Also found in: Dictionary, Thesaurus, Medical.
any one of a large group of specialized sensory structures that perceive stimulation arising from the external environment. Exteroceptors are situated on the surface of the bodies of animals and humans (including the mucous membranes of the nose, mouth, and tongue). Depending on the nature of the stimulus perceived, a distinction is made between mechanoreceptors of the skin (tactile), chemoreceptors (gustatory and olfactory organs), thermoreceptors of the skin, photoreceptors, and receptors of the organs of hearing and equilibrium. Dolphins, bats, and noctuids have receptors sensitive to ultrasound; some fishes are sensitive to electric fields.