State of homeostasis under altered conditions. The concept of homeostasis. Manifestation of homeostasis at different levels of organization of biological systems. Structural homeostasis, mechanisms of its maintenance

In biology, this is maintaining the constancy of the internal environment of the body.
Homeostasis is based on the body’s sensitivity to the deviation of certain parameters (homeostatic constants) from a given value. Limits of permissible fluctuations of the homeostatic parameter ( homeostatic constant) can be wide or narrow. Narrow limits have: body temperature, blood pH, blood glucose levels. Wide limits have: blood pressure, body weight, concentration of amino acids in the blood.
Special intraorganismal receptors ( interoreceptors) respond to deviations of homeostatic parameters from specified limits. Such interoreceptors are found inside the thalamus, hypothalamus, in blood vessels and in organs. In response to parameter deviations, they trigger restorative homeostatic reactions.

General mechanism of neuroendocrine homeostatic reactions for internal regulation of homeostasis

The parameters of the homeostatic constant deviate, the interoceptors are excited, then the corresponding centers of the hypothalamus are excited, they stimulate the release of the corresponding liberins by the hypothalamus. In response to the action of liberins, hormones are released by the pituitary gland, and then, under their action, hormones of other endocrine glands are released. Hormones, released from the endocrine glands into the blood, change the metabolism and functioning of organs and tissues. As a result, the established new mode of operation of organs and tissues shifts the changed parameters towards the previous set value and restores the value of the homeostatic constant. That's how general principle restoration of homeostatic constants when they deviate.

2. In these functional nerve centers, the deviation of these constants from the norm is determined. Deviation of constants within given limits is eliminated due to the regulatory capabilities of the functional centers themselves.

3. However, when any homeostatic constant deviates above or below acceptable limits, the functional centers transmit excitation higher: to "need centers" hypothalamus. This is necessary in order to switch from internal neurohumoral regulation of homeostasis to external - behavioral.

4. Excitation of one or another need center of the hypothalamus forms a corresponding functional state, which is subjectively experienced as a need for something: food, water, heat, cold or sex. A psycho-emotional state of dissatisfaction arises that activates and encourages action.

5. To organize purposeful behavior, it is necessary to select only one of the needs as a priority and create a working dominant to satisfy it. It is believed that main role The tonsils of the brain (Corpus amygdoloideum) play a role in this. It turns out that, based on one of the needs that the hypothalamus forms, the amygdala creates a leading motivation that organizes goal-directed behavior to satisfy only this one selected need.

6. The next stage can be considered the launch of preparatory behavior, or the drive reflex, which should increase the likelihood of launching the executive reflex in response to the trigger stimulus. The drive reflex encourages the body to create a situation in which the likelihood of finding an object suitable to satisfy the current need will be increased. This could be, for example, moving to a place rich in food, or water, or sexual partners, depending on the driving need. When, in the achieved situation, a specific object is discovered that is suitable for satisfying a given dominant need, it triggers executive reflex behavior aimed at satisfying the need with the help of this particular object.

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Homeostasis Systems - A detailed educational resource on homeostasis.

HOMEOSTASIS, homeostasis (homeostasis; Greek, homoios similar, the same + stasis state, immobility), - the relative dynamic constancy of the internal environment (blood, lymph, tissue fluid) and the stability of the basic physiological functions (circulation, respiration, thermoregulation, metabolism, etc.) human and animal bodies. Regulatory mechanisms supporting physiol. the state or properties of cells, organs and systems of the whole organism at an optimal level are called homeostatic.

As is known, living cell represents a mobile, self-regulating system. Her internal organization supported by active processes aimed at limiting, preventing or eliminating shifts caused by various influences from the environment and internal environment. The ability to return to the original state after a deviation from a certain average level caused by one or another “disturbing” factor is the main property of the cell. A multicellular organism is a holistic organization whose cellular elements are specialized to perform various functions. Interaction within the body is carried out by complex regulatory, coordinating and correlating mechanisms with the participation of nervous, humoral, metabolic and other factors. Many individual mechanisms regulating intra- and intercellular relationships have, in some cases, mutually opposite (antagonistic) effects that balance each other. This leads to the establishment of a mobile physiol, background (fiziol, balance) in the body and allows the living system to maintain relative dynamic constancy, despite changes in the environment and shifts that arise during the life of the organism.

The term “homeostasis” was proposed in 1929 by Amer. physiologist W. Cannon, who believed that physiol, the processes that maintain stability in the body are so complex and diverse that it is advisable to combine them under common name G. However, back in 1878, C. Bernard wrote that all life processes have only one goal - maintaining the constancy of living conditions in our internal environment. Similar statements are found in the works of many researchers of the 19th and first half of the 20th centuries. [E. Pfluger, S. Richet, Frederic (L. A. Fredericq), I. M. Sechenov, I. P. Pavlov, K. M. Bykov, etc.]. The works of L. S. Stern (o.), devoted to the role of barrier functions (see) regulating the composition and properties of the microenvironment of organs and tissues, were of great importance for the study of the problem of G.

