Olfactory Mucosa
Olfactory mucosa lines the roof of the nasal cavity and superior conchae (= turbinates) and is structurally modified to detect odor-producing chemicals (= odorants).
In the epithelium of the olfactory mucosa, are millions of specialized nerve cells called olfactory receptors. The odorant-sensitive tips of the receptors protrude into the nasal cavity from the free surface of the epithelium. Several non-motile cilia extend from each bulbous tip. Along in the cilia are many binding sites for odorants.
Surrounding the receptors are many elongated supporting cells or sustentacular cells. A thin layer of watery mucus made by the supporting cells and Bowman's (olfactory) glands covers the receptor cilia and microvilli. During inhalation, ordorants are drawn into this fluid layer, where they dissolve and then bind to the cilia receptors. Binding of the odorants causes the olfactory receptors to generate electro-chemical impulses (= action potentials). Receptor axons carry the impulses through the holes in the cribiform plate to the olfactory bulbs at the base of the brain.
