Olfactory epithelium

Olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell. In humans, it measures about 1 square centimeter (on each nasal septum) and lies on the roof of the nasal cavity about 7 cm above and behind the nostrils. The olfactory epithelium is the part of the olfactory system directly responsible for detecting odors.

Structure

The olfactory epithelium consists of olfactory receptor cells, supporting cells, basal cells, and Bowman's glands. The olfactory receptor cells are neurons which contain olfactory receptors, proteins responsible for detecting odor molecules. The supporting (sustentacular) cells function to provide metabolic and physical support for the olfactory receptor neurons. Basal cells are stem cells capable of division and differentiation into either supporting cells or olfactory receptor neurons. Bowman's glands are serous glands in the lamina propria, whose secretions trap and dissolve odoriferous substances.

Function

The primary function of the olfactory epithelium is the detection of odorants. Odorants are volatile chemical compounds that are carried in the air. The process of odor detection is complex and involves the binding of odorant molecules to olfactory receptors on the cilia of the olfactory receptor neurons. This binding causes an electrical response that is transmitted to the brain for interpretation.

Clinical significance

Damage to the olfactory epithelium can result in an inability to smell (anosmia), a decreased ability to smell (hyposmia), a distorted sense of smell (dysosmia), or a phantom smell (phantosmia). Causes of damage can include infection, nasal obstruction, and neurodegenerative diseases.

See also

• Olfaction
• Olfactory bulb
• Olfactory nerve
• Olfactory receptor

External links

• Olfactory Epithelium: Cells, Clinical Disorders, and Insights from an Adult Stem Cell Niche

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  Embryonic olfactory epithelium
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  Olfactory Sensory Neurons innervating Olfactory Glomeruli
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  Riechschleimhaut
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  Olfactory epithelium pig