Socio-biological foundations of physical culture. Social foundations of physical culture

Physical culture and sports in society is an important factor in the comprehensive development and education of a person, strengthening his health, and increasing efficiency.

To solve the problems of physical improvement of people, it is necessary to train highly qualified personnel - teachers and trainers. Physical education, sports training are, first of all, social and pedagogical processes, which determines the leading role of the teacher. However, the object of these processes is a person with all the complexity of the functions of his body, psyche, interaction with the environment. Therefore, the effectiveness of physical culture and sports classes largely depends on the system of correspondence of the means and methods of training used to the functional capabilities, individual characteristics of each student. Only with such compliance can the health-improving effect of training, high and stable sports results be achieved.

This is especially important in modern conditions, when more and more masses of people of different ages, health levels, preparedness, and various professions are involved in physical culture and sports.

Human health is defined as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". Taking into account the social essence of a person, health is also defined as “the life of an able-bodied person adapted to changes in the environment” (I.R. Petrov). It should also be added that the maximum possible range of adaptation for a given person can be significantly expanded due to hardening, systematic physical exercises and other influences.

The human body can be considered as a single self-developing biological system in which all processes and organs are interconnected.

The reaction of the body to the action of factors harmful to it, characterized by a limitation of adaptability and vital activity, is a disease.

Local and general changes in the disease become understandable in their relationship based on the principles of nervosa and the integrity of the organism. From the same theoretical positions, any disease is a suffering of the whole organism. But the ratio of local and general changes in diseases can be very diverse. In some cases, general disorders in the body cause local lesions of various localization and severity: for example, negative emotions, disrupting the nervous regulation of functions, can lead to ulcers of the gastrointestinal tract and myocardial infarction. In other cases, initially localized damage can cause severe general disorders: for example, with tonsillitis, microbes from the tonsils can enter the general circulation and cause infection of various organs (often fatal).

Local general disorders during illness mobilize various defense mechanisms aimed at eliminating functional and structural disorders, at restoring the constancy of the internal environment of the body.

Protective reactions are aimed at stopping the action of a constant stimulus (for example, withdrawing a hand from a hot object), removing harmful substances from the body (vomiting with food poisoning), or destroying them.

The barrier function is performed, for example, by the skin and mucous membranes. They are mechanical obstacles for microbes. Many secrets secreted by the glands on the surface of the barriers have an antimicrobial effect (mesozyme of saliva, lacrimal fluid, hydrochloric acid of the stomach, etc.). Complex is the so-called blood-brain barrier that protects the central nervous system. The most important barrier function in tissue damage is played, in particular, by the evolutionarily developed inflammatory process.

From what has been said, it follows that barriers either prevent damage in the body or prevent its further spread.

Adaptive reactions develop in response to disorders that occur during illness and ensure the unity of the organism with the external environment at a new level of its vital activity. Active adaptation in response to the action of a pathogenic factor is characterized by the mobilization of functional reserves of the most important life-supporting systems, a high level of energy consumption and the vital activity of the organism.

When the body cannot energetically provide an active adaptation in response to the action of external factors (very large blood loss, severe trauma), another universal defense mechanism comes into play - a passive adaptation. It is based on the transcendent, protective inhibition of the central nervous system, in which the existence of a diseased organism is ensured by a sharp decrease in its energy consumption.

Compensatory mechanisms are activated in case of persistent violation or loss of any functions. So, when one of the paired organs (kidneys, adrenal glands) is removed, the function of the remaining organ increases. The nervous system plays a leading role in the mobilization of all forms of protection.

The functional state of the body of athletes is studied in the process of in-depth medical examination. To judge the functional state of the body, all methods are used, including instrumental ones, adopted in modern medicine. At the same time, the functioning of various systems is studied and a comprehensive assessment of the functional state of the organism as a whole is given.

To study the functional state of the athlete's body systems, he is examined at rest and under conditions of various functional tests. The data are compared with normal standards obtained from the examination of large contingents of healthy people not involved in sports. In the process of such a comparison, either compliance with normal standards or deviation from them is established. The deviation is most often the result of those functional changes that develop during sports training (for example, slowing the heart rate in well-trained athletes). However, in some cases it may be due to fatigue, exercise, or illness.

An obligatory process, without which life is unthinkable, is metabolism. It is possible only under the condition of free energy costs, i.e. when doing work.

Metabolism (metabolism) is a process of assimilation (anabiosis) and dissimilation that is simultaneous, but equally proceeding in intensity.

Due to assimilation, there is an accumulation of plastic substances that are used to form various tissues of the body (body mass), and energy substances necessary for the implementation of all life processes, including movement.

Due to dissimilation, chemical substances break down, the tissue elements of the body (old, dead and damaged) are destroyed and energy is released from the energy substances accumulated in the process of assimilation.

Both processes are carried out subject to the receipt, processing and assimilation of plastic and energy substances (proteins, fats and carbohydrates), vitamins, minerals and trace elements from the external environment in the form of food, as well as the removal of decay products from the body. This or that course of metabolism depends on the relationship of the organism with the environment that develops at each individual moment.

