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Capitate
The capitate bone is a bone in the human wrist found in the center of the carpal bone region, located at the distal end of the radius and ulna bones. It articulates with the third metacarpal bone (the middle finger) and forms the third carpometacarpal joint. The capitate bone is the largest of the carpal bones in the human hand. 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.''Gray's Anatomy'' (1918). See infobox. The bone is also found in many other mammals, and is homologous with the "third distal carpal" of reptiles and amphibians. Structure The capitate is the largest carpal bone found within the hand. The capitate is found within the distal row of carpal bones. The capitate lies directly adjacent to the metacarpal of the ring finger on its distal surface, has the hamate on its ulnar surface and trapezoid on its radial surface, and abuts the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carpal Bones
The carpal bones are the eight small bones that make up the wrist (carpus) that connects the hand to the forearm. The terms "carpus" and "carpal" are derived from the Latin wikt:carpus#Latin, carpus and the Greek language, Greek wikt:καρπός#Ancient Greek, καρπός (karpós), meaning "wrist". In human anatomy, the main role of the carpal bones is to joint, articulate with the radius (bone), radial and ulnar heads to form a highly mobile condyloid joint (i.e. wrist joint),Kingston 2000, pp 126-127 to provide attachments for thenar and hypothenar muscles, and to form part of the rigid carpal tunnel which allows the median nerve and tendons of the anterior compartment of the forearm, anterior forearm muscles to be transmitted to the hand and fingers. In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius (bone), radius and ulna and the metacarpus. The bones of the carpus do not belong to individual fingers (or toes in quadrupeds), whereas those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carpal Bone
The carpal bones are the eight small bones that make up the wrist (carpus) that connects the hand to the forearm. The terms "carpus" and "carpal" are derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the carpal bones is to articulate with the radial and ulnar heads to form a highly mobile condyloid joint (i.e. wrist joint),Kingston 2000, pp 126-127 to provide attachments for thenar and hypothenar muscles, and to form part of the rigid carpal tunnel which allows the median nerve and tendons of the anterior forearm muscles to be transmitted to the hand and fingers. 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 (or toes in quadrupeds), whereas those of the metacarpus do. The corresponding part of the foot is the tarsus. The carpal bones allow the wrist to move and rotate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal bones." (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as ''wrist joints''. "With the large number of bones composing the wrist (ulna, radius, eight carpas, and five metacarpals), it makes sense that there are many, many joints that make up the structure known as the wrist." This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum. As a consequence of these various definitions, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the Koala#Characteristics, koala (which has two thumb#Opposition and apposition, opposable thumbs on each "hand" and fingerprints extremely similar to human fingerprints) are often described as having "hands" instead of paws on their front limbs. The raccoon is usually described as having "hands" though opposable thumbs are lacking. Some evolutionary anatomists use the term ''hand'' to refer to the appendage of digits on the forelimb more generally—for example, in the context of whether the three Digit (anatomy), digits of the bird hand involved the same Homology (biology), homologous loss of two digits as in the dinosaur hand. The human hand usually has five digits: Finger numbering#Four-finger system, four fingers plus one thumb; however, these are often referred to collectively as Finger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trapezoid Bone
The trapezoid bone (lesser multangular bone) is a carpal bone in tetrapods, including humans. It is the smallest bone in the distal row of carpal bones that give structure to the palm of the hand. 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 other, and separated by sharp edges. It is homologous with the "second distal carpal" of reptiles and amphibians. Structure The trapezoid is a four-sided carpal bone found within the hand. The trapezoid is found within the distal row of carpal bones. Surfaces The '' superior surface'', quadrilateral, smooth, and slightly concave, articulates with the scaphoid. The '' inferior surface'' articulates with the proximal end of the second metacarpal bone; it is convex from side to side, concave from before backward and subdivided by an elevated ridge into two unequal facets. The ''dorsal'' and '' palmar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaphoid Bone
The scaphoid bone is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew nut. Structure The scaphoid is situated between the proximal and distal rows of carpal bones. It is located on the radial side of the wrist, adjacent to the styloid process of the radius. It articulates with the radius, lunate, trapezoid, trapezium, and capitate. Over 80% of the bone is covered in articular cartilage. Bone The palmar surface of the scaphoid is concave, and forming a distal tubercle, giving attachment to the transverse carpal ligament. The proximal surface is triangular, smooth and convex. The lateral surface is narrow and gives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaphoid
The scaphoid bone is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew nut. Structure The scaphoid is situated between the proximal and distal rows of carpal bones. It is located on the radial side of the wrist, adjacent to the styloid process of the radius. It articulates with the radius, lunate, trapezoid, trapezium, and capitate. Over 80% of the bone is covered in articular cartilage. Bone The palmar surface of the scaphoid is concave, and forming a distal tubercle, giving attachment to the transverse carpal ligament. The proximal surface is triangular, smooth and convex. The lateral surface is narrow and gives attachm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamate Bone
The hamate bone (from Latin hamatus, "hooked"), or unciform bone (from Latin '' uncus'', "hook"), Latin os hamatum and occasionally abbreviated as just hamatum, is a bone in the human wrist readily distinguishable by its wedge shape and a hook-like process ("hamulus") projecting from its palmar surface. Structure The hamate is an irregularly shaped carpal bone found within the hand. The hamate is found within the distal row of carpal bones, and abuts the metacarpals of the little finger and ring finger. Adjacent to the hamate on the ulnar side, and slightly proximal and ulnar to it, is the pisiform bone. Adjacent on the radial side is the capitate, and proximal is the lunate bone. Surfaces The hamate bone has six surfaces: * The ''superior'', the apex of the wedge, is narrow, convex, smooth, and articulates with the lunate. * The ''inferior'' articulates with the fourth and fifth metacarpal bones, by concave facets which are separated by a ridge. * The ''dorsal'' is triangul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamate
The hamate bone (from Latin language, Latin wiktionary:hamatus, hamatus, "hooked"), or unciform bone (from Latin language, Latin ''wikt:uncus, uncus'', "hook"), Latin os hamatum and occasionally abbreviated as just hamatum, is a bone in the human wrist readily distinguishable by its wedge shape and a hook-like process ("hamulus") projecting from its Radioulnar, palmar surface. Structure The hamate is an irregularly shaped carpal bone found within the hand. The hamate is found within the distal row of carpal bones, and abuts the metacarpals of the little finger and ring finger. Adjacent to the hamate on the ulnar side, and slightly proximal and ulnar to it, is the pisiform bone. Adjacent on the radial side is the capitate, and proximal is the lunate bone. Surfaces The hamate bone has six surfaces: * The ''superior'', the apex of the wedge, is narrow, convex, smooth, and articulates with the lunate bone, lunate. * The ''inferior'' articulates with the fourth and fifth metacarpal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
