Formation and release of body heat. Heat generation and release Heat is generated to a greater extent
Heat generation, or heat production, is determined by the intensity of metabolism. Regulation of heat production by increasing or decreasing metabolism is referred to as chemical thermoregulation.
The heat generated by the body is constantly released into the external environment surrounding it. If heat transfer did not exist, the body would die from overheating. Heat transfer can increase and decrease. Regulation of heat transfer by changing the physiological functions that carry it out is referred to as physical thermoregulation.
The amount of heat generated in the body depends on the level of metabolism in the organs, which is determined by the trophic function of the nervous system. The greatest amount of heat is generated in organs with intense metabolism - in skeletal muscles and glands, mainly in the liver and kidneys. The smallest amount of heat is released in bones, cartilage and connective tissue.
When the ambient temperature increases, heat generation decreases, and when it decreases, it increases. Consequently, there is an inversely proportional relationship between the ambient temperature and heat generation. In summer, heat generation decreases, and in winter it increases.
The relationship between heat generation and heat transfer depends on the ambient temperature. At an environment of 15-25°C, heat generation at rest in clothing is at the same level and is balanced by heat transfer (zone of indifference). When the ambient temperature is below 15°C, then under the same conditions, heat production increases at 0°C and gradually decreases to 15°C (lower zone of increased metabolism). If the ambient temperature is 25-35°C, the metabolism decreases slightly (low metabolism zone) and thermoregulation is maintained. When the ambient temperature rises above 35°C, thermoregulation is disrupted, metabolism and body temperature increase (upper zone of increased metabolism, overheating zone). Consequently, increasing the temperature of the external environment or warming the body reduces heat production only to a certain level at a certain temperature of the external environment. This temperature is called critical, since its further increase leads not to a decrease, but to an increase in heat generation and an increase in body temperature. In the same way, during cooling, there is a critical temperature of the external environment, below which heat production begins to decrease.
With muscle rest, the increase in heat generation when the body cools is insignificant.
A particularly significant increase in heat generation at low ambient temperatures is observed during trembling and muscle work. Incorrect, small muscle contractions - trembling and increased movements that a person makes in the cold in order to warm up and get rid of chills or trembling, increase trophic functions, significantly increase metabolism and heat production. Heat production also increases slightly with goose bumps - contraction of the muscles of the hair follicles.
It is necessary to take into account that walking increases heat production by almost 2 times, and fast running - by 4-5 times; body temperature can increase by several tenths of a degree, and an increase in temperature during work accelerates oxidative processes and thereby contributes to the oxidation of protein breakdown products. However, with prolonged intensive work at an ambient temperature above 25°C, body temperature can increase by 1-1.5°C, which already causes changes and disruptions in vital functions. When, during muscular work in a high ambient temperature, the body temperature rises to more than 39 ° C, heat stroke may occur. Muscles account for 65-75% of heat generation, and during intensive work even 90%.
The rest of the heat is generated in the glandular organs, mainly in the liver.
The body at rest continuously loses heat: 1) by heat radiation, or heat transfer from the skin to the surrounding air; 2) heat conduction, or direct heat transfer to those objects that come into contact with the skin; 3) evaporation from the surface of the skin and lungs.
Under resting conditions, 70-80% of the heat is released into the environment by the skin by heat radiation and heat conduction, and about 20% by evaporation of water in the skin (sweating) and in the lungs. Heat transfer by heating exhaled air, urine and feces is negligible, it accounts for 1.5-3% of the total heat transfer.
During muscular work, the release of heat by evaporation increases sharply (in humans, mainly by sweating), reaching 90% of the total daily heat generation.
Heat transfer by heat radiation and heat conduction depends on the temperature difference between the skin and the environment. The higher the skin temperature, the greater the heat transfer through these pathways. The temperature of the skin depends on the flow of blood to it. When the ambient temperature increases, the arterioles and capillaries of the skin. But since the difference in skin temperature decreases, the absolute value of heat transfer at high ambient temperatures is less than at low ones.
When the skin temperature is compared with the ambient temperature, heat transfer stops. With a further increase in ambient temperature, the skin not only does not lose heat, but itself heats up. In this case, heat transfer by heat radiation and heat transfer is absent and only heat transfer by evaporation is retained.
