the nervous system

• the nervous system…


  specialised network of cells in the human body
• what are the roles of the nervous system?

  • to collect, process and respond to information in the environment
  • to co-ordinate the working of different organs and cells in the body
• what are the two sections that the nervous system is split up into?

  1. the central nervous system
  2. the peripheral nervous system
• what are the two body parts that make up the CNS?

  brain and spinal cord
• the brain…

  centre of all conscious awareness - separated into hemispheres and is highly developed in humans
• the spinal cord…

  acts as an extension of the brain - passes message to and from the brain, and connect nerves to the peripheral nervous system
• the peripheral nervous system…

  transmits messages via neurons (nerve cells) to and from the CNS
• what is the PNS divided into?

  somatic and autonomic nervous systems
• the somatic nervous system…


  is responsible for carrying sensory and motor information to and from the spinal cord
• the autonomic nervous system…

  governs vital functions in the body such as; breathing, heart rate, digestion, sexual arousal and stress responses
• what is the autonomic nervous system further divided into?

  parasympathetic and sympathetic nervous system
• what type of relationship does the sympathetic and parasympathetic nervous systems have?

  antagonistic (opposing/working against each other)
• which nervous system is responsible for ”fight or flight”?

  sympathetic
• what happens to the body when it’s in a state of fight or flight?

  heart rate increases

  digestion slows

  eyes dilate

  inhibits saliva production
• what does the body do to relax?

  increases saliva production

  increases digestion

  decreases heart rate

  constricts pupils
• which nervous system allows the body to relax?

  parasympathetic nervous system
• what does the stage of “fight or flight” mean for the human body?

  acts as a mechanism to protect the body against stress or danger

  sympathetic nervous system controls the necessary bodily changes needed when we need to defend ourselves and escape