Adaptation Syndrome

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Related to Adaptation Syndrome: local adaptation syndrome, Space adaptation syndrome

adaptation syndrome

[‚a‚dap′tā·shən ‚sin‚drōm]
Endocrine-mediated stress reaction of the body in response to systemic injury; involves an initial stage of shock, followed by resistance or adaptation and then healing or exhaustion.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Adaptation Syndrome


the sum total of the nonspecific defense reactions that arise in the organism of animals and man upon the action of external and internal stimuli of considerable strength and duration. These reactions promote the restoration of disturbed equilibrium and are aimed at maintaining homeostasis—the constancy of the internal environment of the organism.

The concept of the adaptation syndrome was proposed by the Canadian scientist H. Selye in 1936. The factors evoking the adaptation syndrome—for instance, infection, abrupt temperature changes, physical and mental trauma, a high muscle load, loss of blood, ionizing radiation, and the action of many drugs—are called stressors, and the condition of the organism that develops during their action is known as stress. The main symptoms of the adaptation syndrome are an increase in the size of the adrenal cortex and intensification of its secretory activity, decreases in the size of the thymus, spleen, and lymph nodes, changes in blood composition (leukocytosis, lymphopenia, and eosinopenia), a disturbed metabolism (with a prevalence of degradation processes and leading to loss of weight), and a decrease in blood pressure.

The adaptation syndrome develops in two or three stages. The first stage, or alarm reaction, lasts six to 48 hours and is divided into phases of shock and counter-shock; during this stage, increased amounts of adrenal hormones (glucocorticoids and adrenaline) are produced and enter the blood, and the body reorganizes and adapts to the difficult conditions. The second stage is resistance, during which the immunity of the organism to various influences is greater; by the end of this stage, the condition of the organism is normalized and recovery sets in. If the action of the stimuli is of great strength and duration, the third stage, exhaustion, sets in; this stage may end in the death of the organism.

Reflex processes (defense, vasomotor, and other reflexes) are the initial component of the body’s adaptation to unusual conditions; then humoral stimuli (adrenaline, histamine, and decomposition products of damaged tissues) go into action via the blood, lymph, and so on. All this triggers the mechanisms that ensure the adaptive reaction of the organism, primarily the reticular formation of the brain and the system hypothalamus-hypophysis-adrenal glands. The cells of the hypothalamus produce a releasing factor, under the influence of which the formation and release into the bloodstream of adrenocorticotropin by the hypophysis is increased; the adrenocorticotropin stimulates the activity of the adrenal cortex—that is, the production of glucocorticoids. Simultaneously, other humoral and neural mechanisms and the nervous system as a whole are drawn into the reaction.


Gorizontov, P. D. “Rol’ gormonov v obshchem adaptatsionnom sindrome i bolezni adaptatsii.” Klinich. meditsina, 1956, vol. 34, no. 7.
Selye, H. Ocherki ob adaptatsionnom sindrome. Moscow, 1960. (Translated from English.)
Lissák, K., and E. Endröczi. Neiroendokrinnaia reguliatsiia adaptatsionnoi deiatel’nosti. Budapest, 1967. [Translated from Hungarian.]


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The value, then, of corticosteroid release as an index would be precisely that it is not stress itself (there being many unique stresses, each requiring its own measure) but is rather part of the general adaptation syndrome and hence is a general index of the presence of stresses of many different kinds.
The general adaptation syndrome and diseases of adaptation.
Poor adaptation syndrome in newborns exposed in late pregnancy to a selective serotonin reuptake inhibitor (SSRI) or selective norepinephrine reuptake inhibitor (SNRI)--with symptoms such as jitteriness, being inconsolable, and difficulty in feeding--were first described several years ago.
Hans Selye published his classic text, The Strees of Life, he probably had no idea that strength and conditioning coaches would one day reference his proposed General Adaptation Syndrome (G.A.S.) with ubiquitous fervor.
The technology, which was initially designed to help with space adaptation syndrome (similar to motion sickness), is being examined as a possible treatment for anxiety, nausea, and other stress-related disorders.
A recently published article addressing the risks of SSRIs in infertile women, which discusses, among other issues, the risk of SSRIs during pregnancy across outcomes of miscarriage, birth defects, neonatal side effects (so-called neonatal adaptation syndrome), and persistent pulmonary hypertension of the newborn (PPHN), is an example of how published reports and reviews frequently confuse more than they inform.
His theory of general adaptation syndrome (GAS) was based on observing the nearly uniform changes that occurred in mice after exposure to poisonous chemicals and agents.
HIT supporters relate their theory of musculoskeletal adaptation to the General Adaptation Syndrome (GAS) first described by Hans Selye (8).
On the other hand, studies indicating that babies whose mothers use SSRIs during pregnancy might have symptoms of transient jitteriness for a period following birth (neonatal adaptation syndrome) have been more consistent--and this is generally accepted as a real risk following about 20%-25% of deliveries.