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Free adaptation to cold. Methodical development. Topic: "Physiological basis of adaptation of the athlete's body to new climatic conditions

Content
I. Introduction

II. Main part

1. Optium and pessium. Temperature efficiency sum

2. Poikilothermic organisms

2.1 Passive stability

2.2 Metabolic rate

2.3 Temperature adaptations

3. Homeothermic organisms

3.1 Body temperature

3.2 Mechanism of thermoregulation

Bibliography
I Introduction
Organisms are real carriers of life, discrete units of metabolism. In the process of metabolism, the body consumes environment necessary substances and releases into it metabolic products that can be used by other organisms; dying, the body also becomes a source of nutrition for certain types of living beings. Thus, the activity of individual organisms underlies the manifestation of life at all levels of its organization.

The study of fundamental metabolic processes in a living organism is the subject of physiology. However, these processes take place in a complex, dynamic environment. natural environment habitats are under the constant influence of a complex of its factors. Maintaining a stable metabolism in fluctuating conditions external environment impossible without special adaptations. The study of these adaptations is the task of ecology.

Adaptations to environmental factors can be based on the structural features of the organism - morphological adaptations - or on specific forms of functional response to external influences - physiological adaptations. In higher animals, an important role in adaptation is played by higher nervous activity, on the basis of which adaptive forms of behavior are formed - ecological adaptations.

In the field of studying adaptations at the level of the organism, the ecologist comes into closest interaction with physiology and applies many physiological methods. However, when applying physiological methods, ecologists use them to solve their specific problems: the ecologist is primarily interested not in the fine structure of the physiological process, but in its final result and the dependence of the process on the impact external factors. In other words, in ecology, physiological indicators serve as criteria for the body's response to external conditions, and physiological processes are considered primarily as a mechanism that ensures the uninterrupted implementation of fundamental physiological functions in a complex and dynamic environment.
II. MAIN PART
1. Optimum and pessimum. Sum of effective temperatures
Any organism is able to live within a certain range of temperatures. The temperature range on the planets of the solar system is equal to thousands of degrees, and the limits. In which life known to us can exist are very narrow - from -200 to + 100 ° С. Most species live in an even narrower temperature range.

Some organisms. Especially in the resting stage, they can exist at very low temperatures Oh, and certain types of microorganisms are able to live and multiply in urban sources at a temperature close to the boiling point. The range of temperature fluctuations in water is usually smaller than on land. The range of tolerance also changes accordingly. Temperature is often associated with zonation and stratification in both water and terrestrial habitats. The degree of temperature variability and its fluctuations are also important, that is, if the temperature varies from 10 to 20 C and the average value is 15 C, this does not mean that the fluctuating temperature has the same effect as the constant one. Many organisms thrive best in conditions of variable temperatures.

Optimal conditions are those under which all physiological processes in the organism or ecosystems proceed with maximum efficiency. For most species, the optimum temperature is within 20-25 ° C, slightly shifting in one direction or another: in the dry tropics it is higher - 25-28 ° C, in temperate and cold zones it is lower - 10-20 ° C. In the course of evolution, adapting not only to periodic temperature changes, but also to regions with different heat supply, plants and animals developed different needs for heat in different periods of life. Each species has its own optimal temperature range, and for different processes (growth, flowering, fruiting, etc.) there are also “their own” optimum values.

It is known that physiological processes in plant tissues begin at a temperature of +5°C and are activated at +10°C and above. In coastal forests, development spring views especially clearly associated with average daily temperatures from -5°С to +5°С. A day or two before the temperature passes through -5 ° C, under the forest floor, the development of the stellate springweed and Amur adonis begins, and during the transition through 0 ° C, the first flowering individuals appear. And already at an average daily temperature of + 5 ° C, both species bloom. Due to the lack of heat, neither adonis nor springweed form a continuous cover, they grow singly, less often - several individuals together. A little later than them - with a difference of 1-3 days, anemones start to grow and bloom.

Temperatures "lying" between lethal and optimal are pessimal. In the zone of pessimism, all life processes are very weak and very slow.

The temperatures at which active physiological processes occur are called effective, their values do not go beyond lethal temperatures. The sum of effective temperatures (ET), or the sum of heat, is a constant value for each species. It is calculated by the formula:
ET = (t - t1) × n,
Where t is the ambient temperature (actual), t1 is the temperature of the lower threshold of development, often 10°C, n is the duration of development in days (hours).

It was revealed that each phase of the development of plants and ectothermic animals occurs at a certain value of this indicator, provided that other factors are at an optimum. Thus, the flowering of coltsfoot occurs at a sum of temperatures of 77 ° C, strawberries - at 500 ° C. The sum of effective temperatures (ET) for the entire life cycle allows you to identify the potential geographic range of any species, as well as to make a retrospective analysis of the distribution of species in the past. For example, the northern limit of woody vegetation, in particular Cajander larch, coincides with the +12°С July isotherm and the sum of ET above 10°С – 600°. For early crops, the sum of ET is 750°, which is quite enough for growing early varieties potatoes even in the Magadan region. And for Korean pine, the sum of ET is 2200°, for whole-leaved fir - about 2600°, therefore both species grow in Primorye, and fir (Abies holophylla) - only in the south of the region.
2. POIKILOTHERM ORGANISMS
Poikilothermic (from the Greek poikilos - changeable, changing) organisms include all taxa of the organic world, except for two classes of vertebrates - birds and mammals. The name emphasizes one of the most noticeable properties of the representatives of this group: instability, their body temperature, which varies widely depending on changes in ambient temperature.

Body temperature . The fundamental feature of heat exchange in poikilothermic organisms is that, due to the relatively low level of metabolism, their main source of energy is external heat. This explains the direct dependence of the body temperature of poikilotherms on the temperature of the environment, more precisely, on the influx of heat from outside, since terrestrial poikilotherms also use radiation heating.

However, a complete correspondence between the temperatures of the body and the environment is rarely observed and is characteristic mainly of organisms of very small sizes. In most cases, there is some discrepancy between these indicators. In the range of low and moderate environmental temperatures, the body temperature of organisms that are not in a state of torpor is higher, and in very hot conditions it is lower. The reason for the excess of body temperature above the environment is that even at a low level of metabolism, endogenous heat is produced - it causes an increase in body temperature. This is manifested, in particular, in a significant increase in temperature in actively moving animals. For example, in insects at rest, the excess of body temperature above the environment is expressed in tenths of a degree, while in actively flying butterflies, bumblebees and other species, the temperature is maintained at 36–40 ° C even at air temperatures below 10 ° C.

A temperature lower than the environment during heat is characteristic of terrestrial organisms and is primarily explained by heat loss with evaporation, which increases significantly at high temperature and low humidity.

The rate of change in body temperature of poikilotherms is inversely related to their size. This is primarily determined by the ratio of mass and surface: for more large forms the relative surface of the body decreases, which leads to a decrease in the rate of heat loss. This is of great ecological importance, determining for different species the possibility of settling geographic regions or biotopes with certain temperature regimes. It has been shown, for example, that in large leatherback turtles caught in cold waters, the temperature in the depths of the body was -18 ° C higher than the water temperature; it is their large size that allows these turtles to penetrate into colder regions of the ocean, which is not characteristic of smaller species.
2.1 Passive stability
The regularities considered cover the range of temperature changes within which active vital activity is preserved. Beyond this range, which vary widely in different species and even geographical populations of the same species, active forms of activity of poikilothermic organisms cease, and they pass into a state of stupor, characterized by a sharp decrease in the level of metabolic processes, up to a complete loss of visible manifestations of life. In such a passive state, poikilothermic organisms can tolerate a fairly strong increase and an even more pronounced decrease in temperature without pathological consequences. The basis of this temperature tolerance lies in the high degree of tissue resistance inherent in all poikilothermic species and often maintained by severe dehydration (seeds, spores, some small animals).

The transition to a state of stupor should be considered as an adaptive reaction: an almost non-functioning organism is not exposed to many damaging effects, and also does not consume energy, which allows it to survive under adverse temperature conditions for a long time. Moreover, the very process of transition to a state of stupor can be a form of active restructuring of the type of reaction to temperature. "Hardening" of frost-resistant plants is an active seasonal process, proceeding in stages and associated with rather complex physiological and biochemical changes in the body. In animals, falling into a stupor under natural conditions is also often expressed seasonally and is preceded by a complex of physiological changes in the body. There is evidence that the process of transition to torpor may be regulated by some hormonal factors; objective material on this subject is not yet sufficient for broad conclusions.

