The term 'armbone' refers to the three bones that make up the human arm: the ULNA, the ulnar, and the humerus. The ULNA is the larger of the two forearm bones and is located on the medial side of the arm. The ulnar is the smaller of the two forearm bones and is located on the lateral side of the arm. The humerus is the bone in the upper arm that connects the shoulder to the elbow. All three bones work together to provide stability and movement to the arm.