The ULNA is the longest bone in the human arm, measuring approximately one-third of the length of the arm from the elbow to the tip of the middle finger. It is located on the medial side of the forearm and runs parallel to the radius, the other long bone in the forearm. The ULNA is a long bone that connects the elbow joint to the wrist and hand. It is also responsible for providing stability to the elbow joint and allowing for the movement of the forearm and wrist.