, and many others. The brachial artery travels most of the bone's length, before it subdivides into the ulnar and radial arteries at the elbow. In the upper arm, the brachial branches into several arteries, transiting oxygenated blood from the lungs and heart. The radial nerve runs a similar course over the bone and into the forearm. Because it connects at the shoulder with a rotational joint, the humerus is instrumental in supporting many of the arm's functions, including all lifting and physical activities. Since the humerus is one of the longest bones in the body, it is one of the most commonly broken or fractured.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Humerus