Which bone is the longer of the two bones in the forearm that extends from the elbow to the wrist?

• A. Radius
• B. Ulna
• C. Humerus
• D. Fibula

Answer: (B)

In the forearm, two long bones run from the elbow to the wrist: the ulna and the radius. The longer of the two is the ulna, which sits on the medial side of the forearm (toward the little finger). It provides most of the structural length, with the elbow end forming the olecranon and the distal end near the wrist. The radius is shorter and lies on the lateral side (toward the thumb); it crosses over the ulna during forearm rotation to allow turning the hand. The humerus is the upper arm bone, and the fibula is a leg bone, so they don’t fit the description. Therefore, the longer forearm bone extending from elbow to wrist is the ulna.