Divisions of the Nervous System

• What is the Human Nervous System?

  A specialised network of cells in the human body that is our primary internal communication system - based on chemical and electrical signals.
• What are the functions of the Human Nervous System

  • collecting information
• What are the functions of the Human Nervous System

  1. Collecting information in the environment
  2. Processing information in the environment
  3. Responding to information in the environment
  4. Co-ordinating the working of different organs and cells in the body
• What are the two components of the Human Nervous System

  • Peripheral Nervous System - Transmits messages via millions of neurons to and from the CNS
  • Central Nervous System - Consists of the brain and the spinal cord and is the origin of all complex commands and decisions
• What Components make up the CNS

  • Brain - centre of all conscious awareness
  • Spinal Cord - Passes messages to and from the brain and connects the nerves to the PNS(An extension of the brain)
• What else is the spinal cord responsible for

  Reflex actions
• Components of the PNS

  • Autonomic Nervous System (operates involuntarily = automatic) - Transmits information to and from internal bodily organs and governs their basic functions e.g. breathing
  • Somatic Nervous System - Transmits info from receptor cells in the sense organs to the CNS + receives info from the CNS that directs muscles to act
• Components of the Autonomic Nervous System

  • Sympathetic Nervous System - Controls the fight-or-flight response => can lead to physiological changes like increased heart rate
• Components of the ANS

  • Controls the fight-or-flight response -> can lead to physiological changes like increased heart rate
  • Parasympathetic Nervous System - Aims to return the body to a state of calm i.e. reduced heart rate