"fight-or-flight" response refers to the body's natural reaction
to an emergency. The body systems which are useful for facing
a threat ("fight") or fleeing danger ("flight") are stimulated:
blood flow is increased to the muscles, heart rate increases,
respiration increases, and blood pressure increases. As a
tradeoff, energy is decreased to other ongoing body functions
including digestion, immune
system response, ovulation, and so on.
In the short term, the fight-or-flight response
is a natural and appropriate response to stress
or threat. In fact, it is generally believed that a certain
amount of stress is necessary for physical well-being. However,
prolonged stress can damage body function, leading to high
blood pressure, gastrointestinal and digestive problems, decreased
immune system response, and even brain damage.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain