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

/ho·meo·sta·sis/ (-sta´sis) a tendency to equilibrium or stability in the normal physiological states of the organism.homeostat´ic

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

[hō′mē·əstā′sis]
Etymology: Gk, homoios + stasis, standing still
a relative constancy in the internal environment of the body, naturally maintained by adaptive responses that promote healthy survival. Various sensing, feedback, and control mechanisms function to effect this steady state. Some of the key control mechanisms are the reticular formation in the brainstem and the endocrine glands. Some of the functions controlled by homeostatic mechanisms are heartbeat, hematopoiesis, blood pressure, body temperature, electrolytic balance, respiration, and glandular secretion. homeostatic, 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.

homeostasis

within-body processes that maintain internal equilibrium

homeostasis,

n the state of balance in the internal environment of the body achieved by various control mechanisms.

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]

homeostasis (hō´mēōstā´sis),

n the term used to describe the tendency toward physiologic equilibration (e.g., acid-base balance, pH level of blood, blood sugar level).
homeostasis, cell,
n the tendency of biologic tissues and processes to maintain a constancy of environment consistent with their vitality and well being. For cells to maintain their stability or equilibrium, the cell membranes must be in continuous interaction with both the internal (intracellular) environment and the external (extracellular) environment. When the equilibrium of any component is disturbed, the interaction permits automatic readjustment by giving rise to stimuli that result in restoration of the equilibrium.

homeostasis

a tendency of biological systems to maintain stability while continually adjusting to conditions that are optimal for survival.
Homeostatic mechanisms are necessary for the body to regain its balance when disease or injury occurs and to maintain that balance if it is to remain healthy.
References in periodicals archive ?
2) Tess, the giant robot, teaches visitors about homeostasis - complete with flowing blood and pounding heart - at the California Science Center.
Both nutrients are known to influence calcium homeostasis, but the relative contributions of each haven't been studied before, they said (JAMA 2005:294:2336-41).
ILC3-specific loss and gain of function mutant mice for neuroregulatory receptors will be used to define the role of these molecules in ILC3 function, mucosal homeostasis, gut defence and microbial ecology.
Targeting protein homeostasis has been validated by the clinical and commercial success of VELCADE (bortezomib) and KYPROLIS (carfilzomib) in multiple myeloma; however these agents are generally not effective in solid tumors owing to both chemistry and pharmacology limitations.
2001) suggest that Pb might act on calcium channels to alter intracellular calcium homeostasis in bone cells (Pounds 1984; Rosen and Pounds 1989; Schanne et al.
Spontaneous adverse event reports over 6 years show that gatifloxacin was associated with 80% of 568 glucose homeostasis abnormality adverse event reports and 68% of 25 such events involving fatality that were associated with the use of ciprofloxacin, levofloxacin, moxifloxacin, or gatifloxacin.
The companion volume, Homeostasis and Toxicology of Essential Metals, Volume 31A, covers metals that are either proven to be or are strongly suspected to be essential in trace amounts, yet are toxic in higher doses.
Objective: The immune system with its complex interactions of cells and molecules needs a very tight and specific interplay of control elements to ensure the establishment and re-establishment of immune homeostasis after challenges.
which is developing novel oral biologics to restore cellular homeostasis in a range of serious medical conditions, today announced the issuance by the United States Patent and Trademark Office (USPTO) of US Patent No.
They present the material in three main parts dealing with basic physiochemical concepts, fluid and electrolyte homeostasis, and acid-base homeostasis, covering aspects related to both normal and abnormal physiology in each of the latter two sections.
The tissue-specific metabolism of GC by these enzymes is important for mineralocorticoid (MC) and GC receptor occupancy and seems to play a crucial role in the pathogenesis of diseases such as apparent MC excess syndrome, and may play roles in hypertension, obesity and impaired hepatic glucose homeostasis.
A sampling of topics: transcriptional control of energy homeostasis through the PGC1 coactivators, lipid-induced metabolic dysfunction in skeletal muscle, endoplasmic reticulum stress and inflammation in obesity and type 2 diabetes, the impact of insulin resistance on macrophage death pathways in advanced atherosclerosis, cide proteins and the development of obesity, and adiponectin and adiponectin receptors in obesity-linked insulin resistance.