Capitate bone

Bone: Capitate bone
Shown is the right hand, palm down (left) and palm up (right). Proximal: A=Scaphoid, B=Lunate, C=Triquetral, D=Pisiform Distal: E=Trapezium, F=Trapezoid, G=Capitate, H=Hamate
The left capitate bone
Latin	os capitatum; os magnum
Gray's	subject #54 226
MeSH	Capitate+Bone

In the human hand, the capitate bone is the largest of the carpal bones, 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. ^[1] The bone is also found in many other mammals, and is homologous with the "third distal carpal" of reptiles and amphibians.

The etymology derives from the Latin capitātus, "having a head," from capit-, meaning "head."

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 rough.

The volar 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 navicular.

The medial surface articulates with the hamate 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.

^[1]

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. ^[1]

See also

• Bone terminology
• Terms for anatomical location

Additional images

Capitate bone.   Os capitatum of the left hand, palmar surface   Os capitatum of the left hand, dorsal surface   Bones of the left hand. Volar surface.   Bones of the left hand. Dorsal surface.   Transverse section across the wrist and digits.

References

1. ^ ^{a b c} Gray's Anatomy (1918). See infobox.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.