When the temperature of the environment goes beyond the limits of tolerance, the death of the organism occurs from the causes considered at the beginning of this chapter.
2.2 Metabolic rate
Temperature variability entails corresponding changes in the rate of exchange reactions. Since the dynamics of the body temperature of poikilothermic organisms is determined by changes in the temperature of the environment, the intensity of metabolism also turns out to be directly dependent on the external temperature. The rate of oxygen consumption, in particular, with rapid changes in temperature follows these changes, increasing when it rises and decreasing when it decreases. The same applies to other physiological functions: heart rate, digestion intensity, etc. In plants, depending on temperature, the rate of water intake and nutrients through the roots: raising the temperature to a certain limit increases the permeability of the protoplasm for water. It has been shown that when the temperature drops from 20 to 0 "C, the absorption of water by the roots decreases by 60 - 70%. Like in animals, an increase in temperature causes an increase in respiration in plants.

The last example shows that the effect of temperature is not linear: upon reaching a certain threshold, the stimulation of the process is replaced by its suppression. This is a general rule, due to the approach to the zone of the threshold of normal life.

In animals, the dependence on temperature is very markedly expressed in changes in activity, which reflects the total reaction of the organism, and in poikilothermic forms it depends most significantly on temperature conditions. It is well known that insects, lizards and many other animals are most mobile during the warm time of the day and on warm days, while in cool weather they become lethargic and inactive. The beginning of their vigorous activity is determined by the rate of warming up of the body, which depends on the temperature of the environment and on direct solar irradiation. The level of mobility of active animals, in principle, is also related to the ambient temperature, although in the most active forms this relationship can be “masked” by endogenous heat production associated with the work of the muscles.

2.3 Temperature adaptations

Poikilothermic living organisms are common in all environments, occupying habitats of various temperature conditions, up to the most extreme ones: they practically live in the entire temperature range recorded in the biosphere. Keeping in all cases the general principles of temperature reactions (discussed above), different species and even populations of the same species exhibit these reactions in accordance with the characteristics of the climate, adapt the body's responses to a certain range of temperature effects. This manifests itself, in particular, in the forms of resistance to heat and cold: species that live in colder climates are more resistant to low temperatures and less to high; inhabitants of hot regions exhibit reverse reactions.

It is known that tropical forest plants are damaged and die at temperatures of + 5 ... + 8 0С, while the inhabitants of the Siberian taiga withstand complete freezing in a state of stupor.

Various species of carp-toothed fish showed a clear correlation of the upper lethal threshold with the water temperature in the reservoirs characteristic of the species.

Arctic and Antarctic fish, on the contrary, show high resistance to low temperatures and are very sensitive to its increase. Thus, Antarctic fish die when the temperature rises to 6 "C. Similar data were obtained for many species of poikilothermic animals. For example, observations on the island of Hokkaido (Japan) showed a clear connection between the cold resistance of several species of beetles and their larvae with their winter ecology: the most stable were found to be species wintering in the litter, forms wintering in the depths of the soil were characterized by low resistance to freezing and a relatively high temperature of hypothermia.In experiments with amoebas, it was found that their heat resistance directly depends on the temperature of cultivation.
3. HOMOYOTHERM ORGANISMS
This group does not include two classes of higher vertebrates - birds and mammals. The fundamental difference between heat exchange in homoiothermic animals and poikilothermic animals is that their adaptations to changing temperature conditions of the environment are based on the functioning of a complex of active regulatory mechanisms for maintaining thermal homeostasis of the internal environment of the body. Due to this, biochemical and physiological processes always proceed in optimal temperatures conditions.

The homeothermal type of heat exchange is based on the high metabolic rate characteristic of birds and mammals. The intensity of metabolism in these animals is one or two orders of magnitude higher than in all other living organisms at the optimum environmental temperature. So, in small mammals, oxygen consumption at an ambient temperature of 15 - 0 "C is approximately 4 - thousand cm 3 kg -1 h -1, and in invertebrates at the same temperature - 10 - 0 cm 3 kg -1 h -1 With the same body weight (2.5 kg), the daily metabolism of a rattlesnake is 32.3 J / kg (382 J / m 2), for a marmot - 120.5 J / kg (1755 J / m 2), for a rabbit - 188.2 J / kg (2600 J / m 2).

A high level of metabolism leads to the fact that in homoiothermic animals the heat balance is based on the use of their own heat production, the value of external heating is relatively small. Therefore, birds and mammals are classified as endothermic "organisms. Endothermy is an important property, due to which the dependence of the organism's vital activity on the ambient temperature is significantly reduced.
3.1 Body temperature
Homeothermic animals are not only provided with heat due to their own heat production, but are also able to actively regulate its production and consumption. Due to this, they are characterized by a high and fairly stable body temperature. In birds, the normal deep body temperature is about 41 "C, with fluctuations in different species from 38 to 43.5" C (data for 400 species). Under conditions of complete rest (basal metabolism), these differences are somewhat smoothed out, ranging from 39.5 to 43.0 "C. At the level of an individual organism, body temperature shows a high degree of stability: the range of its daily changes usually does not exceed 2 - ~ 4" C, moreover, these fluctuations are not related to air temperature, but reflect the rhythm of metabolism. Even in arctic and antarctic species, at ambient temperatures up to 20 - 50 "C frost, body temperature fluctuates within the same 2 - 4" C.

An increase in environmental temperature is sometimes accompanied by some increase in body temperature. If we exclude pathological conditions, it turns out that in living conditions in a hot climate, a certain degree of hyperthermia can be adaptive: this reduces the difference in body temperature and the environment and reduces the cost of water for evaporative thermoregulation. A similar phenomenon was noted in some mammals: in a camel, for example, with a lack of water, the body temperature can rise from 34 to 40 ° C. In all such cases, an increased tissue resistance to hyperthermia was noted.

In mammals, the body temperature is somewhat lower than in birds, and in many species it is subject to greater fluctuations. Different taxa also differ in this indicator. In monotremes, the rectal temperature is 30 - 3 "C (at an ambient temperature of 20" C), in marsupials it is slightly higher - about 34 "C at the same external temperature. In representatives of both these groups, as well as in edentulous, fluctuations in body temperature are quite noticeable in connection with the external temperature: when the air temperature dropped from 20 - 5 to 14 -15 "C, a drop in body temperature was recorded by more than two degrees, and in some cases even by 5" C. In rodents, the average body temperature in the active state fluctuates within 35 - 9.5 "C, in most cases amounting to 36 - 37" C. The degree of stability of their rectal temperature is normally higher than that of the previously considered groups, but they also have fluctuations within 3 - "C when changing external temperature from 0 to 35 "C.

In ungulates and carnivores, the body temperature is maintained very steadily at the level characteristic of the species; interspecific differences usually fit in the range from 35.2 to 39 "C. For many mammals, a decrease in temperature during sleep is characteristic; the magnitude of this decrease varies in different species from tenths of a degree to 4 - "C.

All of the above refers to the so-called deep body temperature, which characterizes the thermal state of the thermostatically controlled "core" of the body. In all homoiothermic animals, the outer layers of the body (integuments, part of the muscles, etc.) form a more or less pronounced "shell", the temperature of which varies over a wide range. Thus, a stable temperature characterizes only the area of localization of important internal organs and processes. Surface fabrics withstand more pronounced temperature fluctuations. This can be beneficial for the body, since in such a situation the temperature gradient at the boundary of the body and the environment decreases, which makes it possible to maintain thermal homeostasis of the “core” of the body with less energy consumption.
3.2 Mechanisms of thermoregulation
Physiological mechanisms that provide thermal homeostasis of the body (its "core") are divided into two functional groups: the mechanisms of chemical and physical thermoregulation. Chemical thermoregulation is the regulation of body heat production. Heat is constantly produced in the body in the process of redox reactions of metabolism. At the same time, part of it is given to the external environment the more, the greater the difference between the temperature of the body and the environment. Therefore, maintaining a stable body temperature with a decrease in environmental temperature requires a corresponding increase in metabolic processes and the accompanying heat generation, which compensates for heat loss and leads to the preservation of the overall heat balance of the body and maintaining a constant internal temperature. The process of reflex enhancement of heat production in response to a decrease in ambient temperature is called chemical thermoregulation. The release of energy in the form of heat accompanies the functional load of all organs and tissues and is characteristic of all living organisms. The specificity of homoiothermic animals is that the change in heat production as a reaction to changing temperature is a special reaction of the organism in them, which does not affect the level of functioning of the main physiological systems.

Specific thermoregulatory heat generation is concentrated mainly in the skeletal muscles and is associated with special forms functioning of muscles that do not affect their direct motor activity. An increase in heat generation during cooling can also occur in a resting muscle, as well as when the contractile function is artificially turned off by the action of specific poisons.

