Lunate bone
Encyclopedia
The lunate bone is a carpal bone (wrist bone) in the human
hand
that may be distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row of the carpus
(wrist
) region between the fore arm and hand (manus). In standard medical posture, the lunate carpal bone is situated between the lateral Scaphoid bone and medial Triquetral bone. The lunate carpal bone straddles distally the bordering ulna and radius bones and proximally to distal carpus
(wrist) Trapezium bone and Trapezoid bone
.
The etymology of the Lunate bone derives from the Latin luna which means "moon", the lunate bone looks semi-similar to a crescent moon. In amphibians and reptiles, the bone is instead referred to as the intermedium, because of its position between the other two proximal carpals.
.
The inferior surface is deeply concave, and of greater extent from before backward than transversely: it articulates with the head of the capitate, and, by a long, narrow facet (separated by a ridge from the general surface), with the hamate.
The dorsal and palmar surfaces are rough, for the attachment of ligaments, the former being the broader, and of a somewhat rounded form.
The lateral surface presents a narrow, flattened, semilunar facet for articulation with the scaphoid.
The medial surface is marked by a smooth, quadrilateral facet, for articulation with the triangular bone.
Human
Humans are the only living species in the Homo genus...
hand
Hand
A hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs...
that may be distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row of the carpus
Carpus
In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius and ulna and the metacarpus. The bones of the carpus do not belong to individual fingers , whereas those of the metacarpus do. The corresponding part of the foot is the tarsus...
(wrist
Wrist
In human anatomy, the wrist is variously defined as 1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand;...
) region between the fore arm and hand (manus). In standard medical posture, the lunate carpal bone is situated between the lateral Scaphoid bone and medial Triquetral bone. The lunate carpal bone straddles distally the bordering ulna and radius bones and proximally to distal carpus
Carpus
In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius and ulna and the metacarpus. The bones of the carpus do not belong to individual fingers , whereas those of the metacarpus do. The corresponding part of the foot is the tarsus...
(wrist) Trapezium bone and Trapezoid bone
Trapezoid bone
The trapezoid bone is a carpal bone in tetrapods, including humans. It is the smallest bone in the distal row. It may be known by its wedge-shaped form, the broad end of the wedge constituting the dorsal, the narrow end the palmar surface; and by its having four articular facets touching each...
.
The etymology of the Lunate bone derives from the Latin luna which means "moon", the lunate bone looks semi-similar to a crescent moon. In amphibians and reptiles, the bone is instead referred to as the intermedium, because of its position between the other two proximal carpals.
Surfaces
The superior surface, convex and smooth, articulates with the radiusRadius (bone)
The radius is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna, which exceeds it in length and size. It is a long bone, prism-shaped and slightly curved longitudinally...
.
The inferior surface is deeply concave, and of greater extent from before backward than transversely: it articulates with the head of the capitate, and, by a long, narrow facet (separated by a ridge from the general surface), with the hamate.
The dorsal and palmar surfaces are rough, for the attachment of ligaments, the former being the broader, and of a somewhat rounded form.
The lateral surface presents a narrow, flattened, semilunar facet for articulation with the scaphoid.
The medial surface is marked by a smooth, quadrilateral facet, for articulation with the triangular bone.
Clinical relevance
The lunate bone is the most frequently dislocated carpal bone.- Kienbock's diseaseKienbock's diseaseKienbock's disease is a disorder of the wrist. It is named for Dr. Robert Kienböck, a radiologist in Vienna, Austria who described osteomalacia of the lunate in 1910....