The third metacarpal bone (metacarpal bone of the
middle finger
The middle finger, long finger, second finger, third finger, toll finger or tall man is the third digit of the human hand, located between the index finger and the ring finger. It is typically the longest digit. In anatomy, it is also called ...
) is a little smaller than the second.
The dorsal aspect of its base presents on its radial side a pyramidal eminence, the
styloid process, which extends upward behind the
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 carpomet ...
; immediately distal to this is a rough surface for the attachment of the
extensor carpi radialis brevis muscle
In human anatomy, extensor carpi radialis brevis is a muscle in the forearm that acts to extend and abduct the wrist. It is shorter and thicker than its namesake extensor carpi radialis longus which can be found above the proximal end of the exten ...
.
The carpal articular facet is concave behind, flat in front, and articulates with the capitate.
On the radial side is a smooth, concave facet for articulation with the
second metacarpal
The second metacarpal bone (metacarpal bone of the index finger) is the longest, and its base the largest, of all the metacarpal bones.''Gray's Anatomy'' (1918). See infobox.
Human anatomy
Its base is prolonged upward and medialward, forming a ...
, and on the ulnar side two small oval facets for the
fourth metacarpal
The fourth metacarpal bone (metacarpal bone of the ring finger) is shorter and smaller than the third.
The base is small and quadrilateral; its superior surface presents two facets, a large one medially for articulation with the hamate, and a sma ...
.
Ossification
The ossification process begins in the shaft during prenatal life, and in the head between 11th and 27th months.
Additional images
File:Third metacarpal bone (left hand) - animation01.gif, Third metacarpal bone of the left hand (shown in red). Animation.
File:Third metacarpal bone (left hand) - animation02.gif, Third metacarpal bone of the left hand. Close up.
File:Gray219 - Third metacarpal bone.png, Palmer view of the left hand (third metacarpal shown in yellow).
File:Gray220 - Third metacarpal bone.png, Dorsal view of the left hand (third metacarpal shown in yellow).
See also
*
Metacarpus
In human anatomy, the metacarpal bones or metacarpus form the intermediate part of the skeletal hand located between the phalanges of the fingers and the carpal bones of the wrist, which forms the connection to the forearm. The metacarpal bones ...
*
First metacarpal bone
The first metacarpal bone or the metacarpal bone of the thumb is the first bone proximal to the thumb. It is connected to the trapezium of the carpus at the first carpometacarpal joint and to the proximal thumb phalanx at the first metacarpophala ...
*
Second metacarpal bone
The second metacarpal bone (metacarpal bone of the index finger) is the longest, and its base the largest, of all the metacarpal bones.''Gray's Anatomy'' (1918). See infobox.
Human anatomy
Its base is prolonged upward and medialward, forming a ...
*
Fourth metacarpal bone
The fourth metacarpal bone (metacarpal bone of the ring finger) is shorter and smaller than the third.
The base is small and quadrilateral; its superior surface presents two facets, a large one medially for articulation with the hamate, and a sma ...
*
Fifth metacarpal bone
The fifth metacarpal bone (metacarpal bone of the little finger or pinky finger) is the most medial and second-shortest of the metacarpal bones.
Surfaces
It presents on its base one facet on its superior surface, which is concavo-convex and artic ...
References
Skeletal system
Bones of the hand
Metacarpus
{{Portal bar, Anatomy