Divisions of the nervous system

• Nervous system - to collect, process and respond to information from the environment and to control organs and cells in the body.
• Central nervous system - consists of the brain and spinal cord.
• Brain

  Receives and processes information from the senses eg visual cortex processes visual information

  Centre of conscious awareness

  Higher mental functions

  Generates emotion and thoughts

  Initiates responses

  Stores memories
• Spinal cord

  Conducts signals to and from the brain

  Connects nerves to the PNS

  Controls reflex actions
• Autonomic nervous system (ANS) - controls involuntary activities such as heart rate, breathing etc. It is divided into two branches; sympathetic and parasympathetic.
• Autonomic nervous system -

  Involuntary responses for vital functions eg heart rate

  Controls smooth and cardiac muscles and glands

  ANS control centres are in the brain stem
• Somatic nervous system -

  Responsible for voluntary movement such as walking

  Transmits information from the brain to control skeletal muscles

  SNS carries commands from the motor cortex

  Connects the CNS and the senses and integrates the brain with the outside world
• ANS -

  Sympathetic branch - fight or flight

  Parasympathetic branch - restore body to homeostasis