The olfactory mucosa is located in the upper region of the nasal cavity and is made up of the olfactory epithelium and the underlying lamina propria, connective tissue containing fibroblasts, blood vessels, Bowman's glands and bundles of fine axons from the olfactory neurons.
The mucus protects the olfactory epithelium and allows odors to dissolve so that they can be detected by olfactory receptor neurons. Electron microscopy studies show that Bowman's glands contain cells with large secretory vesicles. The exact composition of the secretions from Bowman's glands is unclear, but there is evidence that Bowman's glands do not produce odorant binding protein.
In vertebrates, the olfactory epithelium consists of a three basic cell types: bipolar olfactory receptor neurons; sustentacular cells, a type of supporting cell; and basal cells, the stem cells that continuously give rise to new olfactory receptor neurons and sustentacular cells.
Cells in the olfactory mucosa have been shown to have a degree of plasticity, and hold potential for therapeutic applications.
Such cells have been used in clinical trials for adult stem cell therapeutic treatments, and successfully harvested for future applications.