On the contrary, in the cold, the arterioles and capillaries of the skin narrow, the skin becomes pale, the amount of blood flowing through the dog decreases, the skin temperature drops, the temperature difference between the skin and the environment is smoothed out, and heat transfer decreases.
A person reduces heat transfer with artificial coverings (underwear, clothing, etc.). The more air there is in these covers, the easier it is to retain heat.
Regulation of heat transfer by water evaporation plays an important role, especially during muscular work and a significant increase in ambient temperature. When 1 dm 3 of water evaporates from the surface of the skin or mucous membranes, 2428.4 kJ is lost by the body.
Loss of water from the skin occurs due to the penetration of water from deep tissues to the surface of the skin and mainly due to the functioning of the sweat glands. At average ambient temperature, an adult loses 1674.8-2093.5 kJ daily by evaporation from the skin.
Due to the sharp increase in sweating with increasing ambient temperature and during muscular work, heat transfer also increases significantly, although not all sweat evaporates.
Large losses of sweat are accompanied by losses of large amounts of mineral salts, since the content of table salt alone in sweat is 0.3-0.6%. With a loss of 5-10 dm3 of sweat, 25-30 grams of table salt are lost. Therefore, if the thirst that arises from profuse sweating is satisfied with water, then severe disorders occur due to the loss of significant amounts of salts (convulsions, etc.). Already with the loss of 2 dm 3 of sweat, a deficiency of salts in the body results. These losses are replenished by drinking water containing 0.5-0.6% table salt, which is recommended to drink during profuse, prolonged sweating.
Water evaporation constantly occurs from the surface of the lungs. The exhaled air is saturated with water vapor by 95-98% and therefore the drier the inhaled air, the more heat is given off by evaporation from the lungs. Under normal conditions, the lungs evaporate 300-400 cm 3 of water every day, which corresponds to 732.7-962.9 kJ. At high temperatures, breathing becomes more frequent, and in the cold it becomes rare. Evaporation of water from the surface of the skin and lungs becomes the only way of heat transfer when the air temperature reaches body temperature. Under these conditions, more than 100 cm 3 of sweat per hour evaporates at rest, which allows you to release about 251.2 kJ per hour.
The evaporation of water from the surface of the skin and lungs depends on the relative humidity of the air. It stops in air saturated with water vapor. Therefore, being in humid hot air, such as a bathhouse, is difficult to tolerate. A person feels unwell in damp air, even at a relatively low ambient temperature - at 30°C. Leather and rubber clothing is poorly tolerated, as it is impermeable to and makes it impossible for sweat to evaporate, so sweat accumulates under such clothing. With high air temperatures and muscle work in leather and rubber clothing, a person’s body temperature rises.
Overheating a person in a room saturated with water vapor is especially dangerous, as it makes it impossible to get rid of excess heat in the most effective way - evaporation.
On the contrary, in dry air a person can relatively easily tolerate a much higher temperature than in humid air.
Air movement is of great importance for increasing heat transfer by heat radiation, heat conduction and evaporation. Increasing the speed of air movement increases heat transfer. In a draft and wind, heat loss increases sharply. But if the surrounding air has a high temperature and is saturated with water vapor, then air movement does not cool. Consequently, physical thermoregulation is provided by: 1) the cardiovascular system, which determines the inflow and outflow of blood in the blood vessels of the skin, and, consequently, the amount of heat given off by the skin to the environment; 2) the respiratory system, i.e. changes in pulmonary ventilation; 3) changes in the function of the sweat glands.
Heat transfer is regulated by the nervous system and through hormones. Conditioned reflexes to environments in which the body has been repeatedly heated or cooled are essential.
Changes in the functions of the cardiovascular system, respiration and sweat glands are reflexively regulated by irritation of external sensory organs and especially irritation of skin receptors with changes in external temperature, as well as irritation of the nerve endings of internal organs with fluctuations in temperature inside the body. Physiological mechanisms of physical thermoregulation are carried out by the cerebral hemispheres, intermediate, medulla oblongata and spinal cord.
Heat transfer changes when hormones enter, changing the functions of organs involved in physical thermoregulation.