One of the most common mechanisms of specific thermoregulatory heat generation in muscles is the so-called thermoregulatory tone. It is expressed by microcontractions of fibrils, recorded as an increase in the electrical activity of an externally immobile muscle during its cooling. Thermoregulatory tone increases oxygen consumption by the muscle, sometimes by more than 150%. With stronger cooling, along with a sharp increase in thermoregulatory tone, visible muscle contractions in the form of cold shivering are included. At the same time, gas exchange increases to 300 - 400%. Characteristically, in terms of the share of participation in thermoregulatory heat generation, the muscles are unequal. In mammals, the role of the masticatory muscles and the muscles that support the posture of the animal, i.e., functioning mainly as tonic, is the greatest. In birds, a similar phenomenon is observed.

With prolonged exposure to cold, the contractile type of thermogenesis can be replaced (or supplemented) to one degree or another by switching tissue respiration in the muscle to the so-called free (non-phosphorylating) pathway, in which the phase of formation and subsequent breakdown of ATP falls out. This mechanism is not associated with the contractile activity of the muscles. The total mass of heat released during free respiration is practically the same as during yeast thermogenesis, but most of the heat energy is consumed immediately, and oxidative processes cannot be inhibited by a lack of ADP or inorganic phosphate.

The latter circumstance makes it possible to freely maintain a high level of heat generation for a long time.

In mammals, there is another form of non-yeast thermogenesis associated with the oxidation of a special brown adipose tissue deposited under the skin in the interscapular space, neck and thoracic spine. Brown fat contains a large number of mitochondria and is riddled with numerous blood vessels. Under the influence of cold, the blood supply to brown fat increases, its respiration intensifies, and the release of heat increases. It is important that in this case, nearby organs are directly heated: heart, large vessels, lymph nodes, as well as the central nervous system. Brown fat is used mainly as a source of emergency heat generation, in particular, when warming up the body of animals emerging from hibernation. The role of brown fat in birds is not clear. For a long time it was believed that they did not have it at all; Recently there have been reports of the discovery of this type of adipose tissue in birds, but neither accurate identification nor functional evaluation of it has been carried out.

Changes in the intensity of metabolism caused by the influence of environmental temperature on the body of homoiothermic animals are natural. In a certain range of external temperatures, heat production, corresponding to the exchange of a resting organism, is completely compensated by its “normal” (without active intensification) heat transfer. The heat exchange of the body with the environment is balanced. This temperature range is called the thermoneutral zone. The level of exchange in this zone is minimal. Often they speak of a critical point, implying a specific temperature value at which a thermal balance with the environment is achieved. Theoretically, this is true, but it is practically impossible to establish such a point experimentally due to constant irregular fluctuations in metabolism and the instability of the heat-insulating properties of the covers.

A decrease in the temperature of the environment outside the thermoneutral zone causes a reflex increase in the level of metabolism and heat production until the body's heat balance is balanced under new conditions. Because of this, the body temperature remains unchanged.

An increase in the temperature of the environment outside the thermoneutral zone also causes an increase in the level of metabolism, which is caused by the activation of mechanisms for activating heat transfer, requiring additional energy costs for their work. Thus, a zone of physical thermoregulation is formed, during which the temperature of the takyr remains stable. Upon reaching a certain threshold, the mechanisms for enhancing heat transfer turn out to be ineffective, overheating begins and, finally, the death of the organism.

Specific differences in chemical thermoregulation are expressed in the difference in the level of the main (in the zone of thermoneutrality) metabolism, the position and width of the thermoneutral zone, the intensity of chemical thermoregulation (an increase in metabolism with a decrease in ambient temperature by 1 "C), as well as in the range of effective thermoregulation. All these parameters reflect ecological specificity of individual species and adaptively change depending on geographical location region, season of the year, altitude and a number of other environmental factors.

Physical thermoregulation combines a complex of morphophysiological mechanisms associated with the regulation of body heat transfer as one of the components of its overall heat balance. The main device that determines the overall level of heat transfer from the body of a homoiothermic animal is the structure of heat-insulating covers. Heat-insulating structures (feathers, hair) do not cause homoiothermia, as is sometimes thought. It is based on high and that, by reducing heat loss, it contributes to maintaining homoiothermy with less energy costs. This is especially important when living in conditions of consistently low temperatures; therefore, heat-insulating integumentary structures and layers of subcutaneous fat are most pronounced in animals from cold climate regions.

The mechanism of the heat-insulating action of feather and hair covers is that groups of hair or feathers, arranged in a certain way, different in structure, hold a layer of air around the body, which acts as a heat insulator. Adaptive changes in the heat-insulating function of the integuments are reduced to a restructuring of their structure, including the ratio of different types of hair or feathers, their length and density. It is in these parameters that the inhabitants of various climatic zones differ, they also determine seasonal changes in thermal insulation. It has been shown, for example, that in tropical mammals the thermal insulation properties of the coat are almost an order of magnitude lower than in the inhabitants of the Arctic. The same adaptive direction is followed by seasonal changes in the heat-insulating properties of the covers during the molting process.

The considered features characterize the stable properties of heat-insulating covers, which determine the overall level of heat losses, and, in essence, do not represent active thermoregulatory reactions. The possibility of labile regulation of heat transfer is determined by the mobility of feathers and hair, due to which, against the background of an unchanged cover structure, rapid changes in the thickness of the heat-insulating air layer, and, accordingly, the intensity of heat transfer, are possible. The degree of looseness of hair or feathers can change rapidly depending on the air temperature and on the activity of the animal itself. This form of physical thermoregulation is referred to as the pilomotor reaction. This form of heat transfer regulation operates mainly at low ambient temperatures and provides no less rapid and effective response to heat balance disturbances than chemical thermoregulation, while requiring less energy.

Regulatory responses aimed at maintaining a constant body temperature during overheating are represented by various mechanisms for enhancing heat transfer to the external environment. Among them, heat transfer is widespread and has a high efficiency by intensifying the evaporation of moisture from the surface of the body and (and) the upper respiratory tract. When moisture evaporates, heat is consumed, which can contribute to maintaining the heat balance. The reaction is turned on when there are signs of an incipient overheating of the body. Thus, adaptive changes in heat transfer in homoiothermic animals can be aimed not only at maintaining high level metabolism, as in most birds and mammals, but also to a low level setting in conditions that threaten to deplete energy reserves.
Bibliography
1. Fundamentals of ecology: Textbook VV Mavrishchev. Mn.: Vysh. Shk., 2003. - 416 p.

2. http :\\Abiotic environmental factors.htm

3. http :\\Abiotic environmental factors and organisms.htm

I found an article here on the Internet. Passion, as interested, but I don’t risk trying it on myself yet. Spread for review, and there is someone bolder - I will be glad to feedback.

I will tell you about one of the most incredible, from the point of view of everyday ideas, practices - the practice of free adaptation to the cold.

According to generally accepted ideas, a person cannot be in the cold without warm clothes. The cold is absolutely fatal, and it is worth going out without a jacket by the will of fate, as the unfortunate person is in for a painful freezing, and an inevitable bouquet of diseases upon return.

In other words, generally accepted ideas completely deny a person the ability to adapt to the cold. The comfort range is considered to be exclusively above room temperature.

Like you can't argue. You can’t spend the whole winter in Russia in shorts and a T-shirt ...

That's just the point, it's possible!!

No, not gritting your teeth, acquiring icicles to set a ridiculous record. And freely. Feeling, on average, even more comfortable than those around you. It's real practical experience, crushingly breaking the generally accepted patterns.

It would seem, why own such practices? Yes, everything is very simple. New horizons always make life more interesting. Removing inspired fears, you become freer.
The range of comfort is vastly expanded. When the rest is either hot or cold, you feel good everywhere. Phobias disappear completely. Instead of the fear of getting sick, if you don’t dress warmly enough, you get complete freedom and self-confidence. It's really nice to run in the cold. If you go beyond your limits, then this does not entail any consequences.

How is this even possible? Everything is very simple. We are much better off than we think. And we have mechanisms that allow us to be free in the cold.

Firstly, with temperature fluctuations within certain limits, the metabolic rate, the properties of the skin, etc. change. In order not to dissipate heat, the outer contour of the body greatly reduces the temperature, while the core temperature remains very stable. (Yes, cold paws are normal!! No matter how we were convinced in childhood, this is not a sign of freezing!)

With an even greater cold load, specific mechanisms of thermogenesis are activated. We know about contractile thermogenesis, in other words, shivering. The mechanism is, in fact, an emergency. Trembling warms, but it turns on not from a good life, but when you really get cold.

But there is also non-shivering thermogenesis, which produces heat through the direct oxidation of nutrients in the mitochondria directly into heat. In the circle of people practicing cold practices, this mechanism was simply called the "stove". When the "stove" is switched on, heat is produced in the background in an amount sufficient for a long stay in the cold without clothes.

Subjectively, it feels rather unusual. In Russian, the word "cold" refers to two fundamentally different sensations: "it's cold outside" and "it's cold for you." They may be present independently. You can freeze in a fairly warm room. And you can feel the skin burning cold outside, but not freeze at all and not experience discomfort. Moreover, it's nice.

