Biology

• What is the Central Nervous System made up of?

  The brain and the spinal cord
• What does a receptor detect?

  A stimulus
• Which receptors detect light?

  Eyes
• What is a reflex response?

  An automatic and rapid response
• What is the purpose of a reflex response?

  To protect the body from harm
• What are the stages of the reflex arc?

  • Stimulus
  • Receptor
  • Sensory neurone
  • Relay neurone
  • Motor neurone
  • Effector
  • Response
• What is an effector?

  Muscles or glands that respond
• What happens at a synapse?

  Chemicals diffuse to pass on impulses
• What does the brain control?

  Complex behaviour
• What is accommodation in the context of vision?

  Changing the lens shape to focus
• What is the cerebral cortex responsible for?

  Higher-order processes
• What is the function of the cerebellum?

  Coordinated muscle control and balance
• What does the medulla control?

  Unconscious activities like heart rate
• How does information from receptors travel?

  As electrical impulses to the CNS
• What does the central nervous system coordinate?

  The response of effectors
• What does the nervous system enable humans to do?

  React to surroundings and coordinate behaviour
• What happens to circular muscles in dim light?

  They relax
• What happens to radial muscles in bright light?

  They relax
• Why must light be focused on the retina?

  To see a clear image
• How do spectacle lenses help those who are short or long sighted?

  They refract light rays to focus on the retina
• What type of lens is used for short sightedness?

  Concave lens
• What causes myopia?

  An eyeball that is too long
• What causes hyperopia?

  An eyeball that is too short
• What type of lens is used for long sightedness?

  Convex lens
• What happens during accommodation for a near object?

  Ciliary muscles contract and lens thickens
• What happens during accommodation for a far object?

  Ciliary muscles relax and lens thins
• What receptors are contained in the eye?

  Receptors sensitive to light intensity and colour
• What is the eye classified as?

  A sense organ