In accordance with the laws of thermodynamics, metabolic and energy processes are associated with the production of heat. In some animals (and humans), body temperature remains at a constant level, which significantly exceeds the temperature of the environment due to intensive heat production controlled by special regulatory mechanisms. This - homeothermic (warm-blooded)) organisms. Another group of animals (fish, amphibians) is characterized by a significantly lower intensity of heat production; their body temperature only slightly exceeds the temperature of the environment and undergoes the same fluctuations ( poikilothermic, cold-blooded animals).
Heat production and body temperature. All chemical reactions in the body depend on temperature. In poikilotherms, the intensity of energy processes increases in proportion to the external temperature in accordance with Van Hoff's rule. In homeothermic animals, this rule is masked by another effect (regulatory thermogenesis) and appears only when thermoregulation is blocked (anesthesia, damage to the nervous system). Even after blockade of the regulatory component, significant quantitative differences remain between metabolic processes in cold-blooded and warm-blooded animals: at the same body temperature, the intensity of energy exchange per unit of body mass in warm-blooded animals is 3 times greater. Anesthesia, together with a decrease in body temperature, can cause a noticeable decrease in the degree of oxygen consumption and a delay in the processes of tissue destruction - this is used in surgery.
Heat production and body size. The body temperature of most warm-blooded animals lies in the range of 36-39 ° C, despite significant differences in weight and size. In contrast, metabolic rate (M) is a power function of body weight (m): M = km 0.75. The coefficient k is approximately the same for both a mouse and an elephant. This law of the dependence of metabolism on body weight reflects the tendency to establish a correspondence between heat production and the intensity of heat transfer into the environment. The greater the ratio between the surface and volume of the body, the greater the heat loss per unit mass, and this ratio decreases with increasing body size. In addition, in small animals the insulating layer of the body is thinner. If you arrange some animals in order of decreasing intensity of metabolic processes, you get the following: mouse, rabbit, dog, human, elephant.
Thermoregulatory thermogenesis. When additional heat is needed to maintain body temperature, it can be generated in the following ways:
1. Voluntary activity of the muscular system.
2. Involuntary tonic or rhythmic (tremor) activity. These two pathways are called contractile thermogenesis.
3. Acceleration of metabolic processes not associated with muscle contraction (not contraction)
body thermogenesis).
In an adult, shivering is the most significant involuntary manifestation of thermogenesis mechanisms. In a newborn baby, it is not contractile thermogenesis (the combustion of brown fat in the “metabolic cauldron”) that is of greater importance. Accumulations of brown fat with a large number of mitochondria are located between the shoulder blades, in the armpit. As the body cools, its temperature increases and blood flow increases. By increasing thermogenesis, body temperature is maintained at a constant level.
Environmental factors and thermal comfort. The effect of environmental temperatures on the body depends on at least four physical factors: air temperature, humidity, radiation temperature and air speed (wind). These factors determine whether a person feels "thermal comfort" or feels hot or cold. The condition of comfort is that the body does not need the functioning of thermoregulation mechanisms: it does not require any trembling or sweating, and the blood flow in the peripheral areas maintains an average speed. This is the so-called thermoneutral zone.
These four factors are to some extent interchangeable.
The comfort temperature value for a lightly dressed (shirt, shorts, long cotton trousers) seated person is 25-26 o C with a humidity of 50% and equal air and wall temperatures. For a naked person = 28 o C. Under conditions of thermal comfort, the average skin temperature = 34 o C. As physical work is performed, the comfort temperature drops. For light office work it is 22 o C.
Discomfort increases with the average temperature and humidity of the skin (the part of the body surface covered with sweat).
Heat dissipation.
1. Internal heat flow. Less than half of all heat generated inside the body spreads to the surface by conduction through tissue. Most of it goes by convection into the bloodstream. Blood has a high heat capacity. The blood flow of the extremities is organized according to the principle of a rotary-countercurrent mechanism, which facilitates heat exchange between the vessels.
2. External heat flow.
Heat is transferred outwards through conduction, convection, radiation and evaporation. Heat transfer by conduction is when a body comes into contact with a dense substrate. When body contact occurs with air - convection, radiation or evaporation. If the skin is warmer than the air, the adjacent layer heats up and moves upward, being replaced by colder air. Forced convection (blowing) significantly increases the intensity of heat transfer. The radiation occurs in the form of long-wave infrared radiation. About 20% of the heat transfer of the human body in neutral temperature conditions occurs due to the evaporation of water from the skin and mucous membranes of the respiratory tract.
