Adaptive changes in the cardiovascular system. The heart, adapted to physical activity, has a high contractility. But it retains a high ability to relax in diastole at a high frequency of contractions, which is due to an improvement in the processes of regulation of metabolism in the myocardium and a corresponding increase in its mass (cardiac hypertrophy).

Hypertrophy is a normal morphological phenomenon of increased contractile activity (hyperfunction) of the heart. If the density of the capillary bed per unit mass of the heart increases or remains at the level characteristic of the normal myocardium, hypertrophy occurs within the normal physiological limits. The heart muscle does not lack oxygen during hard work. Moreover, the functional load per unit of cardiac mass falls. Consequently, heavy physical activity will be carried by the heart with less functional stress.

The depletion of energy sources during strenuous exercise stimulates the synthesis of protein structures of cellular elements: both contractile and energy (mitochondrial). If the depletion of energy sources exceeds physiological norms, overstrain and adaptation failure may occur. In a normally developed heart, 2300 capillaries are opened per 1 mm3 of muscle mass at rest. During muscular work, an additional 2000 capillaries are opened. Long-term adaptation is ensured by an increase in biosynthetic processes in the heart muscle and an increase in its mass. With periodic physical exertion, the adaptation of the heart is stretched in time, periods of rest from stress lead to a balanced increase in the structural elements of the heart. The mass of the heart increases within 20-40%. The capillary network grows in proportion to the increasing mass. A trained, moderately hypertrophied heart under conditions of relative physiological rest has a reduced metabolism, moderate bradycardia, and a reduced minute volume. It works 15-20% more economically than untrained. With systematic muscular work in the cardiac muscle of a trained heart, the rate of glycolytic processes decreases: energy products are consumed more economically. Morphological rearrangements of the heart are manifested in an increase in both muscle mass and cellular energy machines - mitochondria. The mass of membrane systems also increases. In other words, the sensitivity of the heart to sympathetic influences that enhance its functions increases during muscular work. At the same time, economization mechanisms are also being improved: at rest and with a low-intensity load, the heart works with low energy costs and the most rational ratio of contraction phases.

If the contractile mass of the heart increases by 20-40%, then the functional load per unit of mass decreases by the corresponding amount. This is one of the most reliable and effective mechanisms for preserving the potential resources of the heart.

An increase in heart rate and contractility of the heart are natural adaptive responses to exercise. It is no coincidence that heart rate retains its significance as an indicator of heart adaptation when using any of the most modern functional tests with physical activity. Muscular work requires an increased supply of oxygen and substrates to the muscles. This is provided by an increased volume of blood flow through the working muscles. Therefore, an increase in the minute volume of blood flow during work is one of the most reliable mechanisms for urgent adaptation to a dynamic load. In an untrained adult heart, the reserves for increasing the stroke volume of blood are already exhausted at a heart rate of 120-130 beats / min. Further growth of minute volume occurs only due to heart rate. As training increases, the heart rate range expands, within which the stroke volume continues to increase. In highly trained athletes and children, it continues to grow even with a heart rate of 150-160 beats / min.

In the heart muscle itself, urgent adaptive changes are manifested in the mobilization of energy resources. The primary substrates for oxidation in the heart muscle are fatty acids, glucose, and, to a lesser extent, amino acids. The energy of their oxidation is accumulated by mitochondria in the form of ATP, and then transported to the contractile elements of the heart. With an increase in stroke volume, heart contractions become more frequent. This is due to more effective use the energy of ATP. An increase in the contractility of the heart is combined with the improvement of recovery processes during diastole.

Adaptive changes in the external respiration system. Muscular work causes a multiple (15-20 times) increase in the volume of pulmonary ventilation. In athletes who train mainly for endurance, the minute volume of pulmonary ventilation reaches 130-150 l/min and more. In untrained people, an increase in pulmonary ventilation during work. It is the result of increased breathing. In athletes, with a high respiratory rate, the depth of breathing also increases. This is the most rational way to urgently adapt respiratory apparatus to the load. The achievement of the limiting values ​​of pulmonary ventilation, which is typical for highly qualified athletes, is the result of a high coordination of acts with the contraction of the respiratory muscles, as well as with movements in space and time: a disorder in the coordination of the work of the respiratory muscles disrupts the rhythm of breathing and leads to a deterioration in pulmonary ventilation.

The decisive role in the increase in the volume of pulmonary ventilation at the beginning of work belongs to neurogenic mechanisms. Impulses from contracting skeletal muscles, as well as descending nerve impulses from the motor areas of the cerebral cortex, stimulate the respiratory center. Humoral regulatory factors are switched on later, with continued work and the achievement of adequate lung ventilation values. The regulatory role of CO2 is manifested in maintaining the required respiratory rate and establishing the necessary compliance of pulmonary ventilation with the value physical activity. Systematic muscular activity is accompanied by an increase in the strength of the respiratory muscles. The power of respiratory movements is clearly increasing.

Adaptive changes in the blood system:

The primary response of the blood system to physical activity is changes in the composition of blood cells. The most distinct shifts in the so-called white blood - leukocytes. Myogenic leukocytosis is characterized by a predominant increase in granular leukocytes in the general circulation. At the same time, some of the leukocytes are destroyed: during strenuous physical activity, the number of eosinophils sharply decreases. The structural material formed during their decay goes to plastic needs, to the restoration and biosynthesis of cellular structures.

