What bony landmark accommodates the olecranon process during elbow extension?

The olecranon fossa is a crucial bony landmark located at the distal end of the humerus. It serves as a deep indentation that specifically accommodates the olecranon process of the ulna, particularly during the extension of the elbow joint. When the arm is fully extended, the olecranon process fits snugly into this fossa, allowing for a smooth and stable motion. This anatomical arrangement plays an essential role in enabling the elbow's full range of motion while providing structural support and preventing dislocation.

In contrast, the coronoid fossa, located above the olecranon fossa on the anterior side of the humerus, accommodates the coronoid process of the ulna during elbow flexion, but it is not related to extension. The radial notch is a feature of the ulna that articulates with the head of the radius, allowing for rotation but does not directly engage with the olecranon process. The trochlea is another part of the humerus that articulates with the ulna, assisting in flexion and extension; however, it does not specifically accommodate the olecranon process in the same way as the olecranon fossa.