The very idea of ​​G. does not correspond to the concept of stable (non-fluctuating) equilibrium in the body - the principle of equilibrium is not applicable to complex physiol, and biochemical. processes occurring in living systems. It is also incorrect to contrast G. with rhythmic fluctuations in the internal environment (see Biological rhythms). G. in a broad sense, covers issues of the cyclic and phase course of reactions, compensation (see Compensatory processes), regulation and self-regulation of physiology, functions (see Self-regulation of physiological functions), the dynamics of the interdependence of nervous, humoral and other components of the regulatory process. G.'s boundaries can be rigid and flexible, and vary depending on individual age, gender, social, and profession. and other conditions.

Of particular importance for the life of the body is the constancy of the composition of the blood - the fluid matrix of the body, as W. Cannon puts it. The stability of its active reaction (pH), osmotic pressure, ratio of electrolytes (sodium, calcium, chlorine, magnesium, phosphorus), glucose content, number of formed elements, etc. is well known. So, for example, blood pH, as a rule, does not goes beyond 7.35-7.47. Even severe disorders of acid-base metabolism with patol, the accumulation of acids in tissue fluid, for example, with diabetic acidosis, have very little effect on the active reaction of the blood (see Acid-base balance). Despite the fact that the osmotic pressure of blood and tissue fluid is subject to continuous fluctuations due to the constant supply of osmotically active products of interstitial metabolism, it remains at a certain level and changes only in some severe patol conditions (see Osmotic pressure). Maintaining a constant osmotic pressure is of paramount importance for water metabolism and maintaining ionic balance in the body (see Water-salt metabolism). The concentration of sodium ions in the internal environment is the most constant. The content of other electrolytes also varies within narrow limits. Availability large quantity osmoreceptors (see) in tissues and organs, including in the central nervous formations (hypothalamus, hippocampus), and a coordinated system of regulators of water metabolism and ion composition allows the body to quickly eliminate shifts in the osmotic pressure of the blood that occur, for example, when introducing water into the body.

Despite the fact that blood represents the general internal environment of the body, the cells of organs and tissues do not directly come into contact with it. In multicellular organisms, each organ has its own internal environment (microenvironment), corresponding to its structural and functional characteristics, and normal condition organs depends on the chemical composition, physical-chemical, biol, and other properties of this microenvironment. Its G. is determined by the functional state of histohematic barriers (see Barrier functions) and their permeability in the directions blood -> tissue fluid, tissue fluid -> blood.

The constancy of the internal environment for the activity of the center is of particular importance. n. pp.: even minor chemicals. and physical-chemical shifts that occur in the cerebrospinal fluid, glia and pericellular spaces can cause a sharp disruption in the course of vital processes in individual neurons or in their ensembles (see Blood-brain barrier). A complex homeostatic system, including various neurohumoral, biochemical, hemodynamic and other regulatory mechanisms, is the system for ensuring the optimal level of blood pressure (see). In this case, the upper limit of the blood pressure level is determined by the functionality of the baroreceptors of the body’s vascular system (see Angioceptors), and the lower limit is determined by the body’s blood supply needs.

The most advanced homeostatic mechanisms in the body of higher animals and humans include processes of thermoregulation (see); In homeothermic animals, temperature fluctuations in the internal parts of the body do not exceed tenths of a degree during the most dramatic changes in temperature in the environment.

Different researchers explain the mechanisms of general biology in different ways. character underlying G. Tuck, W. Cannon special meaning attached to n. pp., L.A. Orbeli considered the adaptive-trophic function of the sympathetic nervous system to be one of the leading factors. The organizing role of the nervous apparatus (the principle of nervism) underlies widely known ideas about the essence of the principles of G. (I. M. Sechenov, I. P. Pavlov, A. D. Speransky, etc.). However, neither the dominant principle (A. A. Ukhtomsky), nor the theory of barrier functions (L. S. Stern), nor the general adaptation syndrome (G. Selye), nor the theory of functional systems (P. K. Anokhin), nor the hypothalamic regulation of G (N.I. Grashchenkov) and many other theories do not completely solve the problem of G.

In some cases, the idea of ​​G. is not entirely legitimately used to explain isolated physiol, conditions, processes and even social phenomena. This is how the terms “immunological”, “electrolyte”, “systemic”, “molecular”, “physico-chemical”, “genetic homeostasis”, etc., found in the literature, arose. Attempts were made to reduce the problem of G. to the principle of self-regulation (see Biological system, autoregulation in biological systems). An example of a solution to the problem of G. from the perspective of cybernetics is Ashby’s attempt (W. R. Ashby, 1948) to construct a self-regulating device that models the ability of living organisms to maintain the level of certain quantities within physiol, acceptable limits (see Homeostat). Some authors consider the internal environment of the body in the form of a complex chain system with many “active inputs” (internal organs) and individual physiol indicators (blood flow, blood pressure, gas exchange, etc.), the value of each of which is determined by the activity of the “inputs”.