How can one learn to use these mechanisms? I will say emphatically that I consider “learning by article” risky. Technology must be handed over personally.

Non-shivering thermogenesis starts in a fairly severe frost. And turning it on is quite inertial. The "stove" starts to work not earlier than in a few minutes. Therefore, paradoxically, learning to walk freely in the cold is much easier in severe frost than on a cool autumn day.

It is worth going out into the cold, as you begin to feel the cold. An inexperienced person is seized with panic horror. It seems to him that if it is already cold now, then in ten minutes there will be a full paragraph. Many simply do not wait for the "reactor" to enter the operating mode.

When the “stove” nevertheless starts up, it becomes clear that, contrary to expectations, it is quite comfortable to be in the cold. This experience is useful in that it immediately breaks the patterns instilled in childhood about the impossibility of this, and helps to look at reality in a different way as a whole.

For the first time, you need to go out into the cold under the guidance of a person who already knows how to do it, or where you can return to warmth at any time!

And you have to go out naked. Shorts, better even without a T-shirt and nothing else. The body needs to be properly frightened so that it turns on the forgotten adaptation systems. If you get scared and put on a sweater, trowel, or something similar, then the heat loss will be enough to freeze very hard, but the "reactor" will not start!

For the same reason, gradual "hardening" is dangerous. Dropping the temperature of the air or bath "by one degree in ten days" leads to the fact that sooner or later there comes a moment when it is already cold enough to get sick, but not enough to trigger thermogenesis. Truly, only iron people. But almost everyone can immediately go out into the cold or dive into the hole.

After what has been said, one can already guess that adaptation not to frost, but to low positive temperatures is a more difficult task than jogging in frost, and it requires higher preparation. The "stove" at +10 does not turn on at all, and only non-specific mechanisms work.

It should be remembered that severe discomfort cannot be tolerated. When everything goes right, no hypothermia develops. If you start to feel very cold, then you need to stop the practice. Periodic exits beyond the limits of comfort are inevitable (otherwise, these limits cannot be pushed), but extreme should not be allowed to grow into pipets.

The heating system eventually gets tired of working under load. Endurance limits are very far. But they are. You can freely walk at -10 all day, and at -20 for a couple of hours. But it will not work to go skiing in one T-shirt. (Field conditions are generally a separate issue. In winter, you can’t save on clothes taken with you on a hike! You can put them in a backpack, but you can’t forget them at home. In snowless times, you can risk leaving extra things at home that are taken only because of fear of weather, but if you have experience)

For greater comfort, it is better to walk like this for more or less clean air, away from sources of smoke and from smog - sensitivity to what we breathe in this state increases significantly. It is clear that practice is generally incompatible with smoking and booze.

Being in the cold can cause cold euphoria. The feeling is pleasant, but requires the utmost self-control, in order to avoid the loss of adequacy. This is one of the reasons why it is highly undesirable to start a practice without a teacher.

Another important nuance is a long reboot of the heating system after significant loads. Having caught the cold properly, you can feel pretty good, but when you enter a warm room, the “stove” turns off, and the body begins to warm up with a shiver. If at the same time you go out into the cold again, the “stove” will not turn on, and you can freeze very much.

Finally, you need to understand that the possession of practice does not guarantee not to freeze anywhere and never. The state changes, and many factors influence. But, the probability of getting into trouble from the weather is still reduced. Just as the probability of being physically blown away by an athlete is in any way lower than that of a squishy one.

Alas, it was not possible to create a complete article. I'm only in in general terms outlined this practice (more precisely, a set of practices, because diving into an ice hole, jogging in a T-shirt in the cold and wandering through the forest in the style of Mowgli are different). Let me summarize what I started with. Owning your own resources allows you to get rid of fears, and feel much more comfortable. And it's interesting.

I'll tell you about one of the most incredible, from the point of view of ordinary ideas, practices - the practice of free adaptation to the cold.

According to generally accepted ideas, a person cannot be in the cold without warm clothes. The cold is absolutely fatal, and it is worth going out into the street without a jacket by the will of fate, as the unfortunate person is in for a painful freezing, and an inevitable bunch of diseases upon his return.

In other words, generally accepted ideas completely deny a person the ability to adapt to the cold. The comfort range is considered to be exclusively above room temperature.

Like you can't argue. You can’t spend the whole winter in Russia in shorts and a T-shirt ...

That's just the point, it's possible!!

No, not gritting your teeth, acquiring icicles to set a ridiculous record. And freely. Feeling, on average, even more comfortable than those around you. This is a real practical experience, crushingly breaking the generally accepted patterns.

How is this even possible? Everything is very simple. We are much better off than we think. And we have mechanisms that allow us to be free in the cold.

How can one learn to use these mechanisms? I will say emphatically that I consider “learning by article” risky. Technology must be handed over personally.

For the first time, you need to go out into the cold under the guidance of a person who already knows how to do it, or where you can return to warmth at any time!

For the same reason, gradual "hardening" is dangerous. Dropping the temperature of the air or bath "by one degree in ten days" leads to the fact that sooner or later there comes a moment when it is already cold enough to get sick, but not enough to trigger thermogenesis. Truly, only iron people can withstand such hardening. But almost everyone can immediately go out into the cold or dive into the hole.

For greater comfort, it is better to walk like this in more or less clean air, away from sources of smoke and from smog - sensitivity to what we breathe in this state increases significantly. It is clear that practice is generally incompatible with smoking and booze.

Alas, it was not possible to create a complete article. I only outlined this practice in general terms (more precisely, a set of practices, because diving into an ice hole, jogging in a T-shirt in the cold and wandering through the forest in the style of Mowgli are different). Let me summarize what I started with. Owning your own resources allows you to get rid of fears, and feel much more comfortable. And it's interesting.

Belgorod regional public organization

MBOUDOD "Center for Children's and Youth Tourism and Excursions"

G. Belgorod

Methodical development

Subject:"Physiological basis of adaptation of the athlete's body to new climatic conditions"

trainer-teacher TsDYUTE

Belgorod, 2014

1. Concept of adaptation

2. Adaptation and homeostasis

3. Cold adaptation

4. Acclimatization. mountain sickness

5. The development of specific endurance as a factor contributing to high-altitude acclimatization

1. Concept of adaptation

Adaptationis a process of adaptation that is formed during a person's life. Thanks to adaptive processes, a person adapts to unusual conditions or a new level of activity, i.e., increases the resistance of his body against the action of various factors. The human body can adapt to high and low temperatures, emotional stimuli (fear, pain, etc.), low atmospheric pressure, or even some pathogenic factors.

For example, a climber adapted to a lack of oxygen can climb a mountain peak with a height of 8000 m or more, where the partial pressure of oxygen approaches 50 mm Hg. Art. (6.7 kPa). The atmosphere at such an altitude is so rarefied that an untrained person dies in a few minutes (due to lack of oxygen) even at rest.

People living in the northern or southern latitudes, in the mountains or on the plains, in the humid tropics or in the desert, differ from each other in many indicators of homeostasis. Therefore, a number of normal indicators for individual regions of the globe may differ.

We can say that human life in real conditions is a constant adaptation process. Its body adapts to the effects of various climatic and geographical, natural (atmospheric pressure and gas composition of air, duration and intensity of insolation, temperature and humidity, seasonal and daily rhythms, geographical longitude and latitude, mountains and plains, etc.) and social factors, conditions of civilization . As a rule, the body adapts to the action of a complex of various factors.The need to stimulate the mechanisms that drive the process of adaptation arises as the strength or duration of the impact of a number of external factors increases. For example, in the natural conditions of life, such processes develop in autumn and spring, when the body is gradually rebuilt, adapting to cold weather or warming.

Adaptation also develops when a person changes the level of activity and begins to engage in physical education or some uncharacteristic type. labor activity, i.e., the activity of the motor apparatus increases. In modern conditions, in connection with the development rapid transit a person often changes not only climatic and geographical conditions, but also time zones. This leaves its mark on biorhythms, which is also accompanied by the development of adaptive processes.

2. Adaptation and homeostasis

A person is forced to constantly adapt to changing environmental conditions, preserving his body from destruction under the influence of external factors. The preservation of the body is possible due to homeostasis - a universal property to preserve and maintain the stability of the work of various body systems in response to influences that violate this stability.

homeostasis- relative dynamic constancy of the composition and properties of the internal environment and the stability of the basic physiological functions of the body. Any physiological, physical, chemical or emotional impact, whether it be air temperature, changes in atmospheric pressure or excitement, joy, sadness, may be the reason for the body to exit the state of dynamic equilibrium. Automatically, with the help of humoral and nervous mechanisms of regulation, self-regulation of physiological functions is carried out, which ensures the maintenance of the vital activity of the organism at a constant level. Humoral regulation is carried out through the liquid internal environment of the body with the help of chemical molecules released by cells or certain tissues and organs (hormones, enzymes, etc.). Nervous regulation provides fast and directed transmission of signals in the form of nerve impulses arriving at the object of regulation.

