Answer:
Ulna
Explanation:
The are two primary bones in the forearm: the radius and the ulna. The radius is on the lateral side of the forearm and the ulna on the medial side.
The ulna is a long bone that stretches from the elbow to the smallest finger, it narrows when it approaches the wrist.
The ulna forms part of the wrist joint and the elbow joint.
If the ulna is fractured, a cast that runs along the forearm is applied till the bone regrows together again.