Physical activity associated with emotional stress causes more significant changes in the composition of the blood. An increase in the number of erythrocytes in the blood is a reliable tool for increasing resistance to muscle hypoxia. The normal leukocyte formula after physical exertion is restored, as a rule, within a day. The so-called red blood system recovers more slowly: after 24 hours of rest, both an increased number of erythrocytes and their immature forms, reticulocytes, remain. In athletes 16-18 years old, after intense muscular work, immature forms of platelets also appear. As a result of muscle activity, the blood coagulation system is activated. This is one of the manifestations of the urgent adaptation of the body to the effects of physical activity. In the process of active motor activity, injuries with subsequent bleeding are possible. By programming such a situation “in advance”, the body increases the protective function of the blood coagulation system. This is a kind of adaptation for the future, in case of damage during muscular work. Recovery of the blood coagulation system occurs within 24-36 hours after exercise.

The role of the hypothalamic-pituitary-adrenal system in the process of adaptation. Structural changes at the cellular and organ levels during physical exertion begin with the mobilization of the endocrine function, and in the first

turn - the hormonal system hypothalamus - pituitary gland - adrenal glands. Schematically, it looks like this. The hypothalamus converts the nerve signal of a real or upcoming physical activity into an efferent, control, hormonal signal. In the hypothalamus, hormones are released that activate the hormonal function of the pituitary gland. Corticoliberin plays a leading role in the development of adaptive responses among these hormones. Under its influence, pituitary adrenocorticotropic hormone (ACTH) is released, which causes the mobilization of the adrenal glands. Adrenal hormones increase the body's resistance to physical stress. Under normal conditions of the body's vital activity, the level of ACTH in the blood also serves as a regulator of its secretion by the pituitary gland. With an increase in the content of ACTH in the blood, its secretion is automatically inhibited. But during strenuous physical activity, the automatic regulation system changes. The interests of the body during the period of adaptation require an intensive function of the adrenal glands, which is stimulated by an increase in the concentration of ACTH in the blood.

Adaptation to physical activity is accompanied by structural changes in the tissues of the adrenal glands. These changes lead to increased synthesis of corticoid hormones. The glucocorticoid series of hormones activates enzymes that accelerate the formation of pyruvic acid and its use as an energy material in the oxidative cycle. At the same time, the processes of glycogen resynthesis in the liver are also stimulated. Glucocorticoids also increase energy processes in the cell, release biologically active substances that stimulate.

When studying the changes occurring in the body under the influence of a combination of environmental (natural and anthropogenic) factors, the term "adaptation" is used. Adaptation is understood as all types of innate and acquired adaptive activities that are provided by physiological reactions that occur at the cellular, organ, system and organism levels. This chapter discusses approaches to the study of adaptation, evolution and forms of adaptation, adaptation theories, adaptogenic factors, adaptation mechanisms.

Approaches to the study of adaptation

When studying adaptation, systemic and individual approaches are used.

Systems approach to adaptation (Fig. 2-1) suggests the need to study adaptation both as a process and as a state of the system, which is characterized by a mobile equilibrium that maintains the stability of structures only with the continuous movement of all components of the system. As a result, balancing with the environment occurs due to the acquisition of a new systemic quality.

Rice. 2-1.Systemic nature of adaptive changes

Individual approach to human adaptation can be characterized as a set of socio-biological properties and characteristics necessary for the sustainable existence of an individual in a particular ecological habitat. In other words, for any organism there is an optimal endogenous (internal) and exogenous (external) ecological environment, and the habitat not only with the optimal characteristics of physical conditions, but also with specific production and social conditions. On both sides of the optimum, labor and biological activity gradually decrease until, finally, conditions become such that the organism cannot exist at all.

Evolution and forms of adaptation

Adaptation is closely related to the evolution of organisms, and stably adapted are those that have adapted to changed conditions, reproduce and give viable offspring in a new habitat. There are two fundamentally different forms of adaptation: genotypic and phenotypic.

Genotypic adaptation, as a result of which modern animal species were formed on the basis of heredity, mutations and natural selection.

Phenotypic adaptation is formed in the process of interaction of a particular organism with its environment.

Structural traces of adaptation are of great biological importance, as they protect a person from future encounters with inadequate and dangerous environmental factors. At the same time, the results of phenotypic adaptation are not inherited, which should be considered beneficial for the conservation of the species, since the next generation adapts anew to a wide range of sometimes completely new factors that require the development of new specialized reactions.

Types of adaptive behavior. There are three types of adaptive behavior of living organisms in response to the action of an unfavorable stimulus: flight from an unfavorable stimulus, passive submission to the stimulus, or active resistance due to the development of specific adaptive reactions.

Homeostasis and homeokinesis. The life support system of the body, along with the mechanisms for maintaining balance internal environment

(homeostasis), is also represented by genetic development programs, the implementation of which is impossible without constant change this internal environment (homeokinesis), realized through diverse adaptive processes (reactions, mechanisms, responses, etc.). The activities of the reproductive, energy and adaptive homeostat systems are aimed precisely at maintaining genetic development programs, which are the leading driving force in a living organism (Fig. 2-2). The optimal functioning of the systems that provide the three leading homeostat is realized through intermediary systems (blood circulation, respiration, blood) and regulatory mechanisms of the autonomic and endocrine systems.

Rice. 2-2.Ensuring the activity of the main homeostatic systems

In other words, adaptation is understood as all types of innate and acquired adaptive activity, which are provided by certain physiological reactions occurring at the cellular, organ, systemic and organism levels. This universal definition of adaptation reflects the need to observe in the living world the fundamental law of biology, formulated by Claude Bernard, the law of the constancy of the internal environment.

Theories of adaptation

During the formation of an adaptive homeostat, the physiological processes that ensure adaptation unfold in stages. For example, V.P. Treasurers subdivide the process of adaptation during relocations into sequentially occurring phases: initial, stabilization, transitional and exhaustion.

