the nervous system

• the nervous system is a specialised network of cells called nerves and it is based on electrical signals. Its main functions are collecting and processing information in the environment and coordinating organs and other cells in the body
• Structure of central nervous system:

  • brain- divided into 2 hemispheres and has many layers/areas
  • spinal cord- an extension of the brain
• functions of central nervous system are:

  • brain- central of conscious awareness and distinguishes our higher mental functions form those of animals
  • spinal cord- responsible for reflex actions, passes messages to and from the brain and connects nerves to peripheral nervous system
• structure and function of peripheral nervous system:

  • autonomic nervous system- governs vital functions in the body such as breathing, heart rate and digestion
  • somatic nervous system- governs muscle movement and receives information from sensory receptors
• structure and function of autonomic nervous system:

  • sympathetic nervous system- increases heart rate and breathing rate, dilate pupils, decreases saliva production and digestion
  • parasympathetic nervous system- decreases heart rate and breathing, constricts pupils, increases saliva production and digestion