In practice, researchers and clinicians are faced with questions of assessing the adaptive (adaptive) or compensatory capabilities of the body, their regulation, strengthening and mobilization, and predicting the body's responses to disturbing influences. Some states of vegetative instability, caused by insufficiency, excess or inadequacy of regulatory mechanisms, are considered “diseases of homeostasis”. With a certain convention, these may include functional disturbances in the normal functioning of the body associated with its aging, forced restructuring of biological rhythms, some phenomena of vegetative dystonia, hyper- and hypocompensatory reactivity under stressful and extreme influences (see Stress), etc.

To assess the state of homeostatic mechanisms in physiol, experiment and in wedge, practice, a variety of dosed functional tests are used (cold, heat, adrenaline, insulin, mesaton, etc.) with determination of the ratio of biologically active substances (hormones, mediators, metabolites) in the blood and urine. etc.

Biophysical mechanisms of homeostasis

From a chemical point of view. In biophysics, homeostasis is a state in which all processes responsible for energy transformations in the body are in dynamic equilibrium. This state is most stable and corresponds to physiol, the optimum. In accordance with the concepts of thermodynamics (see), an organism and a cell can exist and adapt to such environmental conditions under which a stationary flow of physical-chemical can be established in a biol system. processes, i.e. homeostasis. The main role in the establishment of gas belongs primarily to cellular membrane systems, which are responsible for bioenergetic processes and regulate the rate of entry and release of substances by cells (see Biological membranes).

From this point of view, the main causes of the disorder are non-enzymatic reactions that occur in membranes, unusual for normal life; in most cases, these are oxidation chain reactions involving free radicals that occur in cell phospholipids. These reactions lead to damage structural elements cells and dysfunction of regulation (see Radicals, Chain reactions). The factors that cause G.'s violation also include agents that cause radical formation - ionizing radiation, infectious toxins, certain foods, nicotine, as well as lack of vitamins, etc.

One of the main factors that stabilize the homeostatic state and functions of membranes are bioantioxidants, which inhibit the development of oxidative radical reactions (see Antioxidants).

Age-related features of homeostasis in children

The constancy of the internal environment of the body and the relative stability of physical-chemical. indicators in childhood are provided with a pronounced predominance of anabolic metabolic processes over catabolic ones. This is an indispensable condition for growth (see) and distinguishes the child’s body from the body of adults, in whom the intensity of metabolic processes is in a state of dynamic equilibrium. In this regard, the neuroendocrine regulation of the child’s body turns out to be more intense than in adults. Each age period is characterized specific features G. mechanisms and their regulation. Therefore, severe gastrointestinal disorders, often life-threatening, occur in children much more often than in adults. These disorders are most often associated with the immaturity of the homeostatic functions of the kidneys, with disorders of the functions of the gastrointestinal tract. tract or respiratory function of the lungs (see Breathing).

The growth of a child, expressed in an increase in the mass of its cells, is accompanied by distinct changes in the distribution of fluid in the body (see Water-salt metabolism). The absolute increase in the volume of extracellular fluid lags behind the rate of overall weight gain, so the relative volume of the internal environment, expressed as a percentage of body weight, decreases with age. This dependence is especially pronounced in the first year after birth. In older children, the rate of change in the relative volume of extracellular fluid decreases. The system for regulating the constancy of fluid volume (volume regulation) provides compensation for deviations in water balance within fairly narrow limits. High degree of tissue hydration in newborns and children early age determines the child’s need for water (per unit body weight) is significantly higher than that of adults. Loss of water or its limitation quickly leads to the development of dehydration due to the extracellular sector, i.e., the internal environment. At the same time, the kidneys - the main executive organs in the volumoregulation system - do not provide water savings. The limiting factor of regulation is the immaturity of the renal tubular system. Key Feature G.'s neuroendocrine control in newborns and young children consists of relatively high secretion and renal excretion of aldosterone (see), which has a direct effect on the state of tissue hydration and the function of the renal tubules.

Regulation of osmotic pressure of blood plasma and extracellular fluid in children is also limited. The osmolarity of the internal environment fluctuates over a wider range (+ 50 mOsm/L) than in adults (+ 6 mOsm/L). This is due to the larger body surface area per 1 kg of weight and, therefore, to more significant water losses during respiration, as well as the immaturity of the renal mechanisms of urine concentration in children. G.'s disorders, manifested by hyperosmosis, are especially common in children during the neonatal period and the first months of life; at older ages, hypoosmosis begins to predominate, associated with ch. arr. with yellow-kish. kidney disease or disease. Less studied is the ionic regulation of blood, which is closely related to the activity of the kidneys and the nature of nutrition.