The 1st phase - the initial one - is characterized by destabilization of body functions. It can provide adaptation to the action of inadequate factors only for a short period of time, lasting, as a rule, no more than one year. In a number of cases, the phenomena of destabilization characteristic of the first phase of adaptation remain for many years, which, in particular, is one of the reasons for the return of migrants to their former place of residence.

Phase 2 - stabilization - lasts from 1 to 4 years. During this period, synchronization of all homeostatic processes is observed, accompanied not only by functional, but also by structural restructuring of the biosystem.

3rd phase - transitional, lasting from 4 to 5-10 years. At this time, the majority of migrants stabilize their somatic and vegetative functions.

4th phase - exhaustion, possible during long-term residence in the North, is a consequence of overstrain in the homeostatic systems of the body with a lack of genetically programmed mechanisms for long-term adaptation to disturbing environmental factors.

In a generalized form, the considered physiological processes at the organismal level are contained in the experimentally substantiated theory of the "general adaptation syndrome", or stress response (Hans Selye, 1936).

Stress- a complex of nonspecific reactions of the body in response to the action of strong or superstrong stimuli.

Stress in the classical interpretation proceeds in three stages (Fig. 2-3), or phases, namely “anxiety”, transitional, stable adaptation.

The first phase - "anxiety" - develops at the very beginning of the action of both physiological and pathogenic factors or changed environmental conditions. At the same time, visceral systems (circulation, respiration) react, the reactions of which are controlled by the central nervous system with a wide involvement of hormonal factors (in particular, hormones of the adrenal medulla - glucocorticoids and catecholamines), which in turn is accompanied by an increased tone of the sympathetic department of the autonomic nervous system.

Rice. 2-3.Phases of stress according to G. Selye

transitional phase. Often there is a phase that is transitional to sustainable adaptation. It is characterized by a decrease in the general excitability of the central nervous system, the formation of functional systems that provide control of adaptation to new conditions that have arisen. During this phase, the body's adaptive reactions gradually switch to a deeper tissue level.

The phase of stable adaptation, or resistance. New coordination relationships are formed, purposeful protective reactions are carried out. The pituitary-adrenal system is connected, structures are mobilized, as a result of which the tissues receive increased energy and plastic supply. This stage is actually an adaptation - adaptation - and is characterized by a new level of activity of tissue, cellular, membrane elements, rebuilt due to the temporary activation of auxiliary systems, which at the same time can function almost in the original mode, while tissue processes are activated, providing homeostasis adequate to new conditions. existence.

Despite the cost-effectiveness - switching off "extra" reactions, and, consequently, excessive energy consumption, the switching of the body's reactivity to a new level is carried out at a certain voltage of the control systems. This is tense

This is called the “price of adaptation”. Since this stage is associated with a constant tension of regulatory mechanisms, a restructuring of the ratios of nervous and humoral mechanisms, and the formation of new functional systems, these processes, at an over-threshold intensity of stress factors, can cause the development of the exhaustion stage.

Adaptogenic factors

Selye called the factors, the impact of which leads to adaptation, stress factors. Their other name is extreme factors. Extreme can be not only individual effects on the body, but also changed conditions of existence in general (for example, the movement of a person from the south to the Far North, etc.). In relation to a person, adaptogenic factors can be natural and social, associated with labor activity.

natural factors. In the course of evolutionary development, living organisms have adapted to the action of a wide range of natural stimuli. The action of natural factors that cause the development of adaptive mechanisms is always complex, so we can talk about the action of a group of factors of a particular nature. For example, in the course of evolution, all living organisms first of all adapted to the terrestrial conditions of existence: a certain barometric pressure and gravity, the level of cosmic and thermal radiation, a strictly defined gas composition of the surrounding atmosphere, etc.

social factors. In addition to the fact that the human body is subject to the same natural influences as the animal body, the social conditions of a person’s life, factors associated with his work activity, have generated specific factors to which it is necessary to adapt. Their number grows with the development of civilization. Thus, with the expansion of the habitat, conditions and influences that are completely new for the human body appear. For example, space flights bring new impact complexes. Among them is weightlessness - a state that is absolutely inadequate for any organism. Weightlessness is combined with hypokinesia, changes in the daily routine of life, etc.

Adaptation mechanisms

Adaptation begins to develop against the background of a generalized orienting reaction, activation of a nonspecific, as well as a specific response to a causative factor. Subsequently, temporary and functional systems are formed that provide the body with either “escape” from the active emergency agent, or overcoming its pathogenic effects, or an optimal level of vital activity, despite the continuing influence of this agent, i.e. actual adaptation.

Emergency adaptation phase (anxiety) is to mobilize compensatory, protective and adaptive mechanisms. This is manifested by a triad of regular changes - activation, hyperfunction, mobilization.

Activation of the "exploratory" behavioral activity of the individual, aimed at obtaining maximum information about the emergency factor and the possible consequences of its action.

Hyperfunction of many body systems, but mainly those that directly (specifically) provide adaptation to this factor. These systems (physiological and functional) are called dominant.

Mobilization of organs and physiological systems (cardiovascular, respiratory, blood, systems of immunobiological surveillance, metabolism, etc.), which respond to the impact of any factor that is extraordinary for a given organism.

The development of the emergency phase of adaptation is based on several interrelated mechanisms, the launch of which is carried out as a result of activation under the action of an emergency factor of the autonomic nervous (sympathetic department) and endocrine systems and, as a result, a significant increase in the blood and other body fluids of the so-called stress, activating the function and catabolic processes of hormones and neurotransmitters - adrenaline, norepinephrine, glucagon, gluco- and mineralocorticoids, thyroid hormones.

