homeostasis

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Related to Homeostatic mechanism: homeostasis, Homoeostasis

homeostasis

 [ho″me-o-sta´sis]
the tendency of biological systems to maintain relatively constant conditions in the internal environment while continuously interacting with and adjusting to changes originating within or outside the system. See also balance and equilibrium. adj., adj homeostat´ic. The term is considered by some to be misleading in that the word element-stasis implies a static or fixed and unmoving state, whereas homeostasis actually involves continuous motion, adaptation, and change in response to environmental factors.

It is through homeostatic mechanisms that body temperature is kept within normal range, the osmotic pressure of the blood and its hydrogen ion concentration (pH) is kept within strict limits, nutrients are supplied to cells as needed, and waste products are removed before they accumulate and reach toxic levels of concentration. These are but a few examples of the thousands of homeostatic control systems within the body. Some of these systems operate within the cell and others operate within an aggregate of cells (organs) to control the complex interrelationships among the various organs.

ho·me·o·sta·sis

(hō'mē-ō-stā'sis, -os'tă-sis), Although the principal stress correctly falls on the third syllable in this word, the pronunciation homeosta'sis is more usual in the U.S. Do not confuse this word with hemostasis.
1. The state of equilibrium (balance between opposing pressures) in the body with respect to various functions and to the chemical compositions of the fluids and tissues.
2. The processes through which such bodily equilibrium is maintained.
[homeo- + G. stasis, standing]

homeostasis

(hō′mē-ō-stā′sĭs)
n.
A state of equilibrium, as in an organism or cell, maintained by self-regulating processes: The kidneys maintain homeostasis in the body by regulating the amount of salt and water excreted.

ho′me·o·stat′ic (-stăt′ĭk) adj.

homeostasis

Physiology The dynamic constancy of the internal environment; the self-regulating biologic processes that maintain an organism's equilibrium; the ability to maintain a constant state under various conditions of stress

ho·me·o·sta·sis

(hō'mē-ō-stā'sis)
1. The state of equilibrium (balance between opposing pressures) in the body with respect to various functions and to the chemical compositions of the fluids and tissues.
2. The processes through which such bodily equilibrium is maintained.
[G. homoios, similar, + stasis, a standing, fr. istēmi, to stand]

homeostasis

The principle of self-regulating information feedback by which constant conditions are maintained in a biological system such as the human body. Homeostasis is essential to life and applies to thousands of bodily parameters. Some of the more obvious examples are temperature regulation, blood acidity control, blood pressure control, heart rate, blood sugar levels and hormone secretion.

homeostasis

the maintenance by an organism of a constant internal environment; an example is the regulation of blood sugar levels by insulin. The process involves self-adjusting mechanisms in which the maintenance of a particular level is initiated by the substance to be regulated. See also FEEDBACK MECHANISM.

Homeostasis

The tendency of a family system to maintain internal stability and resist change.

ho·me·o·sta·sis

(hō'mē-ō-stā'sis)
1. State of equilibrium in the body with respect to various functions and to the chemical compositions of fluids and tissues.
2. Processes through which bodily equilibrium is maintained.
[G. homoios, similar, + stasis, a standing, fr. istēmi, to stand]
References in periodicals archive ?
Studies aimed at the identification of genes that mediate the activity-dependent regulation of inhibitory synapses formation during development, revealed that NPAS4 is an IEG induced by neuronal activity that seems to lie behind homeostatic mechanisms that keep neuronal firing in response to sensory experience within normal levels [38].
Ovarian hormone variations along the menstrual cycle are associated with corresponding significant changes in multiple neuro-humoral homeostatic mechanisms regulating the cardiovascular system.
Building on premises congenial to the non-cognitivist tradition, we make the following claims: (1) In paradigmatic cases, wrongness-judgments constitute a certain complex but functionally unified state, and paradigmatic wrongness-judgments form a functional kind, preserved by homeostatic mechanisms. (2) Because of the practical function of such judgments, we should expect judges' intuitive understanding of agreement and disagreement to be accommodating, treating states departing from the paradigm in various ways as wrongness-judgments.
Previous results in our laboratory showed that activation of CB1R in the paraventricular nucleus of the hypothalamus prevented the natural satiety sequence by modulating homeostatic mechanisms (Escartin-Perez, et al., 2009); nevertheless activation of cannabinoid receptors in the NAcS might also stimulate feeding by a different mechanism, for instance stimulating the hedonically positive sensory properties of food.
All body-centered therapeutic disciplines have the same objective: to manually regulate homeostatic mechanisms. Each technique is distinctively different, and favors only a specific aspect of bioregulation.
Potassium is the principal intracellular cation, and maintenance of its distribution between the intracellular and the extracellular compartments relies on several homeostatic mechanisms. When these mechanisms are perturbed, hypokalemia or hyperkalemia may occur [1].
After 4 hours, the stratum corneum's homeostatic mechanisms had raised natural moisturizing factor and reduced pH to normal levels.
The occurrence of changes in [beta]-NTP observed in methadone-maintained individuals during a state of active prolonged wakefulness following sleep deprivation that continues on into the morning following recovery sleep may be indicative of a greater disruption to sleep homeostatic mechanisms in methadone-maintained versus cocaine dependent individuals.
In domestic cows, it has been proposed that intravenous infusion of edetate disodium ([Na.sub.2] EDTA) disrupts calcium homeostatic mechanisms. (19) Additionally, although there are no reported human cases of Ca[Na.sub.2]-EDTA--induced hypocalcemia, there are at least 2 reports of pediatric deaths attributed to [Na.sub.2]-EDTA administration and associated hypocalcemia.
Furthermore, Cu absorption and homeostatic mechanisms are very different between bovine and porcine species (Wapnir, 1998; Spears, 2003) but both species are sensitive to pulmonary hypertension at high altitude.
Indeed, inhaled manganese is delivered to the brain much more efficiently than ingested manganese, because it bypasses normal homeostatic mechanisms.
Homeostatic mechanisms are utilized to maintain appropriate serum iron concentrations, thus preventing neuronal cell damage from iron-mediated free radicals.