The Human Nervous System: Function
- The pathway through the nervous system can be summarised as follows:
stimulus → sensory neurone → relay neurone → motor neurone → effector → response
- First, a stimulus is received by a sensory (receptor) neurone
- Most receptors are specialised to detect particular stimuli
- When a receptor is stimulated, it produces electrical impulses
- These impulses then travel along a sensory neurone to the central nervous system (the coordinator is either the brain or the spinal cord)
- In the CNS, the impulses are passed on to a relay neurone
- The relay neurone links to a motor neurone, along which the impulses travel until they reach the effector
- The effector is what carries out the response (the effector may be a muscle or gland)
From stimulus to response: an example of a nerve pathway showing how an electrical impulse travels through sensory, relay and motor neurones
