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Encyclopedia > Carpometacarpal joint
Carpometacarpal joint
Human hand bones
Ligaments of wrist. Posterior view.
Latin articulationes carpometacarpeæ
Gray's subject #88 330
Dorlands/Elsevier a_64/12161025

The carpometacarpal joint refers to the articulations between the carpal bones and the metacarpals. Image File history File links Human_hand_bones_simple. ... Image File history File links Gray335. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... Elseviers logo. ... In human anatomy, the carpal bones are the bones of the human wrist. ... The metacarpus is the intermediate part of the hand skeleton that is located between the fingers distally and the carpus which forms the connection to the forearm. ...

Contents

Carpometacarpal Articulation of the Thumb

This is a joint of reciprocal reception between the first metacarpal and the trapezium; it enjoys great freedom of movement on account of the configuration of its articular surfaces, which are saddle-shaped. The metacarpus is the intermediate part of the hand skeleton that is located between the fingers distally and the carpus which forms the connection to the forearm. ... The term trapezium can mean more than one thing: In human anatomy, trapezium is a bone in the hand In geometry, a trapezium is also a name for a class of quadrilaterals. ...


The joint is surrounded by a capsule, which is thick but loose, and passes from the circumference of the base of the metacarpal bone to the rough edge bounding the articular surface of the greater trapezium; it is thickest laterally and dorsally, and is lined by synovial membrane. The synovium or synovial membrane is a thin, weak layer of tissue which lines the non-cartilaginous surfaces within the joint space, sealing it from the surrounding tissue. ...


Movements

In this articulation the movements permitted are flexion and extension in the plane of the palm of the hand, abduction and adduction in a plane at right angles to the palm, circumduction, and opposition.


It is by the movement of opposition that the tip of the thumb is brought into contact with the volar surfaces of the slightly flexed fingers.


This movement is effected through the medium of a small sloping facet on the anterior lip of the saddle-shaped articular surface of the greater multangular.


The flexor muscles pull the corresponding part of the articular surface of the metacarpal bone on to this facet, and the movement of opposition is then carried out by the adductors.


Flexion of this joint is produced by the flexor pollicis longus and brevis, assisted by the opponens pollicis and the adductor pollicis. The Flexor pollicis longus muscle is a muscle of the human body. ... The Opponens pollicis muscle is a muscle of the human body. ... The Adductor pollicis muscle is a muscle of the human body. ...


Extension is effected mainly by the abductor pollicis longus, assisted by the Extensores pollicis longus and brevis. The Abductor pollicis longus muscle is a muscle of the human body. ...


Adduction is carried out by the Adductor; abduction mainly by the abductor pollicis longus and brevis, assisted by the extensors.


Articulations of the Other Four Metacarpal Bones with the Carpus

The joints between the carpus and the second, third, fourth, and fifth metacarpal bones are arthrodial.


The bones are united by dorsal, volar, and interosseous ligaments.


Dorsal ligaments

See dorsal carpometacarpal ligaments

The dorsal carpometacarpal ligaments, the strongest and most distinct carpometacarpal ligaments, connect the carpal and metacarpal bones on their dorsal surfaces. ...

Volar ligaments

See palmar carpometacarpal ligaments

The palmar carpometacarpal ligaments (or volar) have a somewhat similar arrangement to the dorsal carpometacarpal ligaments, with the exception of those of the third metacarpal, which are three in number: a lateral one from the greater multangular, situated superficial to the sheath of the tendon of the Flexor carpi radialis...

The Interosseous Ligaments

The interosseous ligaments consist of short, thick fibers, and are limited to one part of the carpometacarpal articulation; they connect the contiguous inferior angles of the capitate and hamate with the adjacent surfaces of the third and fourth metacarpal bones.


Synovial Membrane

The synovial membrane is a continuation of that of the intercarpal joints. Occasionally, the joint between the hamate and the fourth and fifth metacarpal bones has a separate synovial membrane.


The synovial membranes of the wrist and carpus are thus seen to be five in number.

  • The first passes from the lower end of the ulnar to the ulnar notch of the radius, and lines the upper surface of the articular disk.
  • The second passes from the articular disk and the lower end of the radius above, to the bones of the first row below.
  • The third, the most extensive, passes between the contiguous margins of the two rows of carpal bones, and sometimes, in the event of one of the interosseous ligaments being absent, between the bones of the second row to the carpal extremities of the second, third, fourth, and fifth metacarpal bones.
  • The fourth extends from the margin of the greater multangular to the metacarpal bone of the thumb.
  • The fifth runs between the adjacent margins of the triangular and pisiform bones.

Occasionally the fourth and fifth carpometacarpal joints have a separate synovial membrane. Circle illustration In classical geometry, a radius (plural: radii) of a circle or sphere is any line segment from its center to its boundary. ... // This digit is one of the five fingers (though the word finger can also refer exclusively to the non-thumb digits). ...


Movements

The movements permitted in the carpometacarpal articulations of the fingers are limited to slight gliding of the articular surfaces upon each other, the extent of which varies in the different joints.


The metacarpal bone of the little finger is most movable, then that of the ring finger; the metacarpal bones of the index and middle fingers are almost immovable. The ring finger on this hand is extended. ... The Index finger The index finger, pointer finger or forefinger is the second digit of a human hand, located between the thumb and the middle finger. ... This article is about the vulgar gesture. ...


External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant. The University of Kansas (often referred to as KU) is an institution of higher learning in Lawrence, Kansas. ... The University of Kansas (often referred to as KU) is an institution of higher learning in Lawrence, Kansas. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body (or Grays Anatomy as it has more commonly become known) is an anatomy textbook widely regarded as a classic work on human anatomy. ...


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