What is the name of the bone in the upper arm?

The bone in the upper arm is the humerus. It extends from the shoulder to the elbow and connects the shoulder blade to the two bones of the forearm, the radius and ulna.

The humerus is a long bone with a rounded head that fits into the shoulder socket. Its lower end forms part of the elbow joint, meeting both the radius and ulna. Near the shoulder, the surgical neck is a frequent fracture site, especially after falls.

A common mix-up is confusing the humerus with the radius or ulna. The radius and ulna are forearm bones, while the femur is the corresponding long bone in the thigh. The humerus also provides attachment points for muscles that move the shoulder, elbow, and forearm.