By: Syed Jafri
Hello! I will be your guide on understanding stress and its affects on YOUR body!
Let's start by understanding WHAT stress is
Stress is an excessive or unknown stimulus that disrupts homeostatic mechanisms
Some examples of stress you might face are:
Sickness or Infections
Low/High Blood Suger
Lack of Sleep
Pressure caused by Exams
Our bodies are designed to tolerate these unusual events, it is in our design to thrive through mechanisms organisms developed such as physiological, metabolic and behavioral responses, known as
The General Adaptation Syndrome (GAS), or popularly a stress response, intended at minimizing the impact of the stressor followed by protection of vital functions until homeostasis can be restored.
Homeostasis is when physiological processes are maintained by keeping a relatively stable equilibrium between interdependent elements
The General Adaption Syndrome model was introduced by scientist Hans Selye in 1936. In his model he suggest there are three phases to the GAS, each showing alleged effects of stress on the body.
First is the ALARM phase
The Second is the RESISTANCE phase
The third is the EXHAUSTION phase
Your body's first reaction to present stress is to recognize if there is danger and prepares to deal with any threat-- the "fight or flight" response".
This response will cause mobilization of energy reserves (releasing glucose from glycogen) and the dominant hormone epinephrine.
The response to the stress causes several characteristics in the ALARM phase to arise...
Increased mental awareness
Increased energy consumption
Mobilization of energy reserves
Circulation changes: -Increased blood flow to skeletal muscles -Decreased blood flow to skin, kidneys, and digestive organs
Reduction in digestion and urine production
During the ALARM phase the main stress hormones cortisol, adrenaline, and noradrenaline, are released to provide instant energy.
If the energy released is not used by physical means then it could have a negative affect on you.
For instance if you produce more adrenaline than needed then theres a chance your blood pressure could surge causing blood vessels to be damaged in the heart and brain
This posses a serious risk of heart attacks and strokes.
With this first phase everything is operating as they should be: due to stress in the environment your body reacts and alarms you with a sudden change in hormones, you are now supplied with enough energy to handle it.
The body then shifts into a second phase focused on resolving and eliminating the source of stress. With homeostasis, balance is being restored and repairment and renewal takes place
The levels of stress hormones produces may return to normal with the cost of lowered defenses and adaptive energy left
In the resistance phase, metabolism is switched to protect vital functions with the cost of less critical processes.
The main task during this phase is to conserve energy processes at the cost of highly specialized functions that that are not relevant to immediate survivale.
The major signaling molecule during resistance phase is cortisol
Cortisol is a very hydrophobic molecule that travels blood bound to cortisol-binding globulin (CBG). It is able to cross the cell membrane through passive diffusion, binding to cortisol receptors within the cytosol.
Cortisol is used to increase blood sugar (while leaving reserve glucose for the brain), repress the immune system, and help in fat, protein, and carbohydrate metabolism
If the stressful stimulus is still present your body will alter by a consistant effort in resistance. However, problems will arise if your body repeats this process too much or with no recovery time.
This reoccurance will lead into the final stage of the GAS model.
During this phase the stress has been ongoing for sometime, not allowing your body to take a break thus the ability to resist is lost. This is primarily due to the adaption energy supply being used up.
This phase is also known as adrenal fatigue, maladaption, or even dysfunction.
This phase of the GAS model is the most harmful to your health!
The long-term stress causes nerve damage in tissues and organs. The hippocampus section of your brain is most susceptible to damage. Cognition and memory deteriorate and will lead to anxiety and depression.
There will also be negative outcomes for the function of the autonomic nervous system. This will increase chances of heart disease, rheumatoid arthritis, high blood pressure and other related illnesses.
You can see how important it is for your body to react to stress. Hans Seyle said it the best in his journal...
"Adaptability and resistance to stress are fundamental prerequisites for life, and every vital organ and function participates in them"
Thank you and I hope you were both entertained and informed about the effects stress has on your body!
"Molecular Mechanisms of Cell Function" -- Malgosia Wilk-Blaszczak
Roberts, Ff., and HANS SELYE. "Stress and the General Adaptation Syndrome." British Medical Journal 2.4670 (1950): 104-05. Print. < >