Autonomic Nervous System

• The autonomic nervous system is concerned with maintaining a stable

  internal environment by playing a part in homeostasis
• The autonomic nervous system consists of two divisions, sympathetic and parasympathetic.
• On stimulation the sympathetic system arouses the body in preparation for action and expenditure of energy
• The hormone adrenalin helps to sustain the arousal effect until the emergency is dealt with
• Taking a defensive stand or running away both require vast amounts of extra energy - This is supplied by the increased blood flow to the muscles
• When the excitement is over the parasympathetic system takes over for a brief spell calming the body down, returning it to normal.

  
  

  • Heart rate and blood pressure drop

  • Peristalsis in intestine increases

  • Parasympathetic nerves help body to

  – Conserve resources

  – Store energy