Previously, it was believed that the main factor determining the osmotic pressure of the extracellular fluid was the sodium concentration, but more recent studies have shown that there is no close correlation between the sodium content in the blood plasma and the value of the total osmotic pressure in pathology. The exception is plasmatic hypertension. Consequently, carrying out homeostatic therapy by administering glucose-salt solutions requires monitoring not only the sodium content in the serum or blood plasma, but also changes in the total osmolarity of the extracellular fluid. The concentration of sugar and urea is of great importance in maintaining the general osmotic pressure in the internal environment. The content of these osmotically active substances and their effect on water-salt metabolism in many pathol states can increase sharply. Therefore, for any G. violations, it is necessary to determine the concentration of sugar and urea. Due to the above, in young children, if the water-salt and protein regimes are disturbed, a state of latent hyper- or hypoosmosis, hyperazotemia may develop (E. Kerpel-Froniusz, 1964).

An important indicator characterizing G. in children is the concentration of hydrogen ions in the blood and extracellular fluid. In the antenatal and early postnatal periods, the regulation of acid-base balance is closely related to the degree of oxygen saturation of the blood, which is explained by the relative predominance of anaerobic glycolysis in bioenergetic processes. Moreover, even moderate hypoxia in the fetus is accompanied by the accumulation of milk in its tissues. In addition, the immaturity of the acidogenetic function of the kidneys creates the prerequisites for the development of “physiological” acidosis (see). Due to the peculiarities of G., newborns often experience disorders that border between physiological and pathological.

Restructuring of the neuroendocrine system in puberty is also associated with changes in gastrointestinal tract. However, the functions of the executive organs (kidneys, lungs) reach their maximum degree of maturity at this age, therefore severe syndromes or diseases of gastrointestinal tract are rare;

about compensated changes in metabolism, which can only be detected with biochemical blood tests. In the clinic, to characterize G. in children, it is necessary to examine the following indicators: hematocrit, total osmotic pressure, content of sodium, potassium, sugar, bicarbonates and urea in the blood, as well as blood pH, pO 2 and pCO 2.

Features of homeostasis in old and senile age

The same level of homeostatic values ​​in different age periods is maintained due to various shifts in the systems of their regulation. For example, the constancy of the blood pressure level at a young age is maintained due to a higher cardiac output and low total peripheral vascular resistance, and in the elderly and senile - due to a higher total peripheral resistance and a decrease in cardiac output. With the aging of the body, the constancy of the most important physiol, functions is maintained in conditions of decreasing reliability and reduction of the possible range of physiol, changes in G. The preservation of relative G. with significant structural, metabolic and functional changes is achieved by the fact that at the same time not only extinction, disruption and degradation occurs, but also development of specific adaptive mechanisms. Due to this, a constant level of blood sugar, blood pH, osmotic pressure, cell membrane potential, etc. is maintained.

Changes in the mechanisms of neurohumoral regulation (see), an increase in the sensitivity of tissues to the action of hormones and mediators against the background of weakening nervous influences are of significant importance in preserving G. in the process of aging of the body.

With the aging of the body, the work of the heart, pulmonary ventilation, gas exchange, renal functions, secretion of the digestive glands, the function of the endocrine glands, metabolism, etc. change significantly. These changes can be characterized as homeoresis - a natural trajectory (dynamics) of changes in the intensity of metabolism and physiol. functions with age over time. The significance of the course of age-related changes is very important for characterizing the aging process of a person, determining his biol, age.

In old age and old age, the general potential of adaptive mechanisms decreases. Therefore, in old age, under increased loads, stress, and other situations, the likelihood of failure of adaptation mechanisms and disruption of health increases. Such a decrease in the reliability of G.’s mechanisms is one of the most important prerequisites for the development of patol and disorders in old age.

Bibliography: Adolf E. Development of physiological regulations, trans. from English, M., 1971, bibliogr.; Anokhin P.K. Essays on the physiology of functional systems, M., 1975, bibliogr.; In e l t i-sh e in Yu. E., Samsygina G, A. and Ermakova I. A. On the characteristics of the osmoregulatory function of the kidneys in children of the newborn period, Pediatrics, No. 5, p. 46, 1975; Gellhorn E. Regulatory functions of the autonomic nervous system, trans. from English, M., 1948, bibliogr.; GlensdorfP. and Prigogine. Thermodynamic theory of structure" stability and fluctuations, trans. from English, M., 1973, bibliogr.; Homeostasis, ed. P. D. Gorizontova, M., 1976; Respiratory function of fetal blood in the obstetric clinic, ed. L. S. Persianinova et al., M., 1971; Kassil G.N. The problem of homeostasis in physiology and clinic, Vestn. Academy of Medical Sciences of the USSR, No. 7, p. 64, 1966, bibliogr.; Rozanova V.D. Essays on experimental age pharmacology, L., 1968, bibliogr.; F r about l-k and with V. V. Regulation, adaptation and aging, JI., 1970, bibliogr.; Stern L. S. Direct nutrient medium of organs and tissues, M., 1960; CannonW. B. Organization for physiological homeostasis, Physiol. Rev., v. 9, p. 399, 1929; Homeostatic regulators, ed. by G, E. W. Wolstenholme a. J. Knight, L., 1969; Langley L. L. Homeostasis, Stroudsburg, 1973.

