Which bone is the long medial bone in the antebrachial region?

The ulna is the long medial bone in the antebrachial region, which is the area of the forearm. In anatomical terms, "medial" refers to the position closer to the midline of the body, while "lateral" refers to the position farther away from the midline. The ulna runs parallel to the radius but is located on the inner side of the forearm, making it the medial bone in this region.

The ulna is also longer than the radius in adults, and it plays a key role in forming the elbow joint, connecting with the humerus at its proximal end. Its physical orientation helps with movements of the forearm and wrist, particularly in bending the arm at the elbow.

In contrast, the radius is the lateral bone of the forearm, and both the humerus and scapula are not part of the antebrachial region, as the humerus is located in the upper arm and the scapula is part of the shoulder girdle. Thus, the ulna is correctly identified as the long medial bone in the antebrachial region.