The third metatarsal bone is a
long bone
The long bones are those that are longer than they are wide. They are one of five types of bones: long, short, flat, irregular and sesamoid. Long bones, especially the femur and tibia, are subjected to most of the load during daily activities ...
in the foot. It is the second longest
metatarsal. The longest being the
second metatarsal. The third metatarsal is analogous to the
third metacarpal bone
The third metacarpal bone (metacarpal bone of the middle finger) 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 ...
in the hand
As the four other metatarsals bones it can be divided into three parts; base, body and head.
The base is the part closest to the ankle and the head is closest to the toes. The narrowed part in the middle is referred to as the body of the bone. The bone is somewhat flatten giving it two surfaces; the plantar (towards the
sole of the foot) and the dorsal side (the area facing upwards while standing).
[ These surfaces are rough for the attachment of ]ligament
A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the:
* Peritoneal l ...
s. The bone is curved longitudinally, so as to be concave below, slightly convex above.
The base or posterior extremity is wedge-shaped.[
The third metatarsal bone articulates proximally, by means of a triangular smooth surface, with the third cuneiform; medially, by two facets, with the second metatarsal; and laterally, by a single facet, with the fourth metatarsal. This last facet is situated at the dorsal angle of the base.
The head or ]anterior
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...
extremity articulates with the third proximal phalanx.
Muscle attachments
The second and third dorsal interossei muscles attaches to the third metatarsal bone. The second dorsal interossei from the medial side of the bone and the third dorsal interossei from the lateral side. The function of the muscle is to spread the toes.[
The horizontal head of the adductor hallucis also originates from the lateral side of the metacarpophalangeal joint and from the deep transverse metatarsal ligament,][ a narrow band which runs across and connects together the heads of all the metatarsal bones.
]
Additional images
File:Footx.jpg, X-ray of foot, showing phalangeal fracture
File:Gray290.png, Skeleton of foot. Medial aspect.
File:Gray360.png, Oblique section of left intertarsal and tarsometatarsal articulations, showing the synovial cavities.
File:Foot bones - tarsus, metatarsus.jpg, Foot bones - tarsus, metatarsus
File:Foot bones - metatarsus and phalanges.jpg, Foot bones - metatarsus and phalanges
File:Metatarsus.jpg, Metatarsus
References
Bones of the lower limb
Bones of the foot
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