The ulna is one of the two long bones in the forearm, the other being the radius. It is located on the inner side of the forearm, opposite the thumb. The ulna is slightly longer than the radius and plays a crucial role in forming the elbow joint with the humerus and the wrist joint with the carpals. The ulna has a distinctive shape, featuring a prominent bony projection called the olecranon at its upper end, which forms the point of the elbow. This bone helps in the movement of the arm and provides stability during various activities, such as lifting and pushing.