The biological meaning of the reactions developing in the emergency phase of adaptation (despite their non-specificity, imperfection, high energy and substrate “cost”) is to create the conditions necessary for

the organism "lasted" until the stage of formation of its stable adaptation (resistance) to the action of an extreme factor.

Transition phase of adaptation characterized by a decrease in the excitability of the central nervous system, the formation of functional systems that provide control of adaptation to new conditions. The intensity of hormonal shifts decreases, a number of systems and organs that were initially involved in the reaction are gradually turned off. During this phase, the body's adaptive reactions gradually switch to a deeper - tissue - level. The hormonal background is modified, the hormones of the adrenal cortex - "hormones of adaptation" - enhance their action.

The stage of sustainable or long-term adaptation organism to the action of an emergency factor is realized as follows. Occur:

The formation of a state of specific resistance of the body to both a specific agent that caused adaptation, and often to other factors - cross-adaptation;

Increasing the power and reliability of the functions of organs and dominant physiological systems that provide adaptation to a certain factor. In such systems, there is an increase in the number and / or mass of structural elements (ie hypertrophy and hyperplasia), endocrine glands, effector tissues and organs.

The complex of such changes is designated as a structural trace of the adaptation process. The signs of a stress reaction are eliminated, an effective adaptation of the body to the extraordinary factor that caused the adaptation process is formed. As a result, a reliable and stable adaptation of the body to changing socio-biological environmental conditions is formed. Both previously activated processes and those that are additionally activated are implemented. The latter include reactions that provide predominant energy and plastic supply to the cells of the dominant systems. This is combined with a limitation in the supply of oxygen and metabolic substrates to other body systems and is carried out due to reactions of two categories:

Redistribution of blood flow - increasing it in the tissues and organs of the dominant systems due to a decrease in others;

Activation of the genetic apparatus of long-term hyperfunctioning cells and subsequent hypertrophy and hyperplasia of subcellular structural elements with simultaneous inhibition of gene expression in cells of non-dominant systems and organs (for example, digestion, muscle system, kidneys, etc.).

Disadaptation.In most cases, the process of adaptation ends with the formation of long-term resistance of the organism to the extraordinary factor acting on it. And at the same time, the phase of persistent adaptation is associated with a constant stress on the control and executive structures, which can lead to their exhaustion. Depletion of control mechanisms, on the one hand, and cellular mechanisms associated with increased energy costs, on the other hand, leads to maladaptation.

Unfinished adaptation occurs when the functional reserves of the body are depleted and includes the centralization of control and an increase in the reactivity of the mechanisms of autonomic regulation. The state of incomplete adaptation is characteristic not only of a significant part of people living in extreme climatic and geographical conditions, expeditionary shift workers, but also of the population of megacities of the middle climatic zone, the ecological situation in which is unfavorable.

QUESTIONS FOR SELF-CHECKING

1. Define adaptation.

2. What forms of adaptation do you know?

3. What is the essence of an individual approach to adaptation?

4. What theories of adaptation exist?

5. Name the phases of the general adaptation syndrome.

6. What adaptogenic factors do you know?

7. What is an unfinished adaptation?

Phase character of adaptation
The process of adaptation has a phase character. The first phase, the initial one, is characterized by the fact that under the primary influence of an external, unusual in strength or duration factor, generalized physiological reactions occur that are several times greater than the needs of the body. These reactions proceed uncoordinated, with great tension of organs and systems. Therefore, their functional reserve is soon depleted, and the adaptive effect is low, which indicates the "imperfection" of this form of adaptation. It is believed that adaptive reactions at the initial stage proceed on the basis of ready-made physiological mechanisms. At the same time, homeostasis maintenance programs can be congenital or acquired (during previous individual experience) and can exist at the level of cells, tissues, fixed connections in subcortical formations and, finally, in the cerebral cortex due to its ability to form temporary connections.
An example of the manifestation of the first phase of adaptation can be an increase in pulmonary ventilation and minute blood volume during hypoxic exposure, etc. The intensification of the activity of visceral systems during this period occurs under the influence of neurogenic and humoral factors. Any agent causes activation in the nervous system of the hypothalamic centers. In the hypothalamus, information is switched to efferent pathways that stimulate the sympathoadrenal and pituitary-adrenal systems. As a result, there is an increased release of hormones: adrenaline, norepinephrine and glucocorticoids. At the same time, disturbances in the differentiation of the processes of excitation and inhibition in the hypothalamus that occur at the initial stage of adaptation lead to the disintegration of regulatory mechanisms. This is accompanied by malfunctions in the functioning of the respiratory, cardiovascular and other autonomic systems.
At the cellular level, in the first phase of adaptation, catabolism processes are intensified. Due to this, the flow of energy substrates, oxygen and building material enters the working bodies.
The second phase is transitional to sustainable adaptation. It manifests itself under conditions of strong or prolonged influence of a disturbing factor, or a complex effect. In this case, a situation arises when the existing physiological mechanisms cannot provide proper adaptation to the environment. It is necessary to create a new system that creates new connections based on elements of old programs. Thus, under the action of a lack of oxygen, a functional system is created based on oxygen transport systems.
The main place for the formation of new adaptation programs in humans is the cerebral cortex with the participation of thalamic and hypothalamic structures. The thalamus provides basic information for this. The cerebral cortex due to the ability to integrate information, the formation of temporary connections in the form conditioned reflexes and the presence of a complex socially determined behavioral component shapes this program. The hypothalamus is responsible for the implementation of the autonomic component of the program set by the cortex. He carries out its launch and correction. It should be noted that the newly formed functional system is fragile. It can be "erased" by inhibition caused by the formation of other dominants, or extinguished by non-reinforcement.
Adaptive changes in the second phase affect all levels of the body.
. At the cellular-molecular level, enzymatic shifts mainly occur, which provide the possibility of cell functioning with a wider range of fluctuations in biological constants.
. The dynamics of biochemical reactions can cause changes in the morphological structures of the cell, which determine the nature of its work, for example cell membranes.
. Additional structural-morphological and physiological mechanisms appear at the tissue level. Structural and morphological changes provide the necessary physiological reactions. Thus, in high altitude conditions, an increase in the content of fetal hemoglobin was noted in human erythrocytes.
. At the level of an organ or physiological system, new mechanisms can operate on the principle of substitution. If any function does not maintain homeostasis, it is replaced by a more adequate one. Thus, an increase in pulmonary ventilation during exercise can occur both due to the frequency and due to the depth of breathing. The second option during adaptation is more beneficial for the body. Among the physiological mechanisms, one can cite a change in the indicators of the activity of the central nervous system.
. At the organismic level, either the principle of substitution operates, or additional functions are connected, which expands the functionality of the organism. The latter occurs due to neurohumoral influences on the trophism of organs and tissues.
The third phase is the phase of stable or long-term adaptation. The main condition for the onset of this stage of adaptation is the repeated or prolonged action on the body of factors that mobilize the newly created functional system. The body moves to a new level of functioning. It begins to work in a more economical mode by reducing energy costs for inadequate reactions. At this stage, biochemical processes at the tissue level predominate. Accumulating in cells under the influence of new environmental factors, decay products become stimulants of anabolism reactions. As a result of the restructuring of cellular metabolism, anabolism processes begin to predominate over catabolic ones. There is an active synthesis of ATP from the products of its decay.
Metabolites accelerate the process of RNA transcription on DNA structural genes. An increase in the amount of messenger RNA causes the activation of translation, leading to an intensification of the synthesis of protein molecules. Thus, the enhanced functioning of organs and systems affects the genetic apparatus of the cell nuclei. This leads to the formation of structural changes that increase the power of the systems responsible for adaptation. It is this “structural footprint” that is the basis of long-term adaptation.

