What are some of the physiological responses the body experiences when a person experiences fear? How might these "fight or flight" physiological responses be useful for survival?

     There are two stages of the fight or flight response, which are short term fight or flight response and long-term fight or flight response. Short-term response is triggered in response to short-term threats and long-term fight or flight response is triggered hormonally (Stress Management for Health Course, n.d.). Some physiological and biochemical responses to flight or fight are the increase in blood flow, blood pressure, blood sugar and fats increase, blood clots quicker, red blood cells increase, breathing rate increases, muscles tense, digestion slows, pupils dilate, hearing becomes sharper, perspiration increases, and one feels an increase in fear and anxiety (Stress Management for Health Course, n.d.). Fight or flight responses are useful for survival because they give an individual extra speed and strength, which allows one to fight or run away. 

Reference

Stress Management for Health Course. (n.d.). Retrieved from http://stresscourse.tripod.com/id11.html