Nervous System

• What is the nervous system?

  A complex network of nerve cells that carry messages to and from the brain and spinal cord to different parts of the body
• What are the 2 parts of the Nervous System?

  1. Central Nervous System
  2. Peripheral Nervous System
• What is the Central Nervous System?

  • Consists of the Brain and Spinal Cord
  • Main control system for life functions and conscious physiological processes
• The Brain

  • Centre of all conscious awareness
  • It is responsible for perception, motor control, regulating bodily processes and maintaining homeostasis
• Spinal Cord

  • Connects the brain with the Peripheral Nervous System
  • Passes messages to and from the brain
  • Responsible for some reflex actions
• What is the Peripheral Nervous System


  Sends information to the CNS from the outside world and transmits messages from the CNS to the muscles and glands in the body
• What are the 2 parts of the Peripheral Nervous System?

  1. Autonomic Nervous System
  2. Somatic Nervous System
• Somatic Nervous System

  • Responsible for conscious perception and voluntary movement
  • Has sensory neurons - receives sensory information from the outside world to the brain
  • Motor neurons - Somatic NS sends signals to the muscles (motor neurons) to bring about action
• Autonomic Nervous System

  • Responsible for involuntary control over the body
  • Governs vital functions such as breathing, heart rate and digestion
  • Has no sensory but only motor neurons to bring about action
• What 2 parts does the Autonomic Nervous System consist of?

  1. Sympathetic Nervous System
  2. Parasympathetic Nervous System
• Sympathetic Nervous System

  • Gets you ready for emergencies
  • Is involved in fight or flight response
• Parasympathetic Nervous System

  • Restores natural order leaving us back in a normal state
  • Also known as the rest and digest response
• Parasympathetic characteristics

  1. Eyes - Pupils constrict
  2. Salivary Glands - Stimulates salivation
  3. Heart - Slows heartbeat
  4. Lungs - Constrict bronchi
  5. Stomach - Stimulates digestion
  6. Bladder - Contracts bladder
• Sympathetic Characteristics

  1. Eyes - Pupils dilate
  2. Salivary Glands - Inhibit salivation
  3. Heart - Accelerates heartbeat
  4. Lungs - Dilate bronchi
  5. Stomach - Inhibits digestion
  6. Bladder - Relaxes bladder