Topic Summaries

The nervous system is separated into two divisions: the central nervous system and the peripheral nervous system.

• The central nervous system:
  • The brain: receives and process information from the senses. It contains our conscious awareness, imitates responses, stores memories, and generates emotions and thoughts.
  • The spinal cord: conducts signals to and from the brain. It controls our reflex actions.
• The peripheral nervous system: sends messages to and from the central nervous system via neurons and is separated into two parts: the autonomic nervous system and the somatic nervous system.
  • The autonomic nervous system: involuntary responses. This system only has motor pathways and doesn’t directly control effectors. It’s separated into the sympathetic branch and the parasympathetic branch:
    • Sympathetic branch: the fight or flight response that prepares the body to confront a threat when stressed.
    • Sympathetic branch: restores and conserves the body’s energy when relaxed or after a threat has passed.
  • The somatic nervous system: voluntary movements. This system is made up of motor and sensory pathways, and it can control effectors directly.