receptor - an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulationorgan - a fully differentiated structural and functional unit in an animal that is specialized for some particular function exteroceptor - any receptor that responds to stimuli outside the body pineal eye, third eye - a sensory structure capable of light reception located on the dorsal side of the diencephalon in various reptiles chemoreceptor - a sensory receptor that responds to chemical stimuli ear - the sense organ for hearing and equilibrium organ of hearing - the part of the ear that is responsible for sensations of sound semicircular canal - one of three tube loops filled with fluid and in planes nearly at right angles with one another; concerned with equilibrium stretch receptor - a receptor in a muscle that responds to stretching of the muscle tissue papilla - a small nipple-shaped protuberance concerned with taste, touch, or smell; "the papillae of the tongue" effector - an organ (a gland or muscle) that becomes active in response to nerve impulses |