5.2-human nervous system

• What is the primary function of the nervous system?

  To react and coordinate responses
• What sequence describes how the nervous system works?

  Stimulus → receptor → coordinator → effector → response
• How is a stimulus converted into a response?

  It becomes an electrical impulse via receptors
• What happens to the electrical impulse after it is generated?

  It travels along sensory neurones to the CNS
• What role does the CNS play in response coordination?

  It coordinates an appropriate response
• How does the motor neurone contribute to a response?

  It sends impulses to the effector
• What is a reflex action?

  An automatic and rapid response
• Why are reflex actions important?

  They prevent harm to the body
• What is the difference between a reflex pathway and a conscious pathway?

  Reflex pathways use relay neurones in the spinal cord
• Describe how a reflex action occurs via a reflex arc.

  • Stimulus detected by receptor
  • Impulse travels along sensory neurone to spinal cord
  • Chemical diffuses at synapse to relay neurone
  • Impulse travels along relay neurone
  • Same process at synapse to motor neurone
  • Effector carries out response