Smell and taste are two of our five senses that are co-dependent. They contribute substantially to our desire to eat.

The complicated processes of smelling and tasting begin when molecules released by the substances around us stimulate special nerve cells in the nose, mouth, or throat. These cells transmit messages to the brain, where specific smells or tastes are identified. Olfactory cells are stimulated by the odors around us. These nerve cells are found in a tiny patch of tissue high up in the nose, and they connect directly to the brain.

Gustatory cells react to food or drink mixed with saliva and are clustered in the taste buds of the mouth and throat.

The common chemical sense is the system of thousands of free nerve endings - especially on the moist surfaces of the eyes, nose, mouth, and throat – that identifies sensations like the sting of ammonia, the coolness of menthol, and the "heat" of chili peppers.

We can commonly identify four basic taste sensations: sweet, sour, bitter, salty. Certain combinations of these tastes - along with texture, temperature, odor, and the sensations from the common chemical sense - produce a flavor. It is flavor that lets us know what we’re eating.

Many flavors are recognized mainly through the sense of smell. If you hold your nose while eating chocolate, for example, you will have trouble identifying the chocolate flavor, even though you can distinguish the food's sweetness or bitterness.

A person who wishes to fully savor a delicious flavor will exhale through his nose after each swallow.
Taste and smell cells are the only cells in the nervous system that are replaced when they become old or damaged.