Final answer:
The Trochlear notch is also known as the semilunar notch; a feature of the ulna bone participating in elbow joint articulation.
Step-by-step explanation:
The Trochlear notch is also known as the semilunar notch. It is a large, C-shaped depression located on the anterior side of the proximal ulna bone and articulates at the elbow with the trochlea of the humerus. This notch allows for the flexion and extension movement of the forearm at the elbow joint. It is distinct from other depressions and processes such as the coronoid fossa, radial fossa, olecranon fossa, and the coronoid process of the ulna, which all play different roles in the anatomy of the elbow and forearm.