2.74 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses

2.74 •1.receptors in a sense organ detect a stimulus, they send electrical impulses along sensory neurones to the CNS

         2.the CNS then sends electrical impulses to an effector along a motor neurone 

                      •the effector responds

        •the job of the CNS is to coordinate the response 

                  •coordinated responses always need a stimulus, a receptor and an effector 

                             •because neurones transmit information by electrical impulses, the nervous system is able to carry out rapid responses