Reactivity is an important property of a living organism that affects the efficiency of regulatory mechanisms. Reactivity is the ability of an organism to respond (react) with changes in metabolism and function to stimuli of the external and internal environment. Compensation for changes in environmental factors is possible due to the activation of systems responsible for adaptation(adaptation) of the organism to external conditions.

Homeostasis and adaptation are the two end results that organize functional systems. The intervention of external factors in the state of homeostasis leads to an adaptive restructuring of the body, as a result of which one or more functional systems compensate for possible disturbances and restore balance.

3. Cold adaptation

In the high mountains, under conditions of increased physical exertion, the most significant processes are acclimatization - adaptation to cold.

The optimal microclimatic zone corresponds to the temperature range of 15...21 °С; it ensures a person's well-being and does not cause shifts in thermoregulation systems;

The permissible microclimatic zone corresponds to the temperature range from minus 5.0 to plus 14.9°C and 21.7...27.0°C; ensures the preservation of human health for a long time of exposure, but causes discomfort, as well as functional shifts that do not go beyond the limits of its physiological adaptive capabilities. When in this zone, the human body is able to maintain a temperature balance due to changes in skin blood flow and sweating for a long time without deteriorating health;

Maximum permissible microclimatic zone, effective temperatures from 4.0 to minus 4.9°С and from 27.1 to 32.0°С. Maintaining a relatively normal functional state for 1-2 hours is achieved due to the tension of the cardiovascular system and the thermoregulation system. Normalization of the functional state occurs after 1.0-1.5 hours of stay in an optimal environment. Frequent repeated exposures lead to disruption of volumetric processes, depletion defensive forces organism, reducing its nonspecific resistance;

Extremely tolerable microclimatic zone, effective temperatures from minus 4.9 to minus 15.0 ºС and from 32.1 to 38.0 °С.

Performance of loading at temperatures in the specified ranges results in 30-60 min. to a pronounced change in the functional state: at low temperatures it is cool in fur clothes, hands in fur gloves freeze: at high temperatures heat sensation "hot", "very hot", lethargy, unwillingness to work, headache, nausea, irritability appear; sweat, abundantly flowing from the forehead, gets into the eyes, interferes; with an increase in symptoms of overheating, vision is impaired.

The dangerous microclimatic zone below minus 15 and above 38 ° C is characterized by such conditions that after 10-30 minutes. May lead to poor health.

Uptime

when performing a load in adverse microclimatic conditions

Microclimate zone	Below optimal temperatures	Above optimal temperatures
Effective temperature, С	Time, min.	Effective temperature, С	Time, min.
Permissible	5,0…14,9	60 – 120	21,7…27,0	30 – 60
Maximum allowable	From 4.9 to minus 4.9	30 – 60	27,1…32,0	20 – 30
Extremely portable	Minus 4.9…15.0	10 – 30	32,1…38,0	10 – 20
dangerous	Below minus 15.1	5 – 10	Above 38.1	5 – 10

4 . Acclimatization. mountain sickness

As you go up in altitude, air pressure drops. Accordingly, the pressure of all components of air, including oxygen, drops. This means that the amount of oxygen entering the lungs during inhalation is less. And oxygen molecules are less intensively attached to blood erythrocytes. The concentration of oxygen in the blood decreases. The lack of oxygen in the blood is called hypoxia. Hypoxia leads to the development mountain sickness.

Typical manifestations of altitude sickness:

· increased heart rate;

· shortness of breath on exertion;

· headache, insomnia;

· weakness, nausea and vomiting;

· inappropriate behaviour.

In advanced cases, mountain sickness can lead to serious consequences.

To be safe at high altitudes, you need acclimatization- adaptation of the body to high altitude conditions.

Acclimatization is impossible without altitude sickness. Mild forms of mountain sickness trigger the body's restructuring mechanisms.

There are two phases of acclimatization:

· Short term acclimatization is a rapid response to hypoxia. The changes mainly concern oxygen transport systems. The frequency of respiration and heartbeat increases. Additional erythrocytes are ejected from the blood depot. There is a redistribution of blood in the body. Increases cerebral blood flow, because the brain requires oxygen. This is what leads to headaches. But such adaptation mechanisms can only be effective for a short time. At the same time, the body experiences stress and wears out.

· Long-term acclimatization - a complex of profound changes in the body. It is she who is the purpose of acclimatization. In this phase, the focus shifts from transport mechanisms to mechanisms economical use oxygen. The capillary network grows, the area of the lungs increases. The composition of the blood changes - embryonic hemoglobin appears, which more easily attaches oxygen at its low partial pressure. The activity of enzymes that break down glucose and glycogen increases. The biochemistry of myocardial cells changes, which allows more efficient use of oxygen.

Step acclimatization

When climbing to a height, the body experiences a lack of oxygen. Mild mountain sickness sets in. Mechanisms of short-term acclimatization are included. For effective acclimatization after the ascent, it is better to go down, so that changes in the body occur in more favorable conditions and there is no exhaustion of the body. This is the principle of stepwise acclimatization - a sequence of ascents and descents, in which each subsequent ascent is higher than the previous one.

Rice. 1. Sawtooth graph of stepwise acclimatization

Sometimes the features of the relief do not provide an opportunity for a full-fledged stepwise acclimatization. For example, on many tracks in the Himalayas, where climbing takes place daily. Then daytime transitions are made small so that the height increase does not occur too quickly. It is very useful in this case to look for an opportunity to make even a small exit up from the place of spending the night. Often you can take a walk in the evening on a nearby hill or a spur of a mountain, and gain at least a couple of hundred meters.

What should be done to ensure successful acclimatization before the trip?

General physical training . It is easier for a trained athlete to endure the loads associated with height. First of all, you should develop endurance. This is achieved by sustained low-intensity exercise. Most accessible means endurance development is run.

It is practically useless to run often, but little by little. It is better to run once a week for 1 hour than every day for 10 minutes. For the development of endurance, the length of the runs should be more than 40 minutes, the frequency - according to the sensations. It is important to monitor the pulse rate and not overload the heart. In general, training should be enjoyable, fanaticism is not needed.

Health.It is very important to come to the mountains healthy and rested. If you have been training, then three weeks before the trip, reduce the load and give the body a rest. Mandatory good sleep and food. Nutrition can be supplemented with vitamins and minerals. Minimize or better avoid alcohol. Avoid stress and overwork at work. You need to fix your teeth.

In the early days, the body is subject to heavy loads. The immune system weakens and it is easy to get sick. Avoid hypothermia or overheating. In the mountains, there are sharp temperature changes and therefore you need to follow the rule - undress before you sweat, dress before you get cold.

Appetite at altitude can be reduced, especially if you immediately go to high altitudes. There is no need to force. Give preference to easily digestible foods. In the mountains, due to the dryness of the air and heavy physical exertion, a person needs a large amount of water - drink a lot.

Continue taking vitamins and minerals. You can start taking amino acids that have adaptogenic properties.

Movement mode.It happens that only after arriving in the mountains, tourists, experiencing an emotional upsurge and feeling overwhelmed by their strength, go too fast along the path. You need to restrain yourself, the pace of movement should be calm and uniform. In the early days in the highlands, the pulse at rest is 1.5 times higher than in the plains. It’s already hard for the body, so you don’t need to drive, especially on the climbs. Small tears may not be noticeable, but tend to accumulate, and can lead to a breakdown in acclimatization.

If you come to the place of spending the night, and you do not feel well, you do not need to go to bed. It is better to walk at a calm pace around the neighborhood, take part in the arrangement of the bivouac, in general, do something.

Movement and work - an excellent cure for mild forms of mountain sickness. Night is a very important time for acclimatization. Sleep must be sound. If you have a headache in the evening, take a painkiller. Headache destabilizes the body and cannot be tolerated. If you can't sleep, take sleeping pills. You can't stand insomnia either.

Check your heart rate before bed and in the morning immediately after waking up. The morning pulse should be lower - this is an indicator that the body has rested.

With well-planned preparation and the right climb schedule, you can avoid serious manifestations of altitude sickness and enjoy the conquest of great heights.

5. Development of specific endurance as a factor contributing to high-altitude acclimatization

"If a climber (mountain tourist) in the off-season and pre-season increases his "oxygen ceiling" by swimming, running, cycling, skiing, rowing, he will ensure the improvement of his body, he will then be more successful in coping with great, but exciting difficulties when storming mountain peaks ".