G. N. Kassil; Yu. E. Veltishchev (ped.), B. N. Tarusov (biofiz.), V. V. Frolkis (ger.).

The concept was introduced by the American psychologist W.B. Cannon in relation to any processes that change the original state or a series of states, initiating new processes aimed at restoring the original conditions. A mechanical homeostat is a thermostat. The term is used in physiological psychology to describe a number of complex mechanisms operating in the autonomic nervous system to regulate factors such as body temperature, bio chemical composition, blood pressure, water balance, metabolism, etc. for example, a change in body temperature initiates a variety of processes such as shivering, increased metabolism, increasing or maintaining heat until normal temperature is reached. Examples of psychological theories of a homeostatic nature are the theory of balance (Heider, 1983), the theory of congruence (Osgood, Tannenbaum, 1955), the theory of cognitive dissonance (Festinger, 1957), the theory of symmetry (Newcomb, 1953), etc. As an alternative to the homeostatic approach, a heterostatic approach is proposed an approach that assumes the fundamental possibility of the existence of equilibrium states within a single whole (see heterostasis).

HOMEOSTASIS

Homeostasis) - maintaining balance between opposing mechanisms or systems; the basic principle of physiology, which should also be considered the basic law of mental behavior.

HOMEOSTASIS

homeostasis) The tendency of organisms to maintain their constant state. According to Cannon (1932), the originator of the term: "Organisms, composed of matter characterized by the highest degree of impermanence and instability, have somehow mastered methods of maintaining constancy and maintaining stability under conditions which should reasonably be regarded as absolutely destructive." Freud's PRINCIPLE OF PLEASURE - DISPLEASURE and Fechner's PRINCIPLE OF CONSTANCE that he used are usually considered as psychological concepts similar to the physiological concept of homeostasis, i.e. they presuppose a programmed tendency to maintain psychological TENSION at a constant optimal level, similar to the body's tendency to maintain constant blood chemistry, temperature, etc.

HOMEOSTASIS

a mobile equilibrium state of a certain system, maintained by its counteraction to external and internal factors that disturb the equilibrium. Maintaining the constancy of various physiological parameters of the body. The concept of homeostasis was originally developed in physiology to explain the constancy of the internal environment of the body and the stability of its basic physiological functions. This idea was developed by the American physiologist W. Cannon in the doctrine of the wisdom of the body as an open system that continuously maintains stability. Receiving signals about changes that threaten the system, the body turns on devices that continue to work until it can be returned to an equilibrium state, to the previous parameter values. The principle of homeostasis moved from physiology to cybernetics and other sciences, including psychology, gaining more general meaning principle systematic approach and self-regulation based on feedback. The idea that every system strives to maintain stability was transferred to the interaction of the organism with the environment. This transfer is typical, in particular:

1) for neo-behaviorism, which believes that a new motor reaction is consolidated due to the liberation of the body from the need that disrupted its homeostasis;

2) for the concept of J. Piaget, which believes that mental development occurs in the process of balancing the organism with the environment;

3) for the field theory of K. Lewin, according to which motivation arises in a nonequilibrium “system of stresses”;

4) for Gestalt psychology, which notes that when the balance of a component of the mental system is disturbed, it strives to restore it. However, the principle of homeostasis, while explaining the phenomenon of self-regulation, cannot reveal the source of changes in the psyche and its activity.

HOMEOSTASIS

Greek homeios - similar, similar, statis - standing, immobility). A mobile but stable equilibrium of any system (biological, mental), due to its resistance to internal and external factors that disrupt this balance (see Cannon’s thalamic theory of emotions. The principle of G. is widely used in physiology, cybernetics, psychology, it explains adaptive ability The body's mental health maintains optimal conditions for the functioning of the brain and nervous system in the process of life.

HOMEOSTASIS(IS)

from Greek homoios - similar + stasis - standing; letters, meaning "to be in the same state").

1. In the narrow (physiological) sense, G. is the process of maintaining the relative constancy of the main characteristics of the internal environment of the body (for example, constancy of body temperature, blood pressure, blood sugar level, etc.) in a wide range of environmental conditions. An important role in G. is played by the joint activity of the vegetative system. s, hypothalamus and brain stem, as well as the endocrine system, with partly neurohumoral regulation of G. It is carried out “autonomously” from the psyche and behavior. The hypothalamus “decides” in case of which G. violation it is necessary to turn to higher forms of adaptation and trigger the mechanism of biological motivation of behavior (see Drive reduction hypothesis, Needs).

The term "G." introduced by Amer. physiologist Walter Cannon (Cannon, 1871-1945) in 1929, however, the concept of the internal environment and the concept of its constancy were developed much earlier than the French. physiologist Claude Bernard (Bernard, 1813-1878).

2. In a broad sense, the concept of "G." apply to the most different systems(biocenoses, populations, individuals, social systems, etc.). (B.M.)

