The Brain on Stress
Everyday stress in small doses is normal.
Our bodies have the ability to cope with, and heal from this type of stress. It is the chronic type of stress known as distress, that is killing us. It is toxic to every organ in our body and lethal to our health. This is a subject that could fill thousands of books and not cover all the damage inflicted by chronic stress. In order to focus on the larger picture, lets begin with a portion of the brain called the hypothalamus.
Through research, scientists have shown that prolonged stress can shrink the hypothalamus. The hypothalamus is a part of the brain that connects with structures of the endocrine and nervous systems enabling it to play a vital role in maintaining homeostasis, the ability of our entire system to maintain internal stability. It does this in part by controling body temperature, hunger, thirst, fatigue, sleep, and circadian rythms.
Circadian rhythms, also known as the body clock, are physical, mental, and behavioral changes that follow an approximate 24-hour cycle, responding primarily to light and darkness in an organism’s environment. They are found in most living things. Circadian rhythms allow organisms to anticipate and prepare for precise and regular environmental changes.
Circadian rhythmicity is present in the sleeping and feeding patterns of animals, including human beings. There are also clear patterns of core body temperature, brain wave activity, hormone production, cell regeneration and other biological activities. Timely prediction of seasonal periods of weather conditions, food availability or predator activity is crucial for survival of any species.
If prologed chronic stress can shrink the hypthalamus, which controls our bodies ability to maintain internal stabiltiy and ciradian rythms, then our natural ability to detect danger is at risk. It would clearly affect all our bodies biological ativities.
In addition to shrinking the hypthalamus, stress also affects your brain in other ways, causing the release of neurotransmitters. Dopamine, norepinephrine, and epinephrine (adrenaline) are just a few of these powerful chemical messengers.
The hypothalamic and pituitary adrenal portion of your brain releases steroid hormones. One of these hormones is Cortisol, a primary stress homorne. If too much Cortisol hormone is constantly released under chronic stress conditions, it has negative effects throughout the body, including increasing the heart rate.
This in turn effects the heart, lungs, and circulatory system. Blood flow may increase 300 to 400 percent resulting in higher blood pressure. Because the blood is diverted to the heart and other muscle tissue the skin may become clammy and the throat and mouth dry. Under extreme conditions, the bodies digestive capabilities may even shut down. This is just the tip of the iceberg. Virtually all organs suffer from prolonged exposure to chronic stress.