What is the stress response?

Stress is not directly observable but the results of the bodies adaptation to it is. Walter Cannon, who authored a book titled, Wisdom of  the Body, was an early researcher that labeled this observable adaptation  the fight-or-flight response which is briefly simplified as follows:

When we encounter a stressor the sensory input passes the signal to/ or from the limbic system via of the reticular activating system (RAS) which signals the thalamus to relay the signal to the hypothalamus. The hypothalamus activates the autonomic nervous system and the endocrine system. The autonomic nervous system is activated by direct nerves connected from the posterior hypothalamus to the adrenal medulla which secretes adrenaline and nor adrenaline. The Anterior of the hypothalamus secretes corticotrophin releasing factor (CRF) which instructs the pituitary to secrete adrenocorticotropic hormone (ACTH) which in turn activates the adrenal cortex to release corticoids, namely cortisol and aldosterone. Cortisol provides fuel for battle by signaling the liver to release glycogen, or if lacking, initiates gluconeogenesis. Aldosterone increases blood pressure. The hypothalamus also secretes thyrotropic hormone releasing factor (TRF) which instructs the pituitary to release thyrotropic hormone (TTH) and activates the thyroid to release thyroxin. In addition the pituitary activates oxytocin and vasopressin which increases the tension in the muscles.


In short: When the stress response is activated various symptomatic changes are noticeable such as: increases in heart beat, higher blood pressure, moisture on the skin, dilated pupils, hydrochloric acid is secreted in the stomach, and other metabolic rate changes. White blood cells, namely, the phagocytes and the lymphocytes, notably the (T and B cells) are lowered in numbers. Any situation that decreases the number of your white blood cells directly threatens your health.  In addition when the stress response is activated heart rate increases, coronary arteries dilate, abdominal arteries constrict, pupils dilate, bronchial tubes dilate, glucose is released from the liver and basal metabolic rate increases. Under these conditions the cerebral cortex makes judgments of the events as either  good or bad. It is only under the influence of the parasympathetic branch of the autonomic nervous system that you remain calm and rational.

Hans Sleeve, the father of stress, in his book titled, The Stress of Life, maintained that stress was not simply the activation of the autonomic and endocrine system. He maintained that it was only after damage was determined by its prolonged activation. that stress was implicated. In a somewhat vague way  he indicated that stress was a state manifested by a specific syndrome which consists of all the nonspecifically induced changes within a biologic system.   For example he noted that pigmentation of the entire skin from sunlight was a nonspecific change in the bodies adaptation, whereas developing a freckle on the nose was specific.[3] Jerrold Greenberg in his book titled, Stress Management, cites other researchers who have maintained that stress was a specific response to what he refers to as a "stress reactivity"

Search the Internet or other sources to examine different theories or views of stress. Develop your favorite operational definition of stress and give an example. Operational definition indicates that the definition includes "what must be done in order to produce and recognize stress. Give an example what you think is not stress. For example, is muscle tension stress? Under what conditions might it be so, and under what conditions might it not be?

Include the Web site and/ or an abstract  and send an abbreviated commentary of the article. You may see the following example http://helping.apa.org/work/stress4.htm

 1. Hans Selye, The Stress of  Life,  New York: McGraw-Hill Book Co.,1978, page 64,2. Ibid., page 67
 3. Jerrold S. Greenberg,  Comprehensive Stress Management, 6 ed. ,Boston: McGraw-Hill, 1999, p.8

E-mail:  rbrehm@msn.com. Copyright 1998  [Robert Brehm]. All rights reserved.