This recommendation is both true and false. In the sense that it is, of course, necessary to prepare for the mountains. But cycling, rowing, swimming and other types of training give different “improvement of your body” and, accordingly, a different “oxygen ceiling”. When we are talking about the motor acts of the body, one should clearly understand that there is no "movement in general" and any motor act is extremely specific. And from a certain level, the development of one physical quality always occurs at the expense of another: strength due to endurance and speed, endurance due to strength and speed.

When training for intensive work the consumption of oxygen and oxidation substrates in the muscles per unit time is so high that it is unrealistic to quickly replenish their reserves by increasing the work of transport systems. The sensitivity of the respiratory center to carbon dioxide is reduced, which protects the respiratory system from unnecessary overstrain.

Muscles capable of performing such a load actually work in autonomous mode, relying on their own resources. This does not eliminate the development of tissue hypoxia and leads to the accumulation of large amounts of underoxidized products. An important aspect adaptive reactions in this case is the formation of tolerance, that is, resistance to pH shift. This is ensured by an increase in the capacity of the buffer systems of blood and tissues, an increase in the so-called. alkaline reserve of the blood. The power of the antioxidant system in the muscles also increases, which weakens or prevents lipid peroxidation of cell membranes - one of the main damaging effects of the stress response. The power of the anaerobic glycolysis system increases due to the increased synthesis of glycolytic enzymes, the reserves of glycogen and creatine phosphate, energy sources for ATP synthesis, increase.

When training for moderate work the growth of the vascular network in the muscles, heart, lungs, an increase in the number of mitochondria and a change in their characteristics, an increase in the synthesis of oxidative enzymes, an increase in erythropoiesis, leading to an increase in the oxygen capacity of the blood, can reduce the level of hypoxia or prevent it. With the systematic performance of moderate physical activity, accompanied by an increase in pulmonary ventilation, the respiratory center, on the contrary, increases sensitivity to CO 2 , which is due to a decrease in its content due to leaching from the blood during increased breathing.

Therefore, in the process of adaptation to intensive (as a rule, short-term) work, a different spectrum of adaptive adaptations develops in the muscles than to long-term moderate work. Therefore, for example, during hypoxia during diving, it becomes impossible to activate external respiration, which is typical for adaptation to high-altitude hypoxia or hypoxia during muscular work. And the struggle to maintain oxygen homeostasis is manifested in an increase in oxygen reserves carried under water. Consequently, the range of adaptive devices at different types hypoxia - varies, therefore - not always useful for high mountains.

Table. The volume of circulating blood (BCC) and its components in athletes training endurance and untrained (L. Röcker, 1977).
Indicators	Athletes	Not athletes
BCC [l]	6,4	5,5
BCC [ml/kg body weight]	95,4	76,3
Volume of circulating plasma (CVV) [l]	3,6	3,1
VCP [ml/kg body weight]	55,2	43
Volume of circulating erythrocytes (VCE) [l]	2,8	2,4
OCE [ml/kg body weight]	40,4	33,6
Hematocrit [%]	42,8	44,6

So, among untrained people and among representatives of speed-strength sports general content in the blood of hemoglobin is 10-12 g / kg (in women - 8-9 g / kg), and in endurance athletes - g / kg (in athletes - 12 g / kg).

Athletes who train endurance show increased utilization of lactic acid formed in the muscles. This is facilitated by an increased aerobic potential of all muscle fibers and a particularly high percentage of slow muscle fibers, as well as an increased mass of the heart. Slow muscle fibers, like the myocardium, are able to actively use lactic acid as an energy substrate. In addition, with the same aerobic loads (equal consumption of O 2 ) blood flow through the liver in athletes is higher than in untrained, which can also contribute to a more intensive extraction of lactic acid from the blood by the liver and its further conversion into glucose and glycogen. Thus, aerobic endurance training not only increases aerobic capacity, but also develops the ability to perform large long-term aerobic exercise without a significant increase in blood lactic acid.

It is obvious that in winter it is better to do skiing, in the off-season - long distance cross-country running. The lion's share of the physical preparation of those who are going to high mountains should be devoted to these trainings. Not so long ago, scientists broke spears about what kind of distribution of forces when running is optimal. Some believed that the variable, others - uniform. It really depends on the level of training.

Literature

1. Pavlov. - M., "Sails", 2000. - 282 p.

2. Human physiology in high altitude conditions: A guide to physiology. Ed. . - Moscow, Nauka, 1987, 520 p.

3. Khochachka P., Somero J. Biochemical adaptation. M.: Mir, 19s

4. Oxygen transport system and endurance

5. A. Lebedev. Planning sports trips

In the previous chapter, general (i.e., non-specific) patterns of adaptation were analyzed, but the human body responds in relation to specific factors and specific adaptive reactions. It is these reactions of adaptation (to temperature change, to a different mode of motor activity, to weightlessness, to hypoxia, to a lack of information, to psychogenic factors, as well as the features of human adaptation and adaptation management) that are considered in this chapter.

ADAPTATION TO TEMPERATURE CHANGES

The temperature of the human body, like that of any homoiothermic organism, is characterized by constancy and fluctuates extremely narrow borders. These limits range from 36.4 ?C to 37.5 ?C.

Adaptation to the action of low temperature

The conditions under which the human body must adapt to the cold may be different. This can be work in cold shops (cold does not act around the clock, but alternating with normal temperature conditions) or adaptation to life in northern latitudes (a person in the conditions of the North is exposed not only to low temperatures, but also to a changed lighting regime and radiation level).

Work in cold shops. In the first days, in response to low temperatures, heat production increases uneconomically, excessively, and heat transfer is still insufficiently limited. After the establishment of the stable adaptation phase, the processes of heat production are intensified, heat transfers are reduced; eventually an optimal balance is established to maintain a stable body temperature.

Adaptation to the conditions of the North is characterized by an unbalanced combination of heat production and heat transfer. The decrease in heat transfer efficiency is achieved by reducing

and the cessation of sweating, narrowing of the arterial vessels of the skin and muscles. Activation of heat production is initially carried out by increasing blood flow in the internal organs and increasing muscle contractile thermogenesis. emergency stage. An obligatory component of the adaptive process is the inclusion of a stress response (activation of the central nervous system, an increase in the electrical activity of thermoregulation centers, an increase in the secretion of liberins in hypothalamic neurons, in pituitary adenocytes - adrenocorticotropic and thyroid-stimulating hormones, in the thyroid gland - thyroid hormones, in the adrenal medulla - catecholamines, and in their cortex - corticosteroids). These changes significantly modify the function of organs and physiological systems of the body, changes in which are aimed at increasing the oxygen transport function (Fig. 3-1).

Rice. 3-1.Ensuring the oxygen transport function during adaptation to cold

Persistent adaptation accompanied by an increase in lipid metabolism. The content of fatty acids in the blood increases and the level of sugar decreases slightly, fatty acids are washed out of adipose tissue due to increased "deep" blood flow. In mitochondria adapted to the conditions of the North, there is a tendency to uncouple phosphorylation and oxidation, and oxidation becomes dominant. Moreover, there are relatively many free radicals in the tissues of the inhabitants of the North.

Cold water.The physical agent through which low temperature affects the body is most often air, but it can also be water. For example, when in cold water, the cooling of the body occurs faster than in air (water has 4 times more heat capacity and 25 times more thermal conductivity than air). So, in water, the temperature of which is + 12? C, heat is lost 15 times more than in air at the same temperature.

Only at a water temperature of + 33- 35? C, the temperature sensations of people in it are considered comfortable and the time spent in it is not limited.

At a water temperature of + 29.4 ? C, people can stay in it for more than a day, but at a water temperature of + 23.8 ? C, this time is 8 hours and 20 minutes.

In water with a temperature below + 20 ? C, the phenomena of acute cooling quickly develop, and the time of safe stay in it is calculated in minutes.

A person's stay in water, the temperature of which is + 10-12 ? C, for 1 hour or less causes life-threatening conditions.

Staying in water at a temperature of + 1 ? C inevitably leads to death, and at + 2-5 ? C, after 10-15 minutes it causes life-threatening complications.

The time of safe stay in ice water is no more than 30 minutes, and in some cases people die after 5-10 minutes.

The body of a person immersed in water experiences significant overloads due to the need to maintain a constant temperature of the "core of the body" due to the high thermal conductivity of water and the absence of auxiliary mechanisms that provide thermal insulation of a person in the air (the thermal insulation of clothing decreases sharply due to its wetting, thin a layer of heated air near the skin). In cold water, only two mechanisms are left for a person to maintain a constant temperature of the "core of the body", namely: increasing heat production and limiting the flow of heat from the internal organs to the skin.

