The third metatarsal bone is a
long bone in the foot. It is the second longest
metatarsal
The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the med ...
. The longest being the
second metatarsal. The third metatarsal is analogous to the
third metacarpal bone 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 ligaments. 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 roots, describe something in its standard anatomical position. This position prov ...
extremity articulates with the third proximal phalanx
The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones ...
.
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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