Olfactory epithelium: structure and function

Author: Scott A. Sheffield MS

Last update:

An introduction to the Olfactory Mucosa:

image descriptionOlfactory mucosa lines the roof of the nasal cavity and superior turbinates (= nasal conchae) and is structurally modified to detect odor-producing chemicals (= odorants).

A midsagittal view and zoom-in of the olfactory mucosa
Olfactory Mucosa highlighted and labeled in midsagittal view
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  • An image descriptionexpanded view  of the olfactory mucosa shows more detail about its layered composition.
A midsagittal view and zoom-in of the olfactory mucosa
A zoom-in view of the olfactory mucosa
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  • In the epithelium layer are millions of specialized nerve cells referred to as image descriptionolfactory receptors. The odorant-sensitive tips of the receptors protrude into the nasal cavity from the free surface of the epithelium. Several non-motile image descriptioncilia  extend from each bulbous tip. Along the cilia are many binding sites for odorants. Surrounding the receptors are many elongated image descriptionsupporting cells or sustentacular cells.

Have you been making any of these common anatomy learning mistakes?

A zoom-in view of the olfactory mucosa unlabeled
A zoom-in view of the olfactory mucosa demonstrating the supporting cells
A zoom-in view of the olfactory mucosa demonstrating the cilia
A zoom-in view of the olfactory mucosa demonstrating the olfactory receptors
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  • A thin layer of watery mucus made by the supporting cells and Bowman’s (olfactory) glands covers the receptor cilia and microvilli. During inhalation, odorants are drawn into this fluid layer, where they dissolve and then bind to the cilia receptors.
Animation of odorants drawn to the fluid layer
Animation of odorants drawn to the fluid layer
Animation of odorants drawn to the fluid layer
Animation of odorants drawn to the fluid layer
Animation of odorants drawn to the fluid layer
Animation of odorants drawn to the fluid layer
Odorants are drawn into the fluid layer.
  • 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.
Impulses are carried by axons
Impulses are carried by axons
Impulses are carried by axons
Impulses are carried by axons
Impulses are carried by axons
Electro-chemical impulses are carried by receptor axons

An Overview of the Olfactory Mucosa:

image descriptionShow/image descriptionHide answers

A zoom-in view of the mucosa with answers hidden
A zoom-in view of the mucosa with answers shown
Test yourself while observing the Olfactory Mucosa
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