1) Interoceptor 2) Receptor 3) Sense organ 4) Sensory receptor 1) Interoceptor 
(from the article `receptor`) ...to which they respond (photoreceptor, chemoreceptor, etc.). More broadly, they are sometimes categorized by the source of their stimuli, ... ...receive signals from outside the organism and are parts of the exteroceptive system. Receptors located inside the body receive signals from ... ...The Integra...