Signs of adaptation achievement
In its physiological and biochemical essence, adaptation is a qualitatively new state characterized by an increased resistance of the organism to extreme influences. The main feature of the adapted system is the efficiency of operation, i.e., the rational use of energy. At the level of the whole organism, the manifestation of adaptive restructuring is the improvement of the functioning of nervous and humoral regulatory mechanisms. In the nervous system, the strength and lability of the processes of excitation and inhibition increase, the coordination of nervous processes improves, and interorgan interactions improve. A clearer relationship is established in the activity of the endocrine glands. Strongly act "hormones of adaptation" - glucocorticoids and catecholamines.
An important indicator of the adaptive restructuring of the body is an increase in its protective properties and the ability to carry out rapid and effective mobilization of immune systems. It should be noted that with the same adaptive factors and the same results of adaptation, the body uses individual adaptation strategies.

Evaluation of the effectiveness of adaptation processes
In order to determine the effectiveness of adaptation processes, certain criteria and methods for diagnosing the functional states of the body have been developed. R.M. Bayevsky (1981) proposed to take into account five main criteria: 1. The level of functioning of physiological systems. 2. The degree of tension of regulatory mechanisms. 3. Functional reserve. 4. Degree of compensation. 5. The balance of the elements of the functional system.
Methods for diagnosing functional states are aimed at assessing each of the listed criteria. 1. The level of functioning of individual physiological systems is determined by traditional physiological methods. 2. The degree of tension of regulatory mechanisms is studied: indirectly by methods of mathematical analysis of the heart rhythm, by studying the mineral secretory function of the salivary glands and the daily periodicity of physiological functions. 3. To assess the functional reserve, along with the known functional load tests, the “adaptation price” is studied, which is the lower, the higher the functional reserve. 4. The degree of compensation can be determined by the ratio of specific and non-specific components of the stress response. 5. To assess the balance of the elements of a functional system importance have such mathematical methods as correlation and regression analysis, modeling by state-space methods, and a systematic approach. Currently, measuring and computing systems are being developed that allow for dynamic control over the functional state of the body and prediction of its adaptive capabilities.

Violation of adaptation mechanisms
Violation of the adaptation process is phased:
. First stage- this is a state of functional tension of adaptation mechanisms. Its most characteristic feature is a high level of functioning, which is ensured by intensive or prolonged tension of regulatory systems. Because of this, there is a constant danger of developing deficiency phenomena.
. The later stage of the border zone is a state of unsatisfactory adaptation. It is characterized by a decrease in the level of functioning of the biosystem, a mismatch of its individual elements, the development of fatigue and overwork. The state of unsatisfactory adaptation is an active adaptive process. The organism tries to adapt to the conditions of existence that are excessive for it by changing the functional activity of individual systems and the corresponding tension of regulatory mechanisms (increasing the "payment" for adaptation). However, due to the development of insufficiency, violations extend to energy and metabolic processes, and the optimal mode of functioning cannot be ensured.
. The state of failure of adaptation (breakdown of adaptation mechanisms) can manifest itself in two forms: pre-illness and illness.
. Predisease is characterized by the manifestation of the initial signs of disease. This state contains information about the localization of probable pathological changes. This stage is reversible, since the observed deviations are functional in nature and are not accompanied by significant anatomical and morphological changes.
. The leading symptom of the disease is the limitation of the adaptive capabilities of the organism.
The insufficiency of general adaptive mechanisms in case of illness is complemented by the development of pathological syndromes. The latter are associated with anatomical and morphological changes, which indicates the occurrence of foci of local wear of structures. Despite the specific anatomical and morphological localization, the disease remains a reaction of the whole organism. It is accompanied by the inclusion of compensatory reactions, which are a physiological measure of the body's defense against disease.