The influence of clothing - from a physiological point of view, it is a form of thermal resistance or insulation. The effectiveness of clothing is determined by the smallest volumes of air in the structure of the fabric or in the pile, where external currents do not penetrate. In this case, heat is transferred only by conduction, and air is a poor conductor of heat. Body temperature and heat balance
. If it is necessary to maintain body temperature constant, a stable balance must be achieved between heat production and heat transfer. When the environmental temperature decreases, a constant body temperature can be maintained only if regulatory mechanisms ensure an increase in thermogenesis in proportion to heat loss. The highest heat production provided by these mechanisms in humans corresponds to basal metabolic rates 3–5. This indicator characterizes the lower limit of the thermoregulation range (0-5 o C in the external environment for adults, 23 o C for newborns). If this limit is exceeded, hypothermia and cold death develop.
With an increase in the temperature of the environment, the skin vessels dilate, the total amount of circulating blood increases due to its exit from the depot, due to the entry of water from the tissues. This promotes increased heat transfer. But the main thing is still evaporation. The average heat generation per day during vigorous activity is about 2500-2800 kcal. To maintain body temperature at a constant level under these conditions, it is necessary to evaporate 4.5 liters of water. For heavy muscular work - up to 12 liters. in a day. Water evaporation depends on the relative humidity of the air in the room and is impossible at 100% humidity. Therefore, high humidity at high temperatures is poorly tolerated. In this case, sweat does not evaporate, but flows off the skin. This type of sweating does not contribute to the transfer of heat. Clothing that is impervious to air (leather, rubber) is also poorly tolerated, as it prevents evaporation. In completely dry air, a person does not overheat in 2-3 hours at T 55 o C.
Human body temperature. The heat generated in the body is transferred to the surrounding space by the surface of the body. Therefore, T about the surface is less than T about the core of the body, and T about the distal part of the limbs is less than the proximal one. In this regard, the spatial distribution of body temperature has a complex three-dimensional shape. For example, when a lightly dressed adult is in a room with an air temperature of 20 o C, in the deep muscles of his thigh the temperature is 35 o C, in the calf muscle - 33 o C, on the foot - 27 o C, in the rectum -37 o C.
Fluctuations in body temperature with changes in external temperature are more pronounced near the surface of the body and in the end parts of the limbs. There is a “homeothermic core” and a “poikilothermic shell”.
Core body temperature itself is not constant either spatially or temporally. The differences are 0.2-1.2 o C. Even in the brain, the temperature of the center and cortex differs by 1 o. As a rule, the highest T o is observed in the rectum (and not in the liver, as was previously believed!). In this regard, it is impossible to express the T about the body in one number. For practice, it is enough to find a certain area in which T o can be considered as representative of the entire internal layer. Clinical measurements require an easily accessible area with minor spatial temperature variations. In this sense, it is preferable to use rectal temperature. In this case, a special rectal thermometer is inserted at 10-15 cm. Normally, it is 37 o C.
Oral temperature (sublingual) is also used clinically. Usually it is 0.2-0.5 o less than rectal.
Axillary temperature (most often used in Russia) is 36.5-36.6 o. Can serve as an indicator of core body temperature because when the arm is pressed tightly against the chest, the temperature gradient shifts so that the boundary of the body's core reaches the armpit. However, you have to wait quite a long time (10 minutes) until enough heat accumulates in these areas. If the superficial tissues were initially cold in conditions of low ambient temperature and vasoconstriction occurred in them, then about half an hour should pass for the appropriate equilibrium to be established in these tissues.
Periodic fluctuations in core temperature. During the day, a person's minimum temperature is observed in the pre-dawn hours, and the maximum in the afternoon. The amplitude of the oscillations is 1 o C. The daily (circadian) rhythm is based on an energy mechanism (biological clock), which is usually synchronized with the rotation of the earth. In conditions of travel associated with crossing the earth's meridians, it takes 1-2 weeks for the temperature regime to come into line with the conditions of the new local time. Circadian rhythms are superimposed on others (menses in women, etc.).
The temperature during physical activity can increase by 2 ° C or more, depending on the intensity of the activity. At the same time, the average skin temperature decreases, as sweat is released due to the work of the muscles, which cools the skin. Rectal temperature during work can reach 41 o (for marathon runners).
