Stress Response: Fight or Flight

Alarm phase

  1. The heart beat increases to pump blood to all of the necessary tissues with greater speed
  2. As the heart rate increases so does blood pressure
  3. Breathing becomes rapid and shallow
  4. Adrenaline hormones are released from the adrenal gland
  5. Liver releases stored sugar to meet the increased need for energy
  6. Pupils dilate and senses become heightened
  7. Muscles tense for movement
  8. Blood flow is restricted from the digestive tract
  9. Blood flow is increased to the brain and major muscles
  10. Blood flow is constricted from the extremities
  11. Body perspires to cool itself

Adaptation and resistance phase

The adrenals now release corticosteroids that help provide energy and the specific circulatory changes (glucocorticoids help to keep blood sugar stable and mineral corticoids help us retain sodium which helps our body maintain an elevated blood pressure).

Exhaustion Phase

With the unabated production of corticosteroids, organs and organ systems become weak and may cease to function.

Did you know?

70-80% of all visits to the doctor are related to stress
• Stress contributes to 50% of all illnesses in the US
• The cost of job stress in the US is estimated at over 200 billion
dollars annually, including the cost of absenteeism, lost
productivity and insurance claims