APA Dictionary of Psychology

the senses receptive to chemical stimulation (i.e., through contact with chemical molecules or electrolytes), particularly the senses of smell and taste. Airborne molecules are inhaled and dissolved in the mucous membrane of the olfactory epithelium to confer odors. Molecules dissolved in liquids are delivered to the taste cells on the tongue, soft palate, larynx, and pharynx to confer tastes.