Response and Regulation

• Motor neurone


  Carries impulses from the CNS to effectors (muscles and glands)
• Relay neurone


  Carries impulses from sensory neurones to motor neurones in the CNS
• Sensory neurone


  Carries impulses from receptors (sense organs) to relay neurones in the CNS
• Sense organs


  A group of receptor cells that detect specific stimuli and send information to the CNS along neurones e.g. the eye
• Nervous system


  Controls movement by sending electrical signals (nerve impulses) along a network of specialised nerve cells known as neurones to react to environmental or internal changes.
• Stimulus


  A change in the environment, triggering a response from an organism e.g. temperature
• Reflex arc pathway


  Remember: SRSRMER

  Stimulus > receptor > sensory neurone > relay neurone > motor neurone > effector > response
• Reflex arc and its requirements 


  The nerve pathway involved in a reflex action. It requires:

  • Stimulus
  • Receptor
  • Coordinator
  • Effector
  • Response
• What is the nervous system made up of?


  The brain and spinal cord (CNS) and specialised nerves that carry information as impulses in and out of the CNS.
• Central nervous system


  Made up of brain and spinal cord
• Synapse


  A small gap between neurones across which a nerve impulse is transmitted via neurotransmitters.
• Label the diagram of the eye

  a - lens

  b - iris

  c - pupil

  d - cornea

  e - sclera

  f - blind spot

  g - optic nerve

  h - choroid

  i - retina