Skin blood vessels can respond directly to changes in T - so-called. cold expansion, which is due to the local thermosensitivity of the vascular muscles. Cold dilation of blood vessels is usually observed in the form of the following reaction. When a person is exposed to extreme cold, he first experiences maximum vasoconstriction, which manifests itself in pallor and a feeling of cold in exposed areas. However, after some time, blood suddenly rushes into the vessels of the cooled parts of the body, which is accompanied by redness and warming of the skin. If exposure to cold continues, the events repeat periodically.
Cold vasodilation is thought to be a protective mechanism to prevent frostbite, especially in cold-adapted individuals. However, this mechanism can precipitate the death of general hypothermia in those who are forced to swim in cold water for a long time.
When water plays the role of the environment, since it has greater thermal conductivity and heat capacity than air, more heat is removed from the body by convection. If the water is in motion, then heat is removed so quickly that at an ambient temperature of +10 o C, even strong physical work does not allow maintaining thermal equilibrium, and hypothermia occurs. If the body is at complete rest, then to achieve temperature comfort, the temperature of the water should be 35-36 o. The lower limit of the thermoneutral zone depends on the thickness of the adipose tissue.
Mechanisms of thermoregulation. Thermoregulatory reactions are reflexes carried out by the central nervous system. They arise in response to stimulation of thermoreceptors in the periphery and in the central nervous system itself. There are two types of thermoreceptors - some perceive heat (heat receptors), others perceive cold (cold receptors). Both react with the appearance of a flash of impulses in response to adequate stimulation (a corresponding change in the temperature of the environment), and what matters is the rate of temperature change and the magnitude of the stimulus (the difference between the initial and new temperatures in the tissues).
Temperature receptors in the central nervous system are located in the preoptic zone of the anterior part of the hypothalamus, in the reticular formation of the midbrain and in the spinal cord. The presence of such receptors is proven by the appearance of tremors in the dog when the denervated limb cools. Local cooling of different parts of the brain causes bursts of impulses.
Thermoregulation centers are located in the hypothalamus. Its destruction makes the animal poikilothermic. Removal of other parts of the brain does not significantly affect the processes of heat generation and heat transfer. There are cores for heat transfer and heat production. It has been shown that the processes of physical thermoregulation are regulated mainly by the anterior hypothalamus, and chemical thermoregulation by the caudal nuclei. Both centers are in complex reciprocal relationships.
The executive mechanisms of the functional system for maintaining a constant body temperature (FST) are all those organs that can provide two normally mutually balanced processes of heat production and heat transfer, as well as special adaptive behavior.
The endocrine system is also involved in temperature regulation. Thus, thyroxine increases the intensity of metabolism, increasing heat production. Adrenaline constricts blood vessels, maintaining core body temperature.
Ontogenesis of thermoregulation. In immature-bearing animals, newborns are not capable of thermoregulation and are actually poikilothermic (gophers, hamsters, etc.). In other animals and in humans, all themoregulatory reactions (increased thermogenesis, vasomotor activity, sweat, behavior) can be turned on immediately after birth to one degree or another. This applies even to premature babies weighing about 1000 g. It is widely believed that newborns have an immature hypothalamus, responsible for thermoregulation. However, the newborn meets its needs through non-contractile thermogenesis. Children's heat production increases by 200% without shivering.
The small size of the newborn is a disadvantage in terms of thermoregulation. The ratio between body surface and volume is 3 times that of an adult, and the fat layer is small. Therefore, per unit mass of heat, children produce 4-5 times more heat. The upper limit of the thermoneutral zone of newborns is 32-34 o, the lower limit is 23 o C. Within this limited range, a newborn is able to maintain a constant temperature.
Thermal adaptation. The most important feature that occurs during thermal adaptation is the change in the intensity of sweat secretion, which can increase 3 times and reach 4 l/h for short periods. During adaptation to high temperatures, the electrolyte content in sweat decreases significantly to avoid loss of salts.
One of the main adaptive changes is the increase in thirst for a given level of water loss as thermal adaptation develops. This is necessary to maintain water balance.
