reflex arc

• components of a reflex arc:

  stimulus

  receptor

  neurones

  effector

  response
• stimulus - any change in the environment to which the body needs to respond. detected by a receptor
• receptor - all over the body. detect the change in the environment. initiate a signal process in the body. signal is picked up by a neurone (nerve cell)
• sensory neurone - carries signal in form of electrical impulse to the CNS
• relay neurone - carries impulses from sensory neurones to motor neurones. in the CNS
• motor neurone - carries impulses from the CNS to the effector
• effector - muscle or gland that responds to a stimulus and produces a response
• response - any action that helps the organism avoid the harmful situation
• response

  • any action that helps the organism avoid the harmful situation
• effector

  • a muscle or gland that responds to a stimulus
  • produces a response
• motor neurone

  • carries impulses from the CNS to the effector