Final answer:
The smallest carpal bone is the pisiform, which articulates with the anterior surface of the triquetrum bone in the wrist.
Step-by-step explanation:
The smallest carpal bone in the human wrist is the pisiform bone. This pea-shaped bone is located in the proximal row of the carpal bones, which are the bones that form the wrist and base of the hand. The proximal row consists of the scaphoid, lunate, triquetrum, and pisiform bones. Particularly, the pisiform rests upon the anterior surface of the triquetrum bone.
It is positioned medially and can be felt as a bony bump at the base of the hand near the pinky side. The arrangement of these carpal bones is essential for wrist mobility and stability, and remembering their layout can be aided by the mnemonic 'So Long To Pinky, Here Comes The Thumb', which starts on the lateral side with the scaphoid and ends on the medial side with the pisiform bone. As for the distal row, it follows the pattern from medial to lateral with the hamate, capitate, trapezoid, and trapezium bones.