- Source: Metacarpophalangeal joint
The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the fingers. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow cavities on the proximal ends of the proximal phalanges. Being condyloid, they allow the movements of flexion, extension, abduction, adduction and circumduction (see anatomical terms of motion) at the joint.
Structure
= Ligaments
=Each joint has:
palmar ligaments of metacarpophalangeal articulations
collateral ligaments of metacarpophalangeal articulations
= Dorsal surfaces
=The dorsal surfaces of these joints are covered by the expansions of the Extensor tendons, together with some loose areolar tissue which connects the deep surfaces of the tendons to the bones.
Function
The movements which occur in these joints are flexion, extension, adduction, abduction, and circumduction; the movements of abduction and adduction are very limited, and cannot be performed while the fingers form a fist.
The muscles of flexion and extension are as follows:
Clinical significance
Arthritis of the MCP is a distinguishing feature of rheumatoid arthritis, as opposed to the distal interphalangeal joint in osteoarthritis.
= Other animals
=In many quadrupeds, particularly horses and other larger animals, the metacarpophalangeal joint is referred to as the "fetlock". This term is translated literally as "foot-lock". In fact, although the term fetlock does not specifically apply to other species' metacarpophalangeal joints (for instance, humans), the "second" or "mid-finger" knuckle of the human hand does anatomically correspond to the fetlock on larger quadrupeds. For lack of a better term, the shortened name may seem more practical.
See also
Knuckle
References
This article incorporates text in the public domain from page 332 of the 20th edition of Gray's Anatomy (1918)
External links
Hand kinesiology at the University of Kansas Medical Center
EatonHand joi-047
Kata Kunci Pencarian:
- Buku-buku jari
- Metacarpophalangeal joint
- Dorsal interossei of the hand
- Collateral ligaments of metacarpophalangeal joints
- Palmar plate
- Interphalangeal joints of the hand
- Joint cracking
- Biaxial joint
- Condyloid joint
- Metacarpal bones
- Lumbricals of the hand
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