Divisions of the Nervous System

• The nervous system - a network of cells in the human body (the body's internal communication system).
• The function of the nervous system - to collect, process and respond to information from the environment, and to control organs and cells.
• The nervous system is divided into the central nervous system and the peripheral nervous system (which sends messages to and from the central nervous system via neurons).
• The central nervous system is made up of two parts - the brain and the spinal cord.
• Function of the brain:

  > Receive and process information from senses

  > Centre of conscious awareness

  > Responsible for higher mental functions (take knowledge and use it to create new ideas and concepts)

  > Generate thoughts and emotions

  > Store memories
• Function of the spinal cord:

  > Conduct signals to and from the brain

  > Connects nerves to the peripheral nervous system

  > Controls reflex actions
• The peripheral nervous system is divided into the autonomic nervous system and the somatic nervous system. The autonomic nervous system is further divided into the sympathetic and the parasympathetic branch.
• Autonomic Nervous System:

  > Responsible for involuntary responses e.g. breathing, digestion

  > Controls smooth and cardiac muscles and glands

  > The control centres are in the brain stem
• Somatic Nervous System:

  > Responsible for voluntary movements

  > Transmits information from brain to skeletal muscles

  > Carries commands from (controlled by) motor cortex

  > Connects the CNS and the senses to integrate brain with outside world
• The sympathetic branch is responsible for the fight or flight response.
• The parasympathetic branch conserves and restores body energy when relaxed.