The human arm is divided into two main sections: the forearm and the arm itself. The forearm is the section located between the elbow and the wrist, while the arm represents the section from the shoulder to the elbow. The main bone of the upper arm is the humerus. By contrast, the forearm consists of two main bones, the radius and the ulna.
The large bones of the arm include: Humerus: This bone runs down from the shoulder socket and joins the radius and ulna at the elbow. Radius: A forearm bone, it runs from the elbow to the thumb side of the wrist. Ulna: This forearm bone runs from the elbow to the “pinkie” side of the wrist. These three bones join to form the elbow.
The bones of the arm and hand have the important jobs of supporting the upper limb and providing attachment points for the muscles that move the upper limb.