ⓘ Homeostasis ..

Homeostasis

In biology, homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. This dynamic state of equilibrium is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits. Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these varia ...

Allostasis

Allostasis is the process of achieving stability, or homeostasis, through physiological or behavioral change. This can be carried out by means of alteration in HPA axis hormones, the autonomic nervous system, cytokines, or a number of other systems, and is generally adaptive in the short term. Allostasis is essential in order to maintain internal viability amid changing conditions. Allostasis provides compensation for various problems, such as in compensated heart failure, compensated kidney failure, and compensated liver failure. However, such allostatic states are inherently fragile, and ...

Baroreceptor

Baroreceptors are sensors located in the carotid sinus and in the aortic arch. They sense the blood pressure and relay the information to the brain, so that a proper blood pressure can be maintained. Baroreceptors are a type of mechanoreceptor sensory neuron that are excited by a stretch of the blood vessel. Thus, increases in the pressure of blood vessel triggers increased action potential generation rates and provides information to the central nervous system. This sensory information is used primarily in autonomic reflexes that in turn influence the heart cardiac output and vascular smo ...

Daisyworld

Daisyworld, a computer simulation, is a hypothetical world orbiting a star whose radiant energy is slowly increasing or decreasing. It is meant to mimic important elements of the Earth-Sun system, and was introduced by James Lovelock and Andrew Watson in a paper published in 1983 to illustrate the plausibility of the Gaia hypothesis. In the original 1983 version, Daisyworld is seeded with two varieties of daisy as its only life forms: black daisies and white daisies. White petaled daisies reflect light, while black petaled daisies absorb light. The simulation tracks the two daisy populatio ...

Enantiostasis

Enantiostasis is the ability of an open system, especially a living organism, to maintain and conserve its metabolic and physiological functions in response to variations in an unstable environment. Estuarine organisms typically undergo enantiostasis in order to survive with constantly changing salt concentrations. The Australian NSW Board of Studies defines the term in its Biology syllabus as "the maintenance of metabolic and physiological functions in response to variations in the environment". Enantiostasis is not a form of classical homeostasis, meaning "standing at a similar level," w ...

Evolution of molecular chaperones

Chaperones, also called molecular chaperones, are proteins that assist other proteins in assuming their three-dimensional fold, which is necessary for protein function. However, the fold of a protein is sensitive to environmental conditions, such as temperature and pH, and thus chaperones are needed to keep proteins in their functional fold across various environmental conditions. Chaperones are an integral part of a cells protein quality control network by assisting in protein folding and are ubiquitous across diverse biological taxa. Since protein folding, and therefore protein function, ...

                                     

ⓘ Homeostasis

  • environment. Thus, to Barcroft homeostasis was not only organized by the brain - homeostasis served the brain. Homeostasis is an almost exclusively biological
  • Acid base homeostasis is the homeostatic regulation of the pH of the body s extracellular fluid ECF The proper balance between the acids and bases
  • hypothalamic pituitary thyroid axis HPT axis for short, a.k.a. thyroid homeostasis or thyrotropic feedback control is part of the neuroendocrine system
  • In biology, energy homeostasis or the homeostatic control of energy balance, is a biological process that involves the coordinated homeostatic regulation
  • one of the ways mental developmental homeostasis has been researched. One way physical developmental homeostasis was tested was in the facial symmetry
  • Hosker JP, Rudenski AS, Naylor BA, Treacher DF, Turner RC 1985 Homeostasis model assessment: insulin resistance and beta - cell function from fasting
  • Schulkin 2003 This is in difference to homeostasis which occurs in response to subtle ebb and flow. Both homeostasis and allostasis are endogenous systems
  • iron metabolism is the set of chemical reactions that maintain human homeostasis of iron at the systemic and cellular level. Iron is both necessary to
  • 2000 The extreme views of risk homeostasis have attracted little support O Neill Williams 1998 Risk homeostasis is not a theory. It is a hypothesis
  • healthy aging, resistance to environmental stresses, and to minimize homeostasis perturbations by pathogens such as viruses. Mechanisms by which proteostasis