Final answer:
The wrist joint is formed by the distal end of the radius and carpal bones, not the distal end of the ulna, which indirectly contributes to the joint. The ulna is connected to the carpal bones via a fibrocartilaginous pad, not by articulation with the carpal bones directly.
Step-by-step explanation:
The wrist joint consists of the ends of the radius and ulna bones of the forearm with the carpal bones on the hand. This statement is partially true, but it's important to be specific about the relationships between these bones at the wrist joint. The wrist is a complex structure that includes the distal end of the radius, and carpal bones, but not the distal end of the ulna, which does not directly articulate with the carpal bones at the radiocarpal joint. Instead, the distal ulnar articulates with a fibrocartilaginous pad that spans the space between the ulna and the carpal bones.
The eight carpal bones form the base of the hand and are arranged into proximal and distal rows. Three of these carpal bones (scaphoid, lunate, and triquetrum) contribute to the radiocarpal joint. The scaphoid and lunate bones articulate directly with the distal end of the radius to form this joint. Therefore, while the radius plays a crucial role in forming the wrist joint with carpal bones, the ulna contributes indirectly through a fibrocartilaginous pad rather than a direct bone-to-bone articulation.