1-10. ANATOMY OF OLFACTION
Olfactory sense receptors are located in the nasal epithelium in the superior part
of the nasal cavity on either side of the nasal septum. There are two kinds of cells in
the nasal epithelium: supporting cells and olfactory cells. Supporting cells are shaped
like columns and are located in the mucous membrane lining of the nose. This
membrane is kept moist by the olfactory glands. The olfactory cells lie between the
supporting cells. The free end of each olfactory cell contains six to eight dendrites
called olfactory hairs.
Figure 1-10. Organs of smell.
1-11. PHYSIOLOGY OF OLFACTION
The sensation of smell functions in this manner. We breathe in a gaseous
substance that dissolves in the fluid of the nasal chamber. The fluid stimulates the
olfactory cells in the upper part of the nasal mucosa. Sniffing increases the amount of
gaseous substance, and the odor becomes stronger. The sensory pathway for the
sense of smell is the olfactory nerve. Olfactory cells transmit impulses from the
receptors over the olfactory nerve to the brain.