How do bodies respond to a stimulus?

There are multiple types of stimuli bodies can receive. These include light to the eye or a touch to the skin. I am going to use the example of a touch to the hand. The stimulus, a touch, is detected by receptor cells in the skin. This causes electrical impulses to be generated and travel along sensory neurons to the central nervous system or CNS. The CNS is made up of the spinal cord and brain. It coordinates, or organises, the response. It contains relay neurons which pass the electrical impulse to the correct motor neurons. These carry the impulse to effector cells which produce a response to the stimulus. In this case the effector would be a muscle in the hand, and the impulse would cause the muscle to contract and move the hand.