Homeostasis

homeostasis) Complex organisms, in order to survive and move freely in changing and often hostile environmental conditions, need to maintain their internal environment relatively constant. This inner consistency was called "G" by Walter B. Cannon. Cannon described his findings as examples of the maintenance of stable states in open systems. In 1926, he proposed the term "G" for such a stable state. and proposed a system of postulates concerning its nature, which was subsequently expanded in preparation for the publication of a review of homeostatic and regulatory mechanisms known at that time. The body, Cannon argued, through homeostatic reactions is able to maintain the stability of the intercellular fluid (fluid matrix), controlling and regulating it. body temperature, blood pressure and other parameters of the internal environment, maintaining which within certain limits is necessary for life. G. tj is maintained in relation to the levels of supply of substances necessary for the normal functioning of cells. The concept of G. proposed by Cannon appeared in the form of a set of provisions concerning the existence, nature and principles of self-regulating systems. He emphasized that complex living beings are open systems formed from changing and unstable components, constantly exposed to disturbing external influences due to this openness. Thus, these systems, constantly striving for change, must nevertheless maintain constancy relative to the environment in order to maintain conditions favorable to life. Correction in such systems must occur continuously. Therefore, G. characterizes a relatively rather than an absolutely stable state. The concept of an open system challenged all traditional ideas about an adequate unit of analysis for the organism. If the heart, lungs, kidneys and blood, for example, are parts of a self-regulating system, then their action or functions cannot be understood by studying each of them separately. Full understanding is only possible through knowledge of how each of these parts operates in conjunction with the others. The concept of an open system also challenges all traditional views of causation, proposing complex reciprocal determination instead of simple sequential or linear causation. Thus, G. became new perspective both for considering the behavior of various types of systems, and for understanding people as elements of open systems. See also Adaptation, General adaptation syndrome, General systems, Lens model, The question of the relationship between soul and body R. Enfield

HOMEOSTASIS

the general principle of self-regulation of living organisms, formulated by Cannon in 1926. Perls strongly emphasizes the importance of this concept in his work, The Gestalt Approach and Eye Witness to Therapy, begun in 1950, completed in 1970, and published after his death in 1973.

Homeostasis

The process by which the body maintains balance in its internal physiological environment. Through homeostatic impulses, the urge to eat, drink and regulate body temperature occurs. For example, a decrease in body temperature initiates many processes (such as shivering) that help restore normal temperature. Thus, homeostasis initiates other processes that act as regulators and restore the optimal state. As an analogy we can cite central system heating with thermostatic control. When the room temperature drops below the values ​​set in the thermostat, it turns on the steam boiler, which pumps hot water into the heating system, increasing the temperature. When the room temperature reaches normal levels, the thermostat turns off the steam boiler.

HOMEOSTASIS

homeostasis) is a physiological process of maintaining the constancy of the internal environment of the body (ed.), in which various parameters of the body (for example, blood pressure, body temperature, acid-base balance) are maintained in balance, despite changing environmental conditions. - Homeostatic.

Homeostasis

Word formation. Comes from the Greek. homoios - similar + stasis - immobility.

Specificity. The process through which relative constancy of the internal environment of the body is achieved (constancy of body temperature, blood pressure, blood sugar concentration). Neuropsychic homeostasis can be identified as a separate mechanism, which ensures the preservation and maintenance optimal conditions functioning of the nervous system in the process of implementation various forms activities.

HOMEOSTASIS

Literally translated from Greek it means the same state. American physiologist W.B. Cannon coined the term to refer to any process that changes existing condition or a set of circumstances and, as a result, initiates other processes that perform regulatory functions and restore the original state. The thermostat is a mechanical homeostat. This term is used in physiological psychology to refer to a number of complex biological mechanisms that operate through the autonomic nervous system, regulating factors such as body temperature, body fluids and their physical and chemical properties, blood pressure, water balance, metabolism, etc. For example, a decrease in body temperature initiates a series of processes such as shivering, piloerection, and increased metabolism, which cause and maintain a high temperature until normal temperature is reached.

HOMEOSTASIS

from Greek homoios – similar + stasis – state, immobility) – a type of dynamic equilibrium characteristic of complex self-regulating systems and consisting in maintaining parameters essential for the system within acceptable limits. The term "G." proposed by the American physiologist W. Cannon in 1929 to describe the state of the human body, animals and plants. Then this concept became widespread in cybernetics, psychology, sociology, etc. The study of homeostatic processes involves identifying: 1) parameters, significant changes in which disrupt the normal functioning of the system; 2) the limits of permissible changes in these parameters under the influence of external and internal environmental conditions; 3) a set of specific mechanisms that begin to function when the values ​​of variables go beyond these boundaries (B. G. Yudin, 2001). Each conflict reaction of any of the parties when a conflict arises and develops is nothing more than the desire to preserve their G. The parameter, the change of which triggers the conflict mechanism, is the damage predicted as a consequence of the opponent’s actions. The dynamics of the conflict and the rate of its escalation are regulated by feedback: reactions of one side of the conflict to the actions of the other side. Over the past 20 years, Russia has been developing as a system with lost, blocked or extremely weakened feedback connections. Therefore, the behavior of the state and society in the conflicts of this period, which destroyed the country’s civil society, is irrational. The application of G.'s theory to the analysis and regulation of social conflicts can significantly increase the effectiveness of the work of domestic conflictologists.

