heterologous stimuli

1 definition found

heterologous stimuli - Collaborative International Dictionary of English v.0.48 :

  Stimulus \Stim"u*lus\, n.; pl. Stimuli. [L., for stigmulus,
     akin to L. instigare to stimulate. See Instigare, Stick,
     v. t.]
     1. A goad; hence, something that rouses the mind or spirits;
        an incentive; as, the hope of gain is a powerful stimulus
        to labor and action.
        [1913 Webster]
  
     2. That which excites or produces a temporary increase of
        vital action, either in the whole organism or in any of
        its parts; especially (Physiol.), any substance or agent
        capable of evoking the activity of a nerve or irritable
        muscle, or capable of producing an impression upon a
        sensory organ or more particularly upon its specific end
        organ.
        [1913 Webster]
  
     Note: Of the stimuli applied to the sensory apparatus,
           physiologists distinguish two kinds: (a) Homologous stimuli
           , which act only upon the end organ, and for
           whose action the sense organs are especially adapted,
           as the rods and cones of the retina for the vibrations
           of the either. (b) Heterologous stimuli, which are
           mechanical, chemical, electrical, etc., and act upon
           the nervous elements of the sensory apparatus along
           their entire course, producing, for example, the flash
           of light beheld when the eye is struck. --Landois &
           Stirling.
           [1913 Webster]