This creates an automatic and rapid response to a stimulus, which minimises any damage to the body from potentially harmful conditions, such as touching something hot.
Receptor in the skin detects a stimulus (the change in temperature).
Sensory neurone sends electrical impulses to relay neurone, which are located in the spinal cord. They connect sensory neurones to motor neurones.
Motor neurone sends electrical impulses to an effector.
Effector produces a response (muscle contracts to move hand away).
Where two neurones meet there is a small gap, a synapse.
An electrical impulse travels along the first axon. - synapse
This triggers the nerve-ending of a neurone to release chemical messengers called neuro transmitters - synapse
These chemicals diffuse across the synapse (the gap) and bind with receptor molecules on the membrane of the second neurone. -synapse
This stimulates the second neurone to transmit the electrical impulse.