Methods for increasing the effectiveness of adaptation
They can be non-specific and specific. Non-specific methods of increasing the effectiveness of adaptation: outdoor activities, hardening, optimal (average) physical activity, adaptogens and therapeutic dosages of various resort factors that can increase non-specific resistance, normalize the activity of the main body systems and thereby increase life expectancy.
Consider the mechanism of action of non-specific methods on the example of adaptogens. Adaptogens are means that carry out pharmacological regulation of the body's adaptive processes, as a result of which the functions of organs and systems are activated, the body's defenses are stimulated, and resistance to adverse external factors increases.
An increase in the efficiency of adaptation can be achieved in various ways: with the help of doping stimulants or tonics.
. Stimulants, excitingly affecting certain structures of the central nervous system, activate metabolic processes in organs and tissues. This intensifies the processes of catabolism. The action of these substances appears quickly, but it is short-lived, as it is accompanied by exhaustion.
. The use of tonics leads to the predominance of anabolic processes, the essence of which lies in the synthesis of structural substances and energy-rich compounds. These substances prevent violations of energy and plastic processes in tissues, as a result, the body's defenses are mobilized and its resistance to extreme factors increases. The mechanism of action of adaptogens: firstly, they can act on extracellular regulatory systems - the central nervous system and the endocrine system, as well as directly interact with cellular receptors different type modulate their sensitivity to the action of neurotransmitters and hormones). Along with this, adaptogens are able to directly affect biomembranes, affecting their structure, the interaction of the main membrane components - proteins and lipids, increasing the stability of membranes, changing their selective permeability and the activity of enzymes associated with them. Adaptogens can, penetrating into the cell, directly activate various intracellular systems. According to their origin, adaptogens can be divided into two groups: natural and synthetic.
Sources of natural adaptogens are terrestrial and aquatic plants, animals and microorganisms. The most important adaptogens of plant origin include ginseng, eleutherococcus, Chinese magnolia vine, Manchurian aralia, zamaniha, etc. A special kind of adaptogens are biostimulants. These are an extract from aloe leaves, juice from Kalanchoe stalks, peloidin, distillates of firth and silt therapeutic mud, peat (distillation of peat), gumizol (solution of humic acid fractions), etc. Animal preparations include: pantocrine obtained from deer antlers ; rantarin - from reindeer antlers, apilak - from royal jelly. Many effective synthetic adaptogens are derived from natural products (oil, coal, etc.). Vitamins have a high adaptogenic activity. Specific methods for increasing the efficiency of adaptation. These methods are based on increasing the body's resistance to any specific environmental factor: cold, high temperature, hypoxia, etc.
Let's consider some specific methods on the example of adaptation to hypoxia.
. The use of adaptation in high altitude conditions to increase the body's adaptive reserves. Staying in the mountains increases the "altitude ceiling", i.e. resistance (resistance) to acute hypoxia. Various types of individual adaptation to hypoxia have been noted, including diametrically opposed ones, ultimately aimed at both economization and hyperfunction of the cardiovascular and respiratory systems.
. The use of various modes of pressure-chamber hypoxic training is one of the most accessible methods for increasing altitude stability. At the same time, it has been proven that the adaptive effects after training in the mountains and in a pressure chamber with the same hypoxic stimulus and equal exposure are very close. V. B. Malkin et al. (1977, 1979, 1981, 1983) proposed a method for accelerated adaptation to hypoxia, which makes it possible to increase altitude resistance in a short time. This method is called express training. It includes multiple stepped pressure chamber rises with “platforms” at various heights and a descent to the “ground”. Such cycles are repeated several times.
. A fundamentally new mode of hypoxic training should be recognized as pressure-chamber adaptation in sleep conditions. The fact that the training effect is formed during sleep is of great theoretical importance. It makes us take a fresh look at the problem of adaptation, the mechanisms of formation of which are traditionally and not always rightfully associated only with the active waking state of the body.
. The use of pharmacological agents for the prevention of mountain sickness, taking into account the fact that in its pathogenesis the leading role belongs to violations of the acid-base balance in the blood and tissues and the associated changes in membrane permeability. Taking drugs that normalize acid-base balance should also eliminate sleep disorders in hypoxic conditions, thereby contributing to the formation of an adaptive effect. Such a drug is diacarb from the class of carbonic anhydrase inhibitors.
. The principle of interval hypoxic breathing training gas mixture, containing from 10 to 15% oxygen, is used to increase the adaptive potential of a person and to increase physical capabilities, as well as to treat various diseases such as radiation sickness, coronary heart disease, angina pectoris, etc.

There are three adaptation mechanisms:

1. passive way of adaptation - according to the type of tolerance, endurance;

2. the adaptive pathway operates at the cellular-tissue level;

3. resistant way - keeps the relative constancy of the internal environment

Specific adaptive mechanisms inherent in a person give him the opportunity to endure a certain range of factor deviations from optimal values ​​without disturbing the normal functions of the body. Zones of quantitative expression of physical activity, deviating from the optimum, but not disrupting life, are defined as normal zones. There are two of them: a deviation towards a lack of dosing of physical activity and towards an excess. A further shift can reduce the effectiveness of adaptive mechanisms and even disrupt the vital activity of the organism. With an extreme lack of load or its excess, pessimum zones are distinguished. Adaptation to any factor is associated with energy costs. In the optimum zone, active mechanisms are not needed, and energy is spent on fundamental life processes, the body is in equilibrium with the environment. When the load increases and goes beyond the optimum, adequate mechanisms are activated.

