Shape: Tall columnar, wide at the top, thin at the base, with many microvilli on the free surface

Location: Located in the superficial part of the olfactory epithelium, pigment granules are often visible in the cytoplasm

Role: Supporting cells and separating olfactory cells, equivalent to glial cells

Ciliated cells: the most numerous, columnar, with dense cilia on the free surface. The cilia swing rapidly toward the pharynx, pushing mucus, adhered dust, bacteria, etc. to the pharynx and coughing them out to purify the inhaled air.

Goblet cells: more numerous, with the same shape as intestinal mucosal goblet cells. The secreted mucin and mixed gonad secretions form a mucus barrier on the epithelial surface, which can adhere to foreign particles in the air and dissolve inhaled toxic gases such as sulfur dioxide.

Brush cells: fewer, columnar, with neatly arranged microvilli on the free surface, shaped like a brush. The function of brush cells has not yet been determined.

Small granule cells: fewer, cone-shaped, regulate contraction of respiratory smooth muscles and secretion of glands

Basal cells: Cone-shaped, located deep in the epithelium. They are stem cells that can proliferate and differentiate into other types of cells in the epithelium. Aged ciliated cells and dorsal cells will continue to fall off

Function: It is the part of the lungs where gas exchange occurs and constitutes the main structure of the lungs.

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