In addition, threshold temperatures for associated vasomotor responses and sweating vary in different directions depending on whether the heat exposure is acute, chronic, moderate, or severe. Thus, 4-6 days after a daily 2-hour heat stress with maximum sweat production (sauna), reactions of sweat secretion and vasodilation occur at internal temperatures 0.5 o lower than before. The biological significance of the threshold shift is that, due to adaptation, the body temperature at a given heat load decreases, so that the body is protected from a critical increase in heart rate and blood flow - reactions that can lead to heat syncope.
In contrast, in persons living long-term in the tropics (chronic mild heat shift), the core temperature at rest is higher, and the reactions of sweating and vasodilation begin at a body temperature 0.5 ° C higher than in a temperate climate. This type of thermal adaptation is called adaptive endurance.
Hyperthermia. Hyperthermia occurs when the temperature in the armpit rises to more than 37 o C. The maximum body temperature for survival is + 42 o C (very briefly 43 o). At the same time, all thermoregulatory processes are extremely tense. Under conditions of prolonged heat stress at temperatures above 40-41 o, severe brain damage occurs - “heat or sunstroke”. Heat syncope with relatively mild overheating in people with impaired cardiovascular system functions is more dependent on circulatory failure than on thermoregulation mechanisms.
Fever. Fever develops as a result of increased heat production through shivering and maximum vasoconstriction in the peripheral parts of the body, i.e. the body behaves as if it were at a low ambient temperature. During the recovery period, the opposite process occurs - with the help of sweat and vasodilation, the body temperature drops in the same way as when a person has a fever. In this case, a person can correctly respond to true changes in external temperature. The mechanism for the appearance of a febrile reaction is associated with the release of leukocyte and bacterial pyrogens onto the central thermoregulatory apparatus.
Cold adaptation. Fur, fat layer, brown fat are all types of cold adaptation mechanisms in different animals. These mechanisms are not characteristic of an adult, so you can often hear the opinion that adults are not capable of any physiological adaptation to cold; they should rely only on behavioral adaptation (clothing and warm homes). It is said that man is a “tropical creature” who can survive in the Arctic only due to his civilization.
However, it has been shown that in cases of prolonged exposure to cold, people develop tolerance (endurance) to the cold. The threshold for the development of tremors and changes in metabolic thermoregulatory reactions shifts towards lower temperatures. In this case, even moderate hypothermia may occur. Similar tolerance is observed among the aborigines of Australia, who can spend a whole night almost naked without shivering at an ambient temperature of about 0 o C, as well as among Japanese divers, who spend several hours in water of about 10 o C. The same applies to ours. walruses."
It was shown that the shivering threshold could be shifted toward lower temperatures over just a few days during which subjects were subjected to repeated cold stress. With prolonged exposure (Eskimos, residents of Patagonia), the intensity of the basal metabolism increases by 25-50% - this is a metabolic adaptation.
Local adaptation. If the hands of a warmly dressed person are regularly cooled, then pain in the hands decreases. This is due to the fact that cold expansion of blood vessels occurs at a higher room temperature.
Hypothermia. Hypothermia occurs when the armpit temperature drops below 35°. This happens faster when immersed in cold water. In this case, a state similar to anesthesia is observed - the disappearance of sensitivity, weakening of reflex reactions, decreased excitability of the central nervous system, metabolic rate, slowing of breathing and heart rate, and a drop in blood pressure. This is the basis for the use of artificial hypothermia, which reduces the brain's need for oxygen, making longer bleeding during operations on the heart and large vessels tolerable. Now there are known cases of heart shutdown during hypothermia for 40-60 minutes (Vereshchagin). Hypothermia is stopped by quickly warming the body. Artificial hypothermia is carried out when the thermoregulatory mechanisms are turned off.
In old age, hypothermia develops due to overregulation of temperature reactions - normally the body temperature reaches 35 o (a phenomenon opposite to fever).
A decrease in body temperature to 26-28 o causes death from cardiac fibrillation.
About the author of books and articles: doctor, leading acupuncturist of Belarus, candidate of medical sciences, Molostov Valery Dmitrievich, published 23 books in Moscow and Minsk (on neurology, acupuncture, massage, manual therapy and on the aging of society as an organism), home phone: Minsk, (8---107 -375-17) 240–70–75, E-mail: [email protected]. My page on the Internet: www.molostov-valery.ru, where books are posted (previously published in Moscow and Minsk) with a detailed justification for the real existence of the idea described here.
Which organ of the human body produces heat?
