Your professor is about to "Geek-Out" on everybody (some eustress for me)...
Here is the original article written by Hans Selye (1950) on the General Adaptation Syndrome (G.A.S.)
Click Here for G.A.S. original article
I had no idea (until I put this page together) that this article was readily available on the web. If you ever hear a researcher talking about a "classic article", well this article is one of them.
The General Adaptation Syndrome is a theory put together by Hans Selye which talks about how Stress can affect the body in three separate stages. Here is a good descriptor of what the three stages are: Click Here for G.A.S. stages
Many of us stay within the Alarm stage during the semester. In this stage, our body reacts to stress using the "flight or flight" response (great video...): Click Here for Fight or Flight response In the video, the speaker talks about ATP. We will go over ATP later this semester, but just realize that ATP is the energy we need to make our muscles move.
The hypothalamus in the brain, communicates with the rest of the body through the Autonomic Nervous System (parasympathetic nervous system) ("Glossary"), which controls such involuntary body functions as breathing, blood pressure, heartbeat, and the dilation or constriction of key blood vessels and small airways in the lungs called bronchioles. The Sympathetic Nervous System ("Glossary") functions like a gas pedal in a car. It triggers the fight-or-flight response, providing the body with a burst of energy so that it can respond to perceived dangers. The Parasympathetic Nervous System ("Glossary") acts like a brake. It promotes the "rest and digest" response that calms the body down after the danger has passed. (http://www.health.harvard.edu/newsletters/Harvard_Mental_Health_Letter/2011/March/understanding-the-stress-response)
During Fight or Flight, your heart rate and blood pressure increase, you sweat more, breathing rate increases (all of these mentioned affects are what happens to your body when you exercise!), stomach acid is released, and your brain releases endorphins just in case the stressor that caused the "fight or flight" response brings on pain. After the initial response to stress, your body will keep releasing hormones if you are still worried about that given stressor. The system that releases the hormones is called the endocrine system ("Glossary") and is further explained in this video (watch from 0:00 to 1:00 and again from 5:40-6:40):
This continual stress response ("Glossary") can lead a person to go through the subsequent stages of the General Adaptation Syndrome.
As we mentioned before in class, there are actually two types of stressors ("Glossary") that can bring on the fight or flight reaction: Distressors and Eustressors.
For information on the differences between these two, go here: Click Here for disstress vs eustress article. Disstressors stay with us for a longer period of time (we tend to dwell on them... not so good for our health... more on this later in the semester when talking about Heart Disease). Eustressors keep us motivated and excited about life.