Nervous System

• What is the nervous system made up of?

  Neurones (nerve cells)
• What do sensory receptors detect?

  Changes in the environment (stimuli)
• What do receptors in your eyes detect?

  Light
• What do receptors in your skin detect?

  Touch (pressure) and temperature change
• How is information sent to the CNS?

  As nervous (electrical) impulses along sensory neurones
• What does the CNS consist of?

  The brain and spinal cord
• What is the role of the CNS?

  To coordinate the response to stimuli
• What does the CNS send information to?

  An effector (muscle or gland)
• What happens when the effector receives information?

  It responds accordingly (e.g., muscle contracts)
• How are electrical impulses passed along a neurone?

  Along the axon
• What do branched endings (dendrites) of neurones do?

  Connect with lots of other neurones
• What is the function of the myelin sheath?

  Acts as an electrical insulator, speeding up impulses
• Why are neurones long?

  To speed up the impulse transmission
• What is the connection between two neurones called?

  A synapse
• What happens at a synapse?

  The electrical impulse triggers the release of transmitter chemicals
• What do transmitter chemicals do at the synapse?

  Bind to receptor molecules in the next neurone
• What are reflex actions?

  Automatic responses done without thinking
• What is a reflex arc?

  The passage of information from receptor to effector
• Is the conscious brain involved in a reflex arc?

  No, it is not involved
• What connects sensory neurones to motor neurones in a reflex arc?

  A relay neurone
• What is the role of reflex actions?

  Often have a protective role
• What is the first step in a reflex action when a bee stings?

  Stimulation of pain receptor
• What does the cerebrum control?

  Consciousness, intelligence, memory, and language
• What is the function of the hypothalamus?

  Maintains body temperature and produces hormones
• What does the medulla control?

  Unconscious activities like breathing
• What is the role of the cerebellum?

  Responsible for muscle coordination
• Why is studying the brain important?

  To understand brain functions and treat damage
• How do scientists learn about brain function?

  Through case studies of individuals with abnormalities
• What can the effects of brain damage tell scientists?

  About the functions of the damaged brain area
• What technology do scientists use to study brain activity?

  fMRI scanners
• What is a challenge in studying brain function?

  Ethical issues with severely brain-damaged patients
• What is a limitation of using case studies?

  Interpreting results can be problematic
• What can happen during treatment for nervous system problems?

  Permanent damage may occur
• What does the cornea do?

  Refracts (bends) light into the eye
• What does the iris control?

  How much light enters the pupil
• What is the function of the lens?

  Focuses light onto the retina
• What do ciliary muscles do?

  Alter the shape of the lens
• What is the retina covered in?

  Receptors called rods and cones
• What do rods detect?

  Light in dim conditions
• What do cones detect?

  Different colors of light