Elbow Bones and Joints
The three bones that make up the elbow joint are the humerus (upper arm,) and the two bones of the forearm, the radius and ulna. With your palm facing forward the radius is the bone that is most lateral and the ulna is the bone closest to your body.
The prominent part of the elbow on the posterior side (the pointed part) is called the olecranon, and is part of the ulna bone. On the inside and outside of the elbow lie the medial and lateral epicondyles. They are part of the distal humerus.
The three joints of the elbow are the ulnahumeral joint, the radiohumeral joint and the superior radioulnar joint. The superior radioulnar joint works with the inferior radioulnar joint of the wrist to turn our palm up and down. The osseous joint has articular cartilage, which covers the ends of the bones. The articular cartilage has a smooth and shiny surface that allows the ends of the bones to slide freely over each other.