homeostasis

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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]