the nervous system

• Key features

  The nervous system is a specialised network of cells and our primary communication system. It is based on electrical signals whereas the endocrine system is based on hormones.

  The nervous system has two main functions :

  1. collect, process, and respond to information in the environment
  2. to co-ordinate the working of different organs and cells in the body
• Structure and functions

  CNS is made up of the brain and spinal cord

  Brain - centre of conscious awareness, outer layer of the brain is the cerebral cortex, is highly developed in human brains and is what distinguishes our higher mental functions from those of animals. The brain is divided into two hemispheres

  Spinal cord - the spinal cord is a extension of the brain and is responsible for reflex actions. It passes messages to and from the brain and connects nerves to the PNS
• Structure

  1. human nervous system
  2. peripheral nervous system
  3. Central nervous system
  4. Autonomic nervous system
  5. somatic nervous system
  6. brain
  7. spinal cord
  8. sympathetic nervous system
  9. parasympathetic nervous system

  
• peripheral nervous system

  The PNS transmit messages via millions of neurons to and from the nervous system

  The PNS is further subdivided into :

  1. autonomic nervous system governs vital functions in the body like breathing, heart rate etc
  2. somatic nervous system governs muscle movement and receives information from sensory receptors