Mechanisms that ensure the adaptive nature of the general level of stabilization of individual functional systems (i.e., the body's oxygen consumption increases, the intensity of metabolic processes increases. This occurs at the organ level: the blood flow rate increases, blood pressure rises, the respiratory volume of the lungs increases, breathing quickens, breathing becomes more deep) and the body as a whole. General adaptive reactions of the body are non-specific, that is, the body reacts similarly in response to the actions of stimuli of different quality and strength (physical exercises).

Changes at the cellular level, hormonal changes

Adaptive reactions of the body and its resistance in connection with muscle activity.

The organism retains the relative dynamic constancy of the internal environment necessary for life, although it responds to the action of numerous changing external and internal factors. It is the reaction that is the main way of adaptation, adaptation of the living. Each of the acting factors is characterized by quality and quantity. The quality of the stimulus distinguishes this stimulus from many others, determines the specifics of its action. The amount of an irritant, the measure of its biological activity, is something common that is characteristic of any stimulus and determines the non-specific side of its effect on the body.

Muscle loading is no exception. Under muscle load, as well as under the action of any stimulus, a number of specific changes occur in the body and a nonspecific reaction develops, associated with a quantitative measure of the load. Of course, the concepts of "quantity", "measure", "strength", "dose" in relation to the body are very relative. The degree of biological activity of the active factor is determined not only by the absolute value of this factor, but also by the sensitivity of the organism to it.

In relation to muscle load, this is of particular importance, since with the help of training you can control the sensitivity and resistance of the body to it. A well-trained athlete can endure such a muscular load that an untrained athlete would be unbearable. Despite this, everyone will react differently to the load depending on the change in its magnitude, i.e. the quantitative-qualitative principle will remain: the dependence of the body's response on the magnitude of the load.

The nonspecific nature of the adaptive reaction of the whole organism was first shown by G. Selye; any in quality, but strong stimuli caused the development of the same symptom complex in the body. The specific, special effect of the stimulus persisted, but under the action of any strong stimulus, after 6 hours, there was a decrease in the thymus gland, an increase in the adrenal glands, the presence of ulcers and hemorrhages in the mucous membrane of the alimentary canal. Leukocytosis, lymphopenia, aneosinophilia were observed in the blood. Selye called the general non-specific adaptive reaction to a strong stimulus - stress (stress reaction), and its first stage - an anxiety reaction. In the alarm reaction there are elements of damage, oppression with one-sided sharp stimulation of the ACTH axis - glucocorticoid hormones. In response to a strong impact, it is necessary to quickly mobilize the body's energy resources. This is what happens under stress, but in an extremely uneconomical and destructive way for the body. After the anxiety reaction comes the second stage of stress - the stage of resistance. At this stage, nonspecific resistance of the organism increases. If the stressor was excessively strong or its effect is long, then the stage of stress depletion develops. The exhaustion stage can lead to death.

For many years, stress was considered the only adaptive reaction, and, along with its negative features, researchers were increasingly interested in the positive - increased resistance. Increasing the body's resistance, and even non-specific - not to one damaging factor, load, but to different ones - this is necessary in sports. However, the increase in resistance to stress, according to Selye, comes at the cost of damage and high energy expenditure.

Is there another, milder way to increase the body's nonspecific resistance?

N.V. Lazarev believes that there is such a way. With the help of a number of substances called adaptogens, it caused a state of non-specifically increased resistance (SNPS), in which the body's resistance increased without elements of damage. This other way is qualitative: certain substances (adantogens) cause SNPS. It has been established that adaptogens, depending on the dose, can cause both SNPS and other complexes of change, and large doses of adaptogens can even cause stress. It could be assumed that if a general nonspecific adaptive reaction to a strong stimulus developed in evolution, then there must be reactions to weaker, physiological stimuli. Our studies have shown that in addition to stress, there are two more general non-specific adaptive reactions of the body: to weak stimuli - a reaction called the training reaction, to medium (intermediate between strong and weak) - a reaction called the activation reaction.

Thus, a quantitative and qualitative regularity in the development of general non-specific adaptive reactions was discovered: depending on the strength, dose, biological activity of acting factors, external and internal environment, qualitatively different adaptive reactions develop in the body.

Changes in the body during the activation reaction have a character than during stress. Already in stage I, the stage of primary activation, instead of reducing resistance, it increases, instead of reducing the thymus gland - its significant increase with an increase in the functional activity of lymphoid elements in the endocrine system - a harmonious and well-coordinated moderate increase in the secretion of thyroid hormones, sex hormones and cortical substance adrenal glands mainly due to mineralocorticoids, but without a decrease in the level of glucocorticoids. This is due to the predominance in the brain (especially in the hypothalamus, where adaptive reactions are formed) of physiological excitation with good functional activity of neuronal and glial elements. In the stage of persistent activation, which develops with the systematic repetition of activation actions, the increase in resistance becomes persistent. The functional activity of the central nervous system and endocrine glands is quite high, but not excessive. This state of neuroendocrine regulation should create favorable conditions for muscle activity. This is also evidenced by the state of peripheral receptor endings (neuromuscular endings) that provide muscle contractions. If during stress in the neuromuscular endings the number of detectable nerve fibers decreases, and in the remaining nerve fibers and endings there is a pronounced swelling and uneven impregnation with silver, then with the development of the activation reaction, the nerve fibers and endings are well detected, and the impregnation with silver evenly increases in them. This is also indicated by high motor activity and the need for movement, which characterizes the activation reaction and especially the zone of increased activation.

