nervous system

• Purpose:

  • complex network of nerve and associated cells
  • carry messages to and from CNS to other parts of the body
  • ensures each organ systems (cardiovascular, gastro-intestinal, immune) can communicate with one another
  • receives, interprets and responds to information
• Overall functions:

  • senses stimuli - receptor
  • Reaction to stimuli (internal and external) - effector
  • Co-ordination of various activities - CNS
  • Controlling voluntary activity - CNS
  • Regulating involuntary activities - CNS
• How CNS is protected:

  • cranium - protects brain against mechanical injury, made up of 8 bones held by immovable joints called sutures
  • vertebral column - 33 vertebrae that surround the spinal cord, discs made from white fibrous cartilage absorbs shock prevents jarring
  • Meninges - 3 membranes the surround the brain and spinal cord, in between the second and 3rd membrane CSF, a cushion for shock and damage