What is the bony projection of the ulna at the elbow?

• A. Radius
• B. Olecranon
• C. Carpals
• D. Metacarpals

Answer: (B)

The olecranon is the prominent projection on the ulna at the elbow. It forms the point of the elbow and serves as the attachment site for the triceps muscle, helping straighten the arm. The olecranon (with the coronoid process) also contributes to the elbow joint's stability by forming part of the trochlear notch that articulates with the humerus, enabling smooth flexion and extension. You can palpate it as the large bump at the back of the elbow when the arm is extended.

Radius is the other forearm bone on the lateral side and does not create the elbow’s main projection. Carpals are the wrist bones, and metacarpals are in the hand—none of these form the elbow’s bony projection.