Every person knows well that our body temperature is 36.6 degrees Celsius. But for a long time medicine has not resolved the question of which organ produces heat in animals, including humans. Finally, Russian physiologists have found the answer to this question. (For example, read the research of Dr. Molostov). It turns out that heat is produced by only one organ - the skin. And heat is produced by acupuncture points into which acupuncturists love to insert needles. A very unexpected discovery for the entire world of science was research on the physiological role of acupuncture points. Not a single scientist in the world in other countries (even in the USA, Germany and France) has engaged in such research.
Picture 1.
This article is dedicated to acupuncture points, about which I can tell a lot of interesting things, since I am a professional acupuncturist by profession. See Figure 1. There are 3,478 acupuncture points found on human skin. By the way, the number of acupuncture points in a cat, cow, elephant, ram, dog, chicken, elephant, bison is exactly the same - 3478 acupuncture points. And acupuncture points in animals are located anatomically exactly where they are in humans. It can be assumed that all warm-blooded animals on Earth have some common ancestor, for example, some kind of marine ichthyosaur. It is interesting to note that all “warm-blooded” animals have acupuncture points, and all cold-blooded animals (worms, frogs, fish, snakes) do not have acupuncture points on the surface of their skin. See Figure 2 and 3.
Figure 2. Warm-blooded.
Figure 3. Cold-blooded.
What is the mechanism of heat generation (production) in warm-blooded animals? It turns out that the energy “substance” for generating heat inside acupuncture points is the electricity that is generated in the body of the animal itself and the person. Physiology claims that many animal and human organs play the role of small power plants. The largest generators of electricity are the heart (produces 60% of the electricity) and the brain (generates 30% of the electricity). The five senses also produce electricity: vision, hearing, touch, smell, and taste. They also work like microscopic power plants, but they transform light, sound and chemical energies into electrical potentials of a specific wavelength. How does the eye generate electricity? Light enters the retina of the eye, where it is transformed into a continuous stream of electrical impulses entering through the optic nerve into the visual centers of the cerebral cortex. The same transformers (not generators) of electrical energy are other sense organs: ears, tactile glomeruli of the skin, olfactory bulbs in the nasal mucosa, taste nerve networks in the mucous membrane of the tongue.
What is the fate of the electrons produced by the heart, brain and five senses? It turns out that there is a very strange pattern: only 5% of the electrical energy they produce is absorbed by all electricity generators. The remaining 95% of the electrical energy from these organs travels through the intercellular space to the skin and acupuncture points. Static electricity covers the entire surface of the skin. On the surface of the skin, electricity “spreads”, just as the waters of the ocean spread over the surface of the Earth. Next, acupuncture points absorb static currents, which cover the skin with a “thin layer”, burning them in their “furnaces” " See Figure 4. The “burning of electrons” produces heat for the human body in the amount of 36.6 degrees Celsius.
Figure 4. Electrons are absorbed by an acupuncture point.
Figure 5. Acupuncture.
This is the mechanism for producing heat by the body of our body and the body of an animal. True, the question remains unanswered: why does a person have a normal body temperature, which is exactly plus 36.6º Celsius? Medical science cannot answer the question “Why does inserting needles into acupuncture points have a healing effect on a person?” See Figure 5. This problem has not yet been studied either. Let's hope that in the next decade scientists will find the answer to these questions. By the way, stopping the activity of electricity generators in the human body is the only cause of natural death of an absolutely healthy, but very old person. It turns out that in old people, the production of electrical energy in the brain and heart first decreases and then stops. See Figure 6. The death of the old organism occurs at the moment when the “power plants” in the heart (Ashof-Tavarovsky node) and in the brain (reticuloendothelial formation) stop generating electricity.
Figure 6. Old man.
Then breathing and heartbeat immediately stop, and death occurs. It is for this reason that absolutely healthy, but very old people, over 100 years old, die. Knowing this information, you can easily extend the life of old people: you need to insert small electrical generators into the heart and brain - and the person will live forever. After all, as long as the heartbeat and breathing continue, the body will live. A healthy brain, liver, kidneys, stomach, intestines and other organs can function for a millennium.
WARM-BLOODED AND COLD-BLOODED ANIMALS
In the process of evolutionary development, mammals, birds and humans have developed the ability to constantly maintain the same body temperature. Regardless of the temperature of the external environment, that is, both in heat and cold, the body temperature of this group of animals and humans does not change, but is maintained at the same level. This ability to maintain a constant temperature creates more constant conditions important for the normal functioning of the body and makes it relatively less dependent on environmental conditions.