Homeostasis is the ability of the human body to adapt to changing conditions of the external and internal environment. The stable operation of homeostasis processes guarantees a person a comfortable state of health in any situation, maintaining the constancy of the body’s vital indicators.

Homeostasis from a biological and ecological point of view

Homeostasis applies to any multicellular organisms. At the same time, ecologists often pay attention to the balance of the external environment. It is believed that this is the homeostasis of the ecosystem, which also undergoes changes and is constantly rebuilt for continued existence.

If the balance in any system is disturbed and it is not able to restore it, then this leads to a complete cessation of functioning.

Man is no exception; homeostatic mechanisms play vital role in daily life, and the permissible degree of change in the basic indicators of the human body is very small. With unusual fluctuations in the external or internal environment, a failure in homeostasis can lead to fatal consequences.

Why is homeostasis needed and its types?

Every day a person is exposed to various environmental factors, but in order for the main biological processes in the body continued to work stably, their conditions should not change. It is in maintaining this stability that the main role of homeostasis lies.

It is customary to distinguish three main types:

1. Genetic.
2. Physiological.
3. Structural (regenerative or cellular).

For a full-fledged existence, a person needs the work of all three types of homeostasis in combination; if one of them fails, this leads to unpleasant consequences for health. Coordinated work of processes will allow you not to notice or endure the most common changes with minimal inconvenience and feel confident.

This type of homeostasis is the ability to maintain a single genotype within one population. At the molecular-cellular level, a single genetic system is maintained, which carries a certain set of hereditary information.

The mechanism allows individuals to interbreed with each other, while maintaining the balance and uniformity of a conditionally closed group of people (population).

Physiological homeostasis

This type homeostasis is responsible for maintaining the main vital signs in an optimal state:

• Body temperatures.
• Blood pressure.
• Digestive stability.

The immune, endocrine and nervous system. In the event of an unexpected malfunction in the operation of one of the systems, this immediately affects the well-being of the entire body, leading to a weakening of protective functions and the development of diseases.

Cellular homeostasis (structural)

This type is also called "regenerative", which probably best describes the functional features.

The main forces of such homeostasis are aimed at restoring and healing damaged cells of the internal organs of the human body. It is these mechanisms, when working properly, that allow the body to recover from illness or injury.

The basic mechanisms of homeostasis develop and evolve along with a person, better adapting to changes in the external environment.

Functions of homeostasis

In order to correctly understand the functions and properties of homeostasis, it is best to consider its action using specific examples.

For example, when playing sports, human breathing and heart rate increase, which indicates the body’s desire to maintain internal balance under changed environmental conditions.

When moving to a country with a climate significantly different from your usual one, you may feel unwell for some time. Depending on the general health human, homeostasis mechanisms allow adaptation to new living conditions. Some people do not feel acclimatization and the internal balance quickly adjusts, while others have to wait a little before the body adjusts its parameters.

In conditions of elevated temperature, a person becomes hot and sweats. This phenomenon is considered direct evidence of the functioning of self-regulation mechanisms.

In many ways, the work of basic homeostatic functions depends on heredity, genetic material passed on from the older generation of the family.

Based on the examples given, the main functions can be clearly seen:

• Energy.
• Adaptive.
• Reproductive.

It is important to pay attention to the fact that in old age, as well as in infancy, the stable functioning of homeostasis requires special attention, due to the fact that the reaction of the main regulatory systems is slow during these periods of life.

Properties of homeostasis

Knowing about the main functions of self-regulation, it is also useful to understand what properties it has. Homeostasis is a complex interrelation of processes and reactions. Among the properties of homeostasis are:

• Instability.
• Striving for balance.
• Unpredictability.

The mechanisms are in constant change, testing conditions in order to choose the best option for adapting to them. This shows the property of instability.

Balance is the main goal and property of any organism; it constantly strives for it, both structurally and functionally.

In some cases, the body's reaction to changes in the external or internal environment may become unexpected and lead to restructuring of vital systems. The unpredictability of homeostasis can cause some discomfort, which does not indicate a further detrimental effect on the state of the body.

How to improve the functioning of the mechanisms of the homeostatic system

From a medical point of view, any disease is evidence of a malfunction in homeostasis. External and internal threats constantly impact the body, and only coherence in the operation of the main systems will help cope with them.

Weakening of the immune system does not occur without reason. Modern medicine has a wide range of tools that can help a person maintain their health, regardless of what caused the failure.

Changing weather conditions, stressful situations, injuries - all this can lead to the development of diseases of varying severity.

