reflexes

• reflexes are rapid, automatic responses to certain stimuli that don't involve the conscious part of the brain
• the reflex arc is the pathway of the nervous system from the sensory neurone to the effector
• the neurones in reflex arc go through the spinal cord or through an unconscious part of the brain
• when a stimulus is detected by receptors, impulses are sent along a sensory neurone to the CNS
• when an impulse reaches a synapse between a sensory neurone and a relay neurone, they trigger chemicals to be released. these chemicals cause impulses to be sent along the relay neurone.
• when an electrical impulse reached a synapse between a relay neurone and a motor neurone, chemicals are released, causing a chemical impulse to be sent along the motor neurone