| Vomer | |
|---|---|
 Vomer labeled at left. | |
 Bones and cartilages of septum of nose. Right side. (Vomer visible at bottom left.) | |
| Details | |
| Identifiers | |
| Latin | vomer |
| MeSH | D055172 |
| TA98 | A02.1.11.001 |
| TA2 | 751 |
| FMA | 9710 |
| Anatomical terms of bone | |
Thevomer (/ˈvoʊmər/;[1][2]Latin:vomer,lit. 'ploughshare') is one of the unpairedfacial bones of theskull. It is located in the midsagittal line, andarticulates with thesphenoid, theethmoid, the left and rightpalatine bones, and the left and rightmaxillary bones. The vomer forms the inferior part of thenasal septum in humans, with the superior part formed by theperpendicular plate of the ethmoid bone.[3] The name is derived from the Latin word for a ploughshare and the shape of the bone.
The vomer is situated in the median plane, but its anterior portion is frequently bent to one side.
It is thin, somewhat quadrilateral in shape, and forms the hinder and lower part of thenasal septum; it has two surfaces and four borders.
The surfaces are marked by small furrows forblood vessels, and on each is thenasopalatine groove, which runs obliquely downward and forward, and lodges thenasopalatine nerve and vessels.
Thesuperior border, the thickest, presents a deep furrow, bounded on either side by a horizontal projecting expansion of bone – calledthe wing of vomer; the furrow receives therostrum of thesphenoid, while the margins of the alae articulate with the vaginal processes of themedial pterygoid plates of the sphenoid behind, and with the sphenoidal processes of the palatine bones in front.
Theinferior border articulates with the crest formed by the maxillæ andpalatine bones.
Theanterior border is the longest and slopes downward and forward. Its upper half is fused with theperpendicular plate of theethmoid; its lower half is grooved for the inferior margin of theseptal cartilage of the nose.
Theposterior border is free of bony articulation, having no muscle attachments. It is concave, separates thechoanae, and is thick and bifid above, thin below.
The human vomerarticulates with six bones:
It also articulates with the septal cartilage of the nose.
Thevomeronasal organ, also called Jacobson's organ, is achemoreceptor organ named for its closeness to the vomer andnasal bones, and is particularly developed in animals such as cats (who adopt a characteristic pose called theFlehmen reaction orflehming when making use of it), and is thought to have to do with the perception of certainpheromones.
Inbony fish, the vomers are flattened, paired, bones forming the anterior part of the roof of the mouth, just behind thepremaxillary bones. In many species, they have teeth, supplementing those in the jaw proper; in somelabyrinthodonts (extinct amphibians) the teeth on the vomers were actually larger than the primary set. Inamphibians andreptiles, the vomers become narrower, due to the presence of the enlargedchoanae (the inner part of the nostrils) on either side, and they may extend further back in the jaw. They are typically small inbirds, where they form the upper hind part of the beak, again being located between the choanae.[4]
In some livingsalamanders, including themudpuppy, themaxilla is absent and therefore the vomerine teeth fulfill a major functional role in the upper jaw.[5]
Inmammals, the vomers have become narrower still, and are fused into a single, vertically oriented bone. The development of thehard palate beneath the vomer means that the bone is now located in a nasal chamber, separate from the mouth.[4]
This article incorporates text in thepublic domain frompage 170 of the 20th edition ofGray's Anatomy(1918)