In order for the functions of homeostasis to work correctly and as quickly as possible, it is necessary to monitor the general state of your health. To do this, you can consult a doctor for an examination to identify your vulnerabilities and choose a set of therapy to eliminate them. Regular diagnostics will help to better control the basic processes of life.

It is important to follow these simple recommendations yourself:

• Avoid stressful situations to protect the nervous system from constant overstrain.
• Monitor your diet, do not overload yourself with heavy foods, and avoid pointless fasting, which will allow the digestive system to cope with its work more easily.
• Select suitable ones vitamin complexes to reduce the impact of seasonal weather changes.

A vigilant attitude towards your own health will help homeostatic processes respond promptly and correctly to any changes.

Homeostasis is a self-regulating process in which all biological systems strive to maintain stability during the period of adaptation to certain conditions that are optimal for survival. Any system, being in dynamic equilibrium, strives to achieve a stable state that resists external factors and stimuli.

The concept of homeostasis

All body systems must work together to maintain proper homeostasis within the body. Homeostasis is the regulation of indicators in the body such as temperature, water content and carbon dioxide levels. For example, diabetes is a condition in which the body is unable to regulate blood glucose levels.

Homeostasis is a term that is used to both describe the existence of organisms in an ecosystem and to describe the successful functioning of cells within an organism. Organisms and populations can maintain homeostasis by maintaining stable levels of fertility and mortality.

Feedback

Feedback is a process that occurs when the body's systems need to be slowed down or stopped completely. When a person eats, food enters the stomach and digestion begins. The stomach should not work in between meals. The digestive system works with a series of hormones and nerve impulses to stop and start the production of acid secretion in the stomach.

Another example of negative feedback can be observed in the case of increased body temperature. Regulation of homeostasis is manifested by sweating, the body’s protective reaction to overheating. Thus, the temperature rise stops and the problem of overheating is neutralized. In case of hypothermia, the body also provides a number of measures taken in order to warm up.

Maintaining internal balance

Homeostasis can be defined as a property of an organism or system that helps it maintain given parameters within a normal range of values. This is the key to life, and not the right balance in maintaining homeostasis can lead to diseases such as hypertension and diabetes.

Homeostasis is a key element in understanding how the human body works. This formal definition characterizes a system that regulates its internal environment and strives to maintain the stability and regularity of all processes occurring in the body.

Homeostatic regulation: body temperature

Controlling a person's body temperature is good example homeostasis in a biological system. When a person is healthy, his body temperature fluctuates around + 37°C, but various factors may affect this value, including hormones, metabolic rate and various diseases, causing an increase in temperature.

In the body, temperature regulation is controlled in a part of the brain called the hypothalamus. Through the bloodstream, signals about temperature indicators are received to the brain, as well as the results of data on respiratory rate, blood sugar levels and metabolism are analyzed. Loss of heat in the human body also contributes to decreased activity.

Water-salt balance

No matter how much water a person drinks, the body does not bloat like balloon, also the human body does not shrink like raisins if you drink very little. Probably someone has thought about this at least once. One way or another, the body knows how much fluid needs to be retained to maintain the desired level.

The concentration of salt and glucose (sugar) in the body is maintained at a constant level (in the absence of negative factors), the amount of blood in the body is about 5 liters.

Regulating Blood Sugar Levels

Glucose is a type of sugar found in the blood. The human body must maintain proper glucose levels in order for a person to remain healthy. When glucose levels become too high, the pancreas produces the hormone insulin.

If blood glucose levels drop too low, the liver converts glycogen in the blood, thereby increasing sugar levels. When pathogenic bacteria or viruses enter the body, it begins to fight the infection before the pathogenic elements can lead to any health problems.

Blood pressure under control

Maintaining healthy blood pressure is also an example of homeostasis. The heart can sense changes in blood pressure and send signals to the brain for processing. The brain then sends a signal back to the heart with instructions on how to respond correctly. If your blood pressure is too high, it needs to be lowered.

How is homeostasis achieved?

How does the human body regulate all systems and organs and compensate for changes in the environment? This occurs due to the presence of many natural sensors that monitor temperature, salt composition of the blood, arterial pressure and many other parameters. These detectors send signals to the brain, main center control in case some values ​​deviate from the norm. After this, compensatory measures are launched to restore the normal state.

Maintaining homeostasis is incredibly important for the body. The human body contains a certain amount of chemicals known as acids and alkalis, the correct balance of which is necessary for the optimal functioning of all organs and systems of the body. The level of calcium in the blood must be maintained at the proper level. Since breathing is involuntary, the nervous system ensures that the body receives much-needed oxygen. When toxins enter your bloodstream, they disrupt the body's homeostasis. The human body responds to this disorder through the urinary system.

It is important to emphasize that the body's homeostasis works automatically if the system is functioning normally. For example, a reaction to heat - the skin turns red because its small blood vessels automatically dilate. Shivering is a response to cooling. Thus, homeostasis is not a collection of organs, but a synthesis and balance of bodily functions. Together, this allows you to maintain the entire body in a stable state.