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The Definition Of Epinephrine


Updated June 30, 2012

The Definition Of Epinephrine
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Definition: Also known as adrenalin, epinephrine is a naturally occurring hormone. During the fight-or-flight response response, the adrenal gland releases epinephrine into the blood stream, along with other hormones like cortisol, signaling the heart to pump harder, increasing blood pressure, opening airways in the lungs, narrowing blood vessels in the skin and intestine to increase blood flow to major muscle groups, and performing other functions to enable the body to fight or run when encountering a perceived threat.

The term perceived threat makes an important distinction and brings up a critical point to remember: as in the case of chronic stress, the body's stress response is repeatedly triggered on a daily basis in response to actual physical and psychological threats as well as perceived psychological threats. As a result, the body can become exhausted, and the overabundance of epinephrine and cortisol, as well as other aspects of the body's stress response can become maladaptive, resulting in lowered immunity and other health problems. (Read this article for more on the effects of stress.)

Another important thing to remember about epinephrine and the body's stress response is that it can be triggered in response to negative stress as well as excitement or eustress. While eustress, or 'positive stress' can help maintain vitality, it's still important to maintain balance in how much your stress response is triggered, and to avoid too much total stress.

If you would like more resources on stress management, you can sign up for this site's Stress Management Newsletter, or use this quick self assessment tool to find stress relievers that would work best for your personality and lifestyle.

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Also Known As: adrenaline, adrenalin
Alternate Spellings: epinephrin

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