the nervous system

• The nervous system

  Specialised network of cells in the human body and our primary internal communication system.

  Based on electrical and chemical signals
• Functions of the nervous system

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

  • Central nervous system
  • Peripheral nervous system
• The central nervous system

  • made up of the brain and the spinal cord
  • brain = centre of all conscious awareness.

  brain's outer layer = cerebral cortex (3mm thick)

  the brain is highly developed in humans - higher mental functions

  two hemispheres

  • spinal cord is an extension of the brain

  passes messages to and from the brain and connects nerves to PNS

  responsible for reflex actions
• The peripheral nervous system

  transmits messages via neurons to and from the central nervous system

  • autonomic nervous system - governs vital functions in the body (breathing, heart rate, digestion)
  • somatic nervous system - governs muscle movement and receives information from sensory receptors