Olfactory epithelium 640819 207322548 2008-04-22T09:29:39Z Chphe 4343522 +[[fr:Épithélium olfactif]] {{Infobox Anatomy | Name = Olfactory epithelium | Latin = | GraySubject = 223 | GrayPage = 996 | Image = Gray857.png | Caption = Section of the olfactory mucous membrane. | Image2 = Gray772.png | Caption2 = Plan of olfactory neurons. | System = | MeshName = Olfactory+Mucosa | MeshNumber = A04.531.520.573 | }} The '''olfactory epithelium''' is a specialized [[epithelium|epithelial]] tissue inside the [[nasal cavity]] that is involved in [[olfaction|smell]]. In humans, it measures about 2 cm by 5 cm long (about 1 inch wide by 2 inches) and lies on the roof of the nasal cavity about 3 inches (about 7 cm) above and behind the nostrils. The olfactory epithelium is the part of the [[olfactory system]] directly responsible for detecting [[odor]]s. Olfactory epithelium consists of three distinct types of cells: Olfactory cells, supporting cells, and basal cells The olfactory cells of the epithelium are bipolar neurons which congregate to form the [[olfactory nerve]] (cranial nerve I). The apical poles of these neurons are ciliated and coated with a serous secretion from [[Bowman's glands]] located in the [[lamina propria]]. Analogous to neural glial cells, the supporting cells of the olfactory epithelium function as metabolic and physical support for the olfactory cells. Histologically, the supporting cells are tall columnar cells featuring [[microvilli]] and a prominent [[terminal web]]. The nuclei of supporting cells are more apically located than those of the other olfactory epithelial cells. Resting on the basal lamina of the olfactory epithelium, basal cells are stem cells capable of division and differentiation into either supporting or olfactory cells. The constant divisions of the basal cells leads to the olfactory epithelium being replaced every 2-4 weeks. Basal cells can be divided on the basis of cellular anatomy histological markers into two populations: the horizontal basal cells which line the olfactory epithelium and the slightly more superficial globose basal cells. Globose basal cells are thought to be the primary stem cell population supplying new cells in this system. The olfactory epithelium can be damaged by inhalation of toxic fumes, physical injury to the interior of the nose, and possibly by the use of some nasal sprays. Because of its regenerative capacity, damage to the olfactory epithelium can be temporary but in extreme cases, injury can be permanent, leading to [[anosmia]]. ==External links== * {{YaleCranialNerves|1|2}} * [http://www.tufts.edu/sackler/cmdb/olfactory.htm Diagram of Olfactory Epithelium Tufts Sackler] {{Olfactory_system}} {{Epithelial tissue}} {{Commons|Category:Olfactory epithelium}} [[Category:Olfactory system]] [[fa:روپوشه بویایی]] [[fr:Épithélium olfactif]] [[pt:Epitélio olfatório]]