Animals whose bodies, thanks to the presence of a number of adaptations, maintain a constant temperature are called warm-blooded (homeothermic). Humans are also warm-blooded.
Invertebrate animals and a significant part of vertebrates do not have a constant temperature. The body temperature of these animals depends on the temperature of the environment where they are located. If the ambient temperature decreases, the body temperature of these animals decreases, and, conversely, an increase in environmental temperature leads to an increase in the body temperature of these animals. This group of animals is called cold-blooded (poikilothermic). Their body is deprived of devices that would make it possible to regulate its own temperature.
The intensity of life processes occurring in the body of these animals is subject to fluctuations and depends on the ambient temperature. The significance of this circumstance can be illustrated by the example of a frog: in winter, when its body temperature is close to 0°, it jumps to a distance of 10-15 cm; in the summer, when her body temperature rises to 20-25°, her jumps even exceed 100 cm.
HEAT FORMATION IN THE BODY
Heat in the body is formed as a result of the oxidation of nutrients to their final products of breakdown. The place where heat generation mainly occurs ismuscles. Heat formation occurs in the muscles even when a person is at complete rest. Minor muscle movements already contribute to greater heat generation, and when walking, heat generation increases by 60-80%. During muscle work, heat generation increases 4-5 times. In addition to skeletal muscles, heat generation occurs in the liver, kidneys and other organs. The liver temperature is highest. Compared to other organs (per unit weight), more heat is generated in it.
The formation of heat in the body is accompanied by its release. The body loses as much heat as it produces. Heat does not stay in the human body, otherwise he would die within a few hours.
These complex processes of regulation of the formation and release of heat by the body are called thermoregulation and are carried out by a number of adaptive mechanisms, for considerationwhich we will move on to.
REGULATION OF HEAT GENERATION AND HEAT TRANSFER
Body temperature remains constant due to the fact that, through a number of mechanisms in the body, the central nervous system regulates both the formation and release of heat.
Oxidative processes occur in the cells and organs of our body, which are accompanied by the release of energy. A change in the intensity of oxidative processes, and therefore the intensity of energy release, entails a change in heat generation.
Heat is consumed by the body in different ways. The main ways of heat transfer are: heat loss by conduction, i.e. heating, of the surrounding air and radiation; in addition, heat is consumed with exhaled air, with the evaporation of sweat, etc.
Consequently, the body temperature of warm-blooded animals remains constant due to the fact that the nervous system regulates, on the one hand, the intensity of oxidative processes, i.e., heat formation, and, on the other, the intensity of heat transfer. These interrelated processes, called chemical and physical thermoregulation, are caused by the activity of the central nervous system.
Chemical thermoregulation. Chemical thermoregulation is understood as a change in metabolic rate that occurs under the influence of the environment. Changes in ambient temperature are detected by the skinThe intensity of metabolism, i.e., heat generation, changes reflexively and by receptors. There is, for example, a certain relationship between air temperature and metabolism in the body. Thus, as the air temperature decreases, the formation of heat in the body increases.
Most of the heat is generated in the muscles. One of the adaptive mechanisms is muscle tremors that occur in the cold. The shivering that occurs when the body cools down is the result of a reflex. When the ambient temperature drops, skin receptors that perceive temperature stimulation are irritated; excitation arises in them, which goes to the central nervous system and from there to the muscles, causing periodic contractions.
Thus, the trembling and chills that we experience during the cold season or in a cold room are reflex acts that contribute to increased metabolism and, consequently, increased heat production.
Increased metabolism occurs under the influence of cold, even when there is no muscle movement. This was shown experimentally when the animal was cooled. It turned out that if the animal is cooled, it intensifies regardless of whether trembling occurs or not.
A significant amount of heat is also generated in the abdominal organs - the liver and kidneys. This can be monitored by measuring the temperature of the blood flowing into the liver and the temperature of the blood flowing out. It turns out that the temperature of the outflowing blood is higher than the temperature of the inflowing blood. Consequently, it warmed up when flowing through the liver
As air temperature rises, heat generation in the body decreases.
Article on the topic Formation and release of body heat
