what forms the elbow
Half of the elbow is formed by the humerus, the lone bone of the arm. The forearm contains two bones; the radius is on the lateral side of the forearm and the ulna is on the medial side. The humerus: The head of the humerus forms the glenohumeral joint of the shoulder with the scapula. The distal end of the humerus (at the elbow) has two prominent bumps: the medial and lateral epicondyles. Medial and lateral supraepicondylar ridges follow the shaft of the humerus down to the epicondyles.