March 1[ edit ] Plants and their production of oxygen[ edit ] I was wondering if it was possible for future moon colonization for the colony's oxygen supply to be totally relient on plants? Could the colonists provide the plants with their carbon dioxide while the plants supplied them with oxygen?
The essence of this report was that rats exposed to a variety of nocuous or toxic agents e. The enlargement of the adrenals, the profound shrinkage of the thymus and of lymphoid organs and hemorrhage, especially in the gastrointestinal tract, has been noted as the most characteristic features of the reaction.
If the treatment was continued with relatively slight injuries or small drug doses, the animals became resistant and their organs returned to the normal state.
With further treatment the animals lost their resistance and succumbed with symptoms similar to those seen initially. These included physical, chemical agents and emotional factors.
During this work it was thought for a while that adrenal enlargement and involution of lymphoid organs was specific for the putative hormone, but extensive attempts to purify the substance failed and the activity was always lost in the end.
At some point it occurred to Selye that the reaction could, in fact, represent a non-specific response to noxious agents and, indeed, when he performed the proper experiments, his suspicion turned out to be correct. This is what was reported in the Nature article.
In the same year a longer article was published by him in the British Journal of Experimental Pathology , where he demonstrated that the involution of the thymus was, in fact, mediated by the adrenal gland as it was absent in adrenalectomized animals after stress.
This observation led to an extensive study of steroid compounds in rats and also in chicken. He was the first to establish that the bursa of Fabricius is an organ which is extremely sensitive to steroid hormones.
By he had a considerable amount of experimental data on the general adaptation syndrome which was presented in a review published in the Journal of Clinical Endocrinology  as the first comprehensive outline of the stress concept.
In this paper he predicted that diseases may develop as the result of maladaptation to stressful stimuli. A diagram is presented indicating that after stress exposure the initial reaction is shock, which is followed by a countershock phase and later on by the development of resistance.
Eventually, resistance may go into exhaustion and death may ensue. A summary figure was presented in this article Fig. Selye knew a lot about the mechanisms of stress. He appreciated the endocrine, immune and metabolic changes involved.
At that time it was not established that the pituitary gland was regulated by the hypothalamus. We brought this figure up to date; which is indicated with dotted lines.
The corticotropic hormone excess causes enlargement of the adrenal cortex with signs of increased corticosteroid hormone production which in turn causes alterations in the carbohydrate and electrolyte metabolism, as well as the atrophy of the thymus and other lymphoid organs.
Actually, this is a fairly accurate outline of the acute phase response, as we call it today, with its neuroendocrine, metabolic and immunological alterations .
In Selye observed that the injection of egg white to rats evoked an inflammatory response which could be inhibited by cortisone or by the administration of purified ACTH. Deoxycorticosterone acetate, a mineralo-corticoid compound, tended to aggravate the reactions .
These experiments initiated his interest in inflammation, which became the most lasting topic in his research and led to the proposition later that diseases like rheumatoid arthritis, anaphylaxis, etc.
Hormonal regulation of inflammation. This figure is actually valid today. Growth hormone and prolactin do indeed promote the inflammatory response, whereas glucocorticoids inhibit it and the adrenal androgen, dehydroepiandrosterone, promotes the immune and inflammatory reactions.
The pituitary gland stimulates inflammation directly by somatotropic growth hormone STH. The adrenocorticotropic hormone ACTH -adrenal axis produces pro-inflammatory P-flogistic and anti-inflammatory A-anti flogistic corticosteroid hormones.The legacy of Hans Selye and the origins of stress research: A retrospective 75 years after his landmark brief “Letter” to the Editor# of Nature SANDOR SZABO1,*, YVETTE TACHE2, & ARPAD SOMOGYI3,* 1VA Long Beach Healthcare System and Departments of Pathology and Pharmacology, University of California-Irvine, Long Beach, CA, USA.
In an endocrinologist, Hans Sdye, discovered stress. Stress is present in everybody.
It occurs daily in people s lives. Stress is a body condition that occurs in response to actual or anticipated difficulties in life (Rice, ). Stress can also be defined as the sum of physical and m.
In fact, the latest theory about why we have stress basically argues that stress is not for immediate survival, but that without stress, we wouldn’t actually have the ability to learn from experience.
I think that’s a radical rethinking of why we have stress. Without that we are helpless to know who we are, seeing as the Christ emerges from us organically and is a true reflection of the many but Miley Cyrus is a contrivance along with all the other.
“We are attempting to take the emotion out of the word stress to help people identify it as the gap between demand and capacity, to recognize the early signs when stress is too much or goes on.
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