The capitate bone is the largest of the carpal bones in the human hand, and occupies the center of the wrist. It presents, above, a rounded portion or head, which is received into the concavity formed by the scaphoid and lunate bones; a constricted portion or neck; and below this, the body. The bone is also found in many other mammals, and is homologous with the "third distal carpal" of reptiles and amphibians. Surfaces The superior surface is round, smooth, and articulates with the lunate bone. The inferior surface is divided by two ridges into three facets, for articulation with the second, third, and fourth metacarpal bones, that for the third being the largest. The dorsal surface is broad and roughened by the attachment of ligaments. It is wider than the narrow ventral surface that has a distinct prominence. The palmar surface is narrow, rounded, and rough, for the attachment of ligaments and a part of the adductor pollicis muscle. The lateral surface articulates with the lesser multangular by a small facet at its anterior inferior angle, behind which is a rough depression for the attachment of an interosseous ligament. Above this is a deep, rough groove, forming part of the neck, and serving for the attachment of ligaments; it is bounded superiorly by a smooth, convex surface, for articulation with the scaphoid bone. The medial surface articulates with the hamate bone by a smooth, concave, oblong facet, which occupies its posterior and superior parts; it is rough in front, for the attachment of an interosseous ligament. Articulations The capitate articulates with seven bones: the scaphoid and lunate proximally, the second metacarpal, third metacarpal, and fourth metacarpal distally, the lesser multangular on the radial side, and the hamate on the ulnar side.