Reflex action

• A reflection action is a rapid automatic response to a stimilus. They happen very quickly because they don't involve the conscious part of the brain
• Effector


  The part of the body that responds to a stimulus, usually a muscle
• The neurones in a reflex arc go through the spinal cord
• The neurones in reflex arcs can also go through an unconscious part of the brain
• 
1. Receptor detects stimulus

  2. Receptor sends electrical impulse through sensory neurone
• 3.Impulse reaches synapse

  4. Neurotransmitters cross synapse and generate impulse in relay neurone
• 5. Impulse reaches another synapse and more neurotransmitters released

  6. Impulse generated in motor neurone
• 7. Motor neurone carries impulse to effector (muscle) 8. Muscle contracts