an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulation | an organ (a gland or muscle) that becomes active in response to nerve impulses |
a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response | a nerve fiber that terminates on a muscle or gland and stimulates contraction or secretion |
| one who brings about a result or event; one who accomplishes a purpose |