Limitation of heat transfer from the internal organs to the skin (and from the skin to the environment) is provided by peripheral vasoconstriction, which is most pronounced at the level skin, and intramuscular vasodilation, the degree of which depends on the localization of cooling. These vasomotor reactions, by redistributing the volume of blood towards the central organs, are able to maintain the temperature of the “core of the body”. At the same time, there is a decrease in plasma volume due to an increase in capillary permeability, glomerular filtration, and a decrease in tubular reabsorption.

The increase in heat production (chemical thermogenesis) occurs through increased muscle activity, the manifestation of which is shivering. At a water temperature of + 25 ?C, shivering occurs when the skin temperature drops to + 28 ?C. There are three successive phases in the development of this mechanism:

The initial decrease in the temperature of the "core";

Its sharp increase, sometimes exceeding the temperature of the “core of the body” before cooling;

Reducing to a level dependent on water temperature. In very cold water (below + 10 ? C) trembling begins very abruptly, very intense, combined with rapid shallow breathing and a feeling of compression of the chest.

Activation of chemical thermogenesis does not prevent cooling, but is considered as an "emergency" way to protect against cold. A drop in the temperature of the “core” of the human body below + 35 ?C indicates that the compensatory mechanisms of thermoregulation cannot cope with the destructive effect of low temperatures, and deep hypothermia of the body sets in. The resulting hypothermia changes all the most important vital functions of the body, as it slows down the flow rate chemical reactions in cells. An inevitable factor accompanying hypothermia is hypoxia. The result of hypoxia are functional and structural disorders, which in the absence of the necessary treatment lead to death.

Hypoxia has a complex and diverse origin.

Circulatory hypoxia occurs due to bradycardia and peripheral circulatory disorders.

Hemodynamic hypoxia develops due to the displacement of the oxyhemoglobin dissociation curve to the left.

Hypoxic hypoxia occurs with inhibition of the respiratory center and convulsive contraction of the respiratory muscles.

Adaptation to the action of high temperature

High temperature can affect the human body in different situations (for example, at work, in case of fire, in combat and emergency conditions, in a bath). Adaptation mechanisms are aimed at increasing heat transfer and reducing heat production. As a result, body temperature (although rising) remains within the upper limit of the normal range. The manifestations of hyperthermia are largely determined by the ambient temperature.

When the external temperature rises to + 30-31 ? C, the skin arteries expand and blood flow increases in it, the temperature of the surface tissues increases. These changes are aimed at the release of excess heat by the body through convection, heat conduction and radiation, but as the ambient temperature rises, the effectiveness of these heat transfer mechanisms decreases.

At an external temperature of + 32-33? C and above, convection and radiation stop. Heat transfer by sweating and evaporation of moisture from the surface of the body and respiratory tract acquires leading importance. So, about 0.6 kcal of heat is lost from 1 ml of sweat.

In organs and functional systems during hyperthermia, characteristic shifts occur.

The sweat glands secrete kallikrein, which breaks down a,2-globulin. This leads to the formation of kallidin, bradykinin and other kinins in the blood. Kinins, in turn, provide twofold effects: expansion of the arterioles of the skin and subcutaneous tissue; potentiation of perspiration. These effects of kinins significantly increase the body's heat transfer.

In connection with the activation of the sympathoadrenal system, the heart rate and minute output of the heart increase.

There is a redistribution of blood flow with the development of its centralization.

There is a tendency to increase blood pressure.

In the future, the adaptation is due to a decrease in heat production and the formation of a stable redistribution of the blood filling of the vessels. Excessive sweating turns into adequate at high temperatures. The loss of water and salts through sweat can be compensated by drinking salted water.

ADAPTATION TO THE MODE OF MOTOR ACTIVITY

Often, under the influence of any requirements of the external environment, the level of physical activity changes in the direction of its increase or decrease.

Increased activity

If physical activity becomes high by necessity, then the human body must adapt to a new

condition (for example, to hard physical work, sports, etc.). Distinguish between "urgent" and "long-term" adaptation to increased physical activity.

"Urgent" adaptation - initial, emergency stage of adaptation - characterized by maximum mobilization functional system responsible for adaptation, pronounced stress reaction and motor excitation.

In response to the load, an intense irradiation of excitation occurs in the cortical, subcortical and underlying motor centers, leading to a generalized, but insufficiently coordinated motor reaction. For example, the heart rate increases, but there is also a generalized inclusion of "extra" muscles.

Excitation of the nervous system leads to the activation of stress-realizing systems: adrenergic, hypothalamic-pituitary-adrenocortical, which is accompanied by a significant release of catecholamines, corticoliberin, ACTH and somatotropic hormones. On the contrary, the concentration of insulin and C-peptide in the blood decreases under the influence of exercise.

Stress-realizing systems. Changes in the metabolism of hormones during a stress reaction (especially catecholamines and corticosteroids) lead to the mobilization of the body's energy resources; potentiate the activity of the functional system of adaptation and form the structural basis of long-term adaptation.

stress-limiting systems. Simultaneously with the activation of stress-realizing systems, there is an activation of stress-limiting systems - opioid peptides, serotonergic and others. For example, in parallel with an increase in the content of ACTH in the blood, an increase in the concentration in the blood β endorphins and enkephalins.

Neurohumoral restructuring during urgent adaptation to physical activity ensures the activation of the synthesis of nucleic acids and proteins, the selective growth of certain structures in the cells of organs, an increase in the power and efficiency of the functioning of the functional adaptation system during repeated physical exertion.

With repeated physical exertion, muscle mass increases and its energy supply increases. Along with the

there are changes in the oxygen transport system and the effectiveness of the functions of external respiration and myocardium:

The density of capillaries in skeletal muscles and myocardium increases;

The speed and amplitude of contraction of the respiratory muscles increase, the vital capacity of the lungs (VC), maximum ventilation, oxygen utilization coefficient increase;

Myocardial hypertrophy occurs, the number and density of coronary capillaries increases, the concentration of myoglobin in the myocardium increases;

The number of mitochondria in the myocardium and the energy supply of the contractile function of the heart increase; the rate of contraction and relaxation of the heart increases during exercise, the stroke and minute volumes increase.

As a result, the volume of the function comes in line with the volume of the organ structure, and the body as a whole becomes adapted to the load of this magnitude.

Reduced activity

Hypokinesia (limitation of motor activity) causes a characteristic symptom complex of disorders that significantly limit a person's working capacity. The most characteristic manifestations of hypokinesia:

Violation of the regulation of blood circulation during orthostatic effects;

Deterioration of indicators of efficiency of work and regulation of the oxygen regime of the body at rest and during physical exertion;

The phenomena of relative dehydration, violations of isoosmia, chemistry and tissue structure, impaired renal function;

Atrophy of muscle tissue, impaired tone and function of the neuromuscular apparatus;

Decrease in the volume of circulating blood, plasma and mass of red blood cells;

Violation of the motor and enzymatic functions of the digestive apparatus;

Violation of indicators of natural immunity.

emergencythe phase of adaptation to hypokinesia is characterized by the mobilization of reactions that compensate for the lack of motor functions. Such protective reactions include the excitation of sympathetic

adrenal system. The sympathoadrenal system causes temporary, partial compensation of circulatory disorders in the form of increased cardiac activity, increased vascular tone and, consequently, blood pressure, increased respiration (increased ventilation of the lungs). However, these reactions are short-lived and quickly fade with continued hypokinesia.

The further development of hypokinesia can be imagined as follows:

Immobility contributes, first of all, to the reduction of catabolic processes;

The release of energy decreases, the intensity of oxidative reactions decreases;

The content of carbon dioxide, lactic acid and other metabolic products, which normally stimulate respiration and blood circulation, decreases in the blood.

Unlike adaptation to a changed gas composition, low ambient temperature, etc., adaptation to absolute hypokinesia cannot be considered complete. Instead of the resistance phase, there is a slow depletion of all functions.

ADAPTATION TO WEIGHTLESSNESS

Man is born, grows and develops under the influence of gravity. The force of attraction forms the functions of skeletal muscles, gravitational reflexes, and coordinated muscular work. When gravity changes in the body, various changes are observed, determined by the elimination of hydrostatic pressure and the redistribution of body fluids, the elimination of gravity-dependent deformation and mechanical stress of body structures, as well as a decrease in the functional load on the musculoskeletal system, elimination of support, and changes in the biomechanics of movements. As a result, a hypogravitational motor syndrome is formed, which includes changes in sensory systems, motor control, muscle function, and hemodynamics.

Sensory systems:

Decreased level of reference afferentation;

Decrease in the level of proprioceptive activity;

Change in the function of the vestibular apparatus;

Change in the afferent supply of motor reactions;

Disorder of all forms of visual tracking;

Functional changes in the activity of the otolithic apparatus with a change in the position of the head and the action of linear accelerations.

Motor control:

Sensory and motor ataxia;

spinal hyperreflexia;

Changing the motion control strategy;

Increasing the tone of the flexor muscles.

