How does the fight or flight reaction work? (I think its called acute stress response?)

Question: How does the fight or flight reaction work? (I think its called acute stress response?)
- Keywords:
  hormone
Asked by u11keenm to Derek, Elaine, Heather, Keith on 27 Jun 2013.
- Heather Eyre answered on 27 Jun 2013:
  
  When your body thinks you are in danger you go in to a stress state – fight or flight.
  
  The response is initially set off in the subconscious brain, but the end result is the release of adrenaline by the adrenal glands which are near the kidneys.
  
  Te release of adrenaline has lots of different effects on the body:
  
  Your heart rate and breathing rate increase: taking more oxygen and fuel to muscles so you can run faster or fight harder.
  The blood flow to your digestive system is reduced to allow more blood to the muscles.
  Energy stores start releasing their energy
  The pupils dilate to let in more light
- Keith Siew answered on 27 Jun 2013:
  
  Can’t add much more to this! Great answer from Heather

Question: How does the fight or flight reaction work? (I think its called acute stress response?)