Final answer:
The ulna and radius are two bones in the forearm distinguishable by their location and distinctive features. The ulna is on the medial side with a C-shaped trochlear notch, while the radius is lateral with a disc-shaped head and articulates with the carpal bones.
Step-by-step explanation:
Differentiating Between the Ulna and Radius
Two bones make up the forearm, the ulna and the radius. The ulna is located on the medial side of the forearm, while the radius is situated on the lateral side, near the thumb. One of the easiest ways to differentiate them is by their location in relation to the body and their distinct features.
The ulna has a large, C-shaped trochlear notch at the proximal end, which articulates with the humerus, and a pointed styloid process at the distal end. Additionally, the olecranon process forms the bony tip of the elbow. On the other hand, the radius features a disc-shaped head at the proximal end and the radial tuberosity below the neck, which is a muscle attachment point. The distal end of the radius articulates with the carpal bones to form the wrist joint.
Both bones are connected by an interosseous membrane and capable of movements such as supination and pronation. Supination is when the palm faces upwards, and the bones are parallel, while pronation is when the palm faces downwards, and the bones form an X-shape.