The insertion of the triceps brachii is at which part of the ulna?

• A. Olecranon process of the ulna
• B. Coronoid process of the ulna
• C. Radial tuberosity
• D. Ulna head

Answer: (A)

The insertion point for the triceps brachii on the ulna is the olecranon process. This prominent bump at the back of the elbow is where the triceps tendon attaches, allowing the muscle to straighten the forearm when it contracts. The other ulna landmarks have different roles: the coronoid process is the attachment area for the brachialis and relates to elbow flexion and stability, the radial tuberosity is where the biceps brachii inserts (for forearm flexion and supination), and the ulna head is the distal end of the bone not involved in triceps insertion.