Divisions of the Nervous System

• What are the two main parts of the nervous system?

  Central nervous system and peripheral nervous system
• What is the primary function of the human nervous system?

  To collect, process information, and take action
• How does the nervous system transmit messages?

  By transmitting electrochemical messages
• What does the central nervous system consist of?

  Brain and spinal cord
• What role does the spinal cord play in the CNS?

  It receives and transmits information to and from the brain
• What are sensory or afferent neurons responsible for?

  Delivering information to the CNS
• What do motor or efferent neurons do?

  Transmit information away from the CNS
• What does the somatic nervous system control?

  Skeletal muscles
• How is the somatic nervous system characterized?

  It is a voluntary system under conscious control
• What does the autonomic nervous system control?

  Internal organs and glands
• How is the autonomic nervous system characterized?

  It is an involuntary system not under conscious control
• What are the two branches of the autonomic nervous system?

  Sympathetic and parasympathetic
• What is the function of the sympathetic branch?

  Activates the fight-or-flight response
• What neurotransmitter is released by the sympathetic branch?

  Noradrenaline
• What happens during the fight-or-flight response?

  Heart rate and breathing increase, digestion stops
• What is the function of the parasympathetic branch?

  Decreases bodily activities and promotes rest
• What neurotransmitter is released by the parasympathetic branch?

  Acetylcholine
• What is homeostasis?

  Maintaining a balanced internal environment
• How many nerve cells are estimated to be in the gut?

  About 100 million
• How does the number of nerve cells in the gut compare to a cat's brain?

  Similar in number
• What is the significance of the nervous system in the body?

  It coordinates actions and responses to stimuli
• What are the main functions of the nervous system?

  • Collects information from the environment
  • Processes this information
  • Directs bodily organs and muscles
  • Transmits electrochemical messages
• What are the differences between the sympathetic and parasympathetic branches of the autonomic nervous system?

  Sympathetic:

  • Activates fight-or-flight response
  • Increases heart rate and breathing

  
  

  Parasympathetic:

  • Promotes rest and digestion
  • Decreases heart rate and breathing