Muscles:

Decreased speed-strength properties;

Atony;

Atrophy, change in the composition of muscle fibers.

Hemodynamic disorders:

Increased cardiac output;

Decreased secretion of vasopressin and renin;

Increased secretion of natriuretic factor;

Increased renal blood flow;

Decreased blood plasma volume.

The possibility of true adaptation to weightlessness, in which the regulation system is restructured, adequate to existence on Earth, is hypothetical and requires scientific confirmation.

ADAPTATION TO HYPOXIA

Hypoxia is a condition resulting from insufficient oxygen supply to tissues. Hypoxia is often combined with hypoxemia - a decrease in the level of tension and oxygen content in the blood. There are exogenous and endogenous hypoxia.

Exogenous types of hypoxia - normo- and hypobaric. The reason for their development: a decrease in the partial pressure of oxygen in the air entering the body.

Normobaric exogenous hypoxia is associated with the restriction of oxygen supply to the body with air at normal barometric pressure. Such conditions are formed when:

■ presence of people in a small and/or poorly ventilated space (room, shaft, well, elevator);

■ violations of air regeneration and/or supply of oxygen mixture for breathing in aircraft and submersible vehicles;

■ non-compliance with the technique of artificial lung ventilation. - Hypobaric exogenous hypoxia may occur:

■ when climbing mountains;

■ in people raised to great heights in open aircraft, on lift chairs, as well as when the pressure in the pressure chamber is reduced;

■ with a sharp drop in barometric pressure.

Endogenous hypoxia are the result of pathological processes of various etiologies.

There are acute and chronic hypoxia.

Acute hypoxia occurs with a sharp decrease in the access of oxygen to the body: when the subject is placed in a pressure chamber, from where air is pumped out, carbon monoxide poisoning, acute circulatory or respiratory disorders.

Chronic hypoxia occurs after a long stay in the mountains or in any other conditions of insufficient oxygen supply.

Hypoxia is a universal operating factor, to which effective adaptive mechanisms have been developed in the body over many centuries of evolution. The reaction of the body to hypoxic exposure can be considered on the model of hypoxia when climbing mountains.

The first compensatory reaction to hypoxia is an increase in heart rate, stroke and minute blood volumes. If the human body consumes 300 ml of oxygen per minute at rest, its content in the inhaled air (and, consequently, in the blood) has decreased by 1/3, it is enough to increase the minute volume of blood by 30% so that the same amount of oxygen is delivered to the tissues . The opening of additional capillaries in tissues realizes an increase in blood flow, since this increases the rate of oxygen diffusion.

There is a slight increase in the intensity of breathing, shortness of breath occurs only with pronounced degrees of oxygen starvation (pO 2 in the inhaled air is less than 81 mm Hg). This is explained by the fact that increased respiration in a hypoxic atmosphere is accompanied by hypocapnia, which inhibits an increase in pulmonary ventilation, and only

after a certain time (1-2 weeks) of staying in hypoxia, there is a significant increase in pulmonary ventilation due to an increase in the sensitivity of the respiratory center to carbon dioxide.

The number of erythrocytes and the concentration of hemoglobin in the blood increase due to the emptying of blood depots and thickening of the blood, and then due to the intensification of hematopoiesis. Decrease in atmospheric pressure by 100 mmHg. causes an increase in hemoglobin in the blood by 10%.

The oxygen transport properties of hemoglobin change, the shift of the oxyhemoglobin dissociation curve to the right increases, which contributes to a more complete return of oxygen to the tissues.

In cells, the number of mitochondria increases, the content of respiratory chain enzymes increases, which makes it possible to intensify the processes of energy use in the cell.

Behavior modification occurs (limitation of motor activity, avoidance of exposure to high temperatures).

Thus, as a result of the action of all links of the neurohumoral system, structural and functional rearrangements occur in the body, as a result of which adaptive reactions to this extreme impact are formed.

PSYCHOGENIC FACTORS AND DEFICIENCY OF INFORMATION

Adaptation to the effects of psychogenic factors proceeds differently in individuals with different types of GNI (choleric, sanguine, phlegmatic, melancholic). In extreme types (cholerics, melancholics), such adaptation is not stable, sooner or later the factors affecting the psyche lead to a breakdown of the GNA and the development of neuroses.

The following are the main principles of anti-stress protection:

Isolation from the stressor;

Activation of stress-limiting systems;

Suppression of the focus of increased excitation in the central nervous system by creating a new dominant (switching attention);

Suppression of the negative reinforcement system associated with negative emotions;

Activation of the positive reinforcement system;

Restoration of the body's energy resources;

Physiological relaxation.

Information stress

One of the types of psychological stress is informational stress. The problem of information stress is a problem of the 21st century. If the flow of information exceeds the possibilities of the brain formed in the process of evolution for its processing, information stress develops. The consequences of information overload are so great that even new terms are introduced to denote not entirely clear states of the human body: chronic fatigue syndrome, computer addiction, etc.

Adapting to information scarcity

The brain needs not only minimal rest, but also some amount of stimulation (emotionally meaningful stimuli). G. Selye describes this state as a state of eustress. The consequences of a lack of information include a lack of emotionally significant stimuli and growing fear.

The lack of emotionally significant stimuli, especially at an early age (sensory deprivation), often leads to the formation of the personality of the aggressor, and the significance of this factor in the formation of aggressiveness is an order of magnitude higher than physical punishment and other harmful educational factors.

In conditions of sensory isolation, a person begins to experience growing fear up to panic and hallucinations. E. Fromm as one of essential conditions maturation of the individual calls the presence of a sense of unity. E. Erickson believes that a person needs to identify himself with other people (reference group), nation, etc., that is, say "I am like them, they are the same as me." It is preferable for a person to identify himself even with such subcultures as hippies or drug addicts than not to identify himself at all.

sensory deprivation (from lat. sensus feeling, feeling and deprivatio- deprivation) - a prolonged, more or less complete deprivation of a person of visual, auditory, tactile or other sensations, mobility, communication, emotional experiences, carried out either for experimental purposes or as a result of

the current situation. With sensory deprivation, in response to the lack of afferent information, processes are activated that in a certain way affect figurative memory.

As the time spent in these conditions increases, people develop emotional lability with a shift towards low mood (lethargy, depression, apathy), which for a short time are replaced by euphoria, irritability.

There are memory impairments that are directly dependent on the cyclical nature of emotional states.

The rhythm of sleep and wakefulness is disturbed, hypnotic states develop, which drag on for a relatively long time, are projected outward and are accompanied by the illusion of involuntariness.

Thus, the restriction of movement and information are factors that violate the conditions for the development of the organism, leading to the degradation of the corresponding functions. Adaptation in relation to these factors is not of a compensatory nature, since typical features of active adaptation do not appear in it, and only reactions associated with a decrease in functions and ultimately leading to pathology predominate.

FEATURES OF ADAPTATION IN HUMANS

The features of human adaptation include a combination of the development of the physiological adaptive properties of the organism with artificial methods that transform the environment in its interests.

Adaptation Management

Ways to manage adaptation can be divided into socio-economic and physiological.

Socio-economic methods include all activities aimed at improving living conditions, nutrition, and creating a safe social environment. This group of events is extremely important.

Physiological methods of adaptation control are aimed at the formation of nonspecific resistance of the organism. These include the organization of the regime (change of sleep and wakefulness, rest and work), physical training, hardening.

Physical training. The most effective means of increasing the body's resistance to diseases and adverse environmental influences are regular physical exercise. Motor activity affects many systems of life. It extends to the balance of metabolism, activates the vegetative systems: blood circulation, respiration.

hardening. There are measures aimed at increasing the body's resistance, united by the concept of "hardening". A classic example of hardening is constant cold training, water procedures, outdoor charging in any weather.

The dosed use of hypoxia, in particular in the form of a training stay of a person at an altitude of about 2-2.5 thousand meters, increases the nonspecific resistance of the body. The hypoxic factor contributes to an increased release of oxygen to tissues, its high utilization in oxidative processes, the activation of enzymatic tissue reactions, and the economical use of the reserves of the cardiovascular and respiratory systems.

The stress response from the link of adaptation can, under excessively strong environmental influences, transform into a link of pathogenesis and induce the development of diseases - from ulcers to severe cardiovascular and immune diseases.

QUESTIONS FOR SELF-CHECKING

1. What is the adaptation to the action of low temperature?

2. What are the differences between the adaptation to the action of cold water.

3. Name the mechanism of adaptation to high temperature.

4. What is the adaptation to high physical activity?

5. What is the adaptation to low physical activity?

6. Is adaptation to weightlessness possible?

7. What is the difference between adaptation to acute hypoxia and adaptation to chronic hypoxia?

8. Why is sensory deprivation dangerous?

9. What are the features of human adaptation?

10. What ways of managing adaptation do you know?

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