The training reaction got its name because in order to maintain it in the body for a long time, initially weak effects have to be systematically repeated daily, gradually increasing the load, i.e. the principle of any training is used in general terms. This reaction has signs of similarity with the activation reaction and stress, but it is characterized by its own set of changes. In the first stage of the training reaction - the orientation stage - the thymus is not depressed, as in stress, but it is less enlarged than in the activation reaction (the difference is statistically significant). An increase in resistance at this stage occurs due to a decrease in sensitivity: protective inhibition predominates in the brain. The function of the genital organs and the thyroid gland is not suppressed, but their activity is not as high as in the activation reaction. The secretion of glucocorticoids is increased, but not as sharply as during stress; secretion of mineralocorticoids is also increased, although not as significantly as in the activation reaction.

One of the mechanisms of adaptation of the body to the environment is self-regulation - the basis of resistance (resistance) of the organism to influencing factors.

A great contribution to the study of the mechanisms of adaptation of the organism to the environment was made by P.K. Anokhin. He is the creator of the theory of functional systems. Functional system - this is a combination of processes and mechanisms, which, being formed, depending on the given conditions, leads to the effect of adaptation to these conditions. This system is created every time anew, in relation to the influencing factor, is capable of removing the body from an extreme situation in the shortest possible time, most economically and rationally.

The immune system plays an important role in the adaptation of the body. Immunity (lat. immunitas - release, getting rid of something) - the body's immunity to infectious and non-infectious agents and substances with alien antigenic properties.

Immunity is carried out by the immune system of the body, which is a combination of lymphoid organs: central (thymus, sac of Fabricius, bone marrow, lymph follicles) and peripheral (lymph nodes, spleen and immune-component blood cells T- and B-lymphocytes), capable of recognizing foreign substances and forcing specific immune response. There are 30-40 billion lymphocytes circulating in human blood, of which 60% are T-cells, and 40% are B-cells. The function of B-lymphocytes is the production of antibodies. With the help of T-lymphocytes, acting as assistants in antibody formation, B-lymphocytes begin to multiply and turn into plasma cells that actively produce antibodies - specific immunoglobulins, bind and neutralize the antigen as a result of the formation of an antigen-antibody complex, then this complex is destroyed by various non-specific influences and excreted from the body. A number of substances (interferon, lysozyme, properdin, B-lysine, lymphokines) produced by leukocytes and other cells of the body are also involved in providing immunity.

The formation of immune reactions begins in the embryonic period, then throughout a person's life, they carry out a number of complex protective functions, gradually weakening in old age. There are two main types of immunity. These are hereditary (congenital) and acquired (non-hereditary). Allocate innate passive immunity, which is transmitted from mother to child through the placenta. It is unstable, as the developed antibodies die quickly. However, a child under 1 year of age practically does not suffer from infectious diseases. Innate active immunity arises as a result of contact of the organism with an antigen and is not established immediately - after 1-2 weeks or later and persists for a relatively long time - for years or tens of years.

Actively acquired immunity is immunity that is created by vaccination, i.e. administration of attenuated antigens. As a result, antibodies are produced, memory cells are formed. Upon repeated contact with this antigen, the body's resistance increases, i.e. antibodies are quickly formed, and the person does not get sick. Passively acquired immunity is immunity that is created by introducing ready-made antibodies into the body. Depending on the outcome of the infectious process, two forms of acquired immunity are distinguished - sterile and non-sterile.

Immunity can be specific and nonspecific. Specific is called immunity to a particular infection (for example, diphtheria), and non-specific - congenital or acquired resistance to a variety of pathogens. Sometimes specific immunity, actively or passively developed in relation to a certain pathogen, is simultaneously accompanied by the development of nonspecific immunity to another or other pathogens. Along with general immunity, local, tissue immunity is distinguished, meaning by this shifts in the reactivity of individual tissues that occur against the background of general immunity. These shifts are expressed to varying degrees in different tissues.

Adapting the body to change environment due to another very important factor - a large "margin of safety" of the body . The organism is arranged according to the limited limit plan and the principle of the strictest economy. For example, the heart can at any time increase the number of contractions by 2 times, and increase blood pressure by 30-40%. Arterial blood contains about 3.5 times more oxygen than is used by the tissues. Removal of 2/3 of each kidney is tolerated without serious impairment of renal function. It has been established that 1/10 of the adrenal glands is enough to save life. The margin of safety in a living organism is achieved in various ways: the reserve capabilities of the body, changes in metabolism, the inclusion of other body systems, changes in the structure of the cell (hypertrophy, regeneration). In the course of evolution, the economical and beneficial use of energy and matter was improved. The principle of paired organs, the principle of duplication of functions, the detoxic function of the liver, the principle of consistency and self-regulation underlie the adaptation of the body to environmental factors.

An important role in the mechanisms of adaptation is also played by the general adaptation syndrome, the so-called stress response and biological rhythms .

It should be noted that any protective and adaptive organization is a relative concept. The operating factor may make demands above the limit of human adaptive capabilities. The discrepancy between the adaptive capabilities of a person to the influence of environmental factors can be quantitative, when the intensity of the impact is above the permissible limit, or qualitative. For example, the adaptation of the cardiovascular system to hypoxia is manifested in an increase in the minute volume of blood, an increase in blood pressure and heart rate, a redistribution of blood and oxygen flow to the heart, and the release of erythrocytes from the depot.