Carpal bone

There are eight of them altogether, and they can be thought of as forming two rows of four.

Proximal Row

• Scaphoid (or navicular) - this bone, with the lunate, articulates with the radius of the arm.
• Lunate - articulates with the radius and the capitate.
• Triquetrum - on the ulnar side of the hand, but does not articulate with the ulna.
• Pisiform - a sesamoid bone that lies anterior to (closer to the palm than) the triquetrum.

Distal Row

• Trapezium - the most lateral bone of this row. It articulates with the metacarpal of the thumb.
• Trapezoid - articulates with the 2nd metacarpal.
• Capitate - articulates with the metacarpal of the middle finger.
• Hamate - articulates with the metacarpals of the 4th and 5th fingers. It has a projection called a hook.