The influence of the environment on the body is multifaceted. It is the supplier of all the substances necessary for its life and development, it also serves as a source of a constant and countless flow of disturbing influences (irritations). The existence of an organism under these conditions is possible only if it promptly responds to all influences with appropriate adaptive reactions. These reactions should not be accompanied by changes in functions that go beyond the limits of physical fluctuations. Otherwise, the normal functioning of the body may be disrupted, which will cause illness, and in some cases even death. Therefore, in the process of forming relationships with the environment, all animal and plant organisms have developed the ability not only to acquire new, hereditarily fixed qualities, but also to maintain the existing constancy of the chemical composition and functions of their body, i.e. homeostasis.

Despite the fact that animal and plant organisms differ in their chemical composition (concentration of substances), including the composition of fluids circulating in them (blood, lymph, tissue fluid), and in temperature, from the concentration and temperature regime of their environment, all these organisms retain their dynamic nonequilibrium state. The main expression of this is the ability of living objects to maintain their homeostasis by using adaptation mechanisms that differ in their degree of activity.

So, for some representatives of living beings, the means of maintaining homeostasis is a passive way of adapting to the environment. They have acquired the ability to switch to the maximum allowable low level of functional activity. However, such a way of adapting to changing conditions of existence is evolutionarily insufficiently reliable, since unfavorable conditions can remain unchanged for a longer time than the period during which the organism is able to maintain its vital activity. Therefore, circumstances may develop in such a way that the restoration of favorable living conditions will occur after the body has lost the ability to return from this state to active life.

Other representatives of living nature have formed active forms of adaptation, which make it possible to search for more suitable conditions of existence that ensure the preservation of homeostasis. Naturally, an active search is possible only if a living being is able to move in the surrounding space.

The third representatives of the living have predominantly developed mechanisms for active intervention in the outside world around them. This form of adaptation reached its highest perfection in man in the form of labor activity. Movement acts here not simply as a means of movement in space, but as the finest mechanism for the implementation of all forms of labor, creative, transforming activity. Thus, movement in all its diversity of expression is the most perfect way of adapting to the environment and actively influencing it. This is a way of active conversion.

The organism is characterized by the principle of integrity, which is characterized by the closest interconnection of all its organs and systems. A full-fledged movement that determines the adaptation of the body to new environmental conditions, primarily the muscles, the necessary food for its activity, oxygen, and the release of decay products. This requires the coordinated activity of the organs of circulation, respiration, digestion, excretion, and others regulated by the nervous system. Rationally used physical culture, sports contribute to the maintenance of homeostasis in a person, making up for the limitation of motor activity that has arisen as a result of the scientific and technical process.

The healing value of physical culture is well known. There are a huge number of studies showing the positive effect of physical exercises on the musculoskeletal system, central nervous system, circulatory functions, respiration, excretion, metabolism, thermoregulation and the activity of the internal secretion organs. As a result of physical training, the coordination of motor and vegetative functions by the nervous system is significantly improved; the functionality of many organs and systems of the body is increased, in some cases by several times. The functionality of individual human organs and systems is increased, which makes it much easier to cope with the increased requirements for the cardiovascular, respiratory and other body systems.

Great is the importance of physical exercises as a means of treatment, especially in diseases of the musculoskeletal system.

Changes in the mode of muscular activity can be reflected both in individual motor vegetative functions of the body, and in its overall stability (resistance) under the influence of adverse environmental factors.

Under the influence of strong irritations, tension arises in the body - stress. At the same time, a complex of changes develops, called the general adaptation syndrome. Of the three stages of stress, pathological changes in the body are observed in the first (anxiety reaction) and the third (exhaustion) stages. The second stage, which increases the body's resistance to both this factor and a number of others, is a physiological phenomenon.

The most important feature of the influence of muscle tension is that with a gradual increase in loads, the alarm reaction is weak or absent. In the body, after several training sessions, a state of increased resistance begins to develop as to specific ones, i.e. to the same factor, for example, muscle loads, and to non-specific ones, i.e. to a number of other adverse effects on the body. The third stage of stress - exhaustion - occurs only when the load is excessive for this organism. Thus, muscular work with a very large range of loads has only a positive effect on the body.

In particular, as was found in experiments on animal organisms and in observations of people, as a result of muscle activity, the body's resistance to many adverse effects that a person is exposed to in modern life, for example, to the effects of hypoxia, certain poisons, radioactive substances, increases nonspecifically. infections, overheating, cooling, etc.

During muscular activity, fatigue can occur, which is characterized by a complex of changes in the state of various body functions. The degree of manifestation of these changes, including the feeling of fatigue, is the greater, the more intense and longer the work was done.

Fatigue is a special condition that occurs as a result of work and manifests itself in the deterioration of motor and recovery functions and their coordination, decreased performance and the appearance of a feeling of fatigue. This state is temporary and disappears some time after the work is stopped, i.e. during rest.

External manifestations of muscle fatigue are varied. They depend on the nature of the physical exercises performed, the characteristics of the external environment and the personal individual characteristics of the organism. The external manifestations of fatigue include impaired coordination of movement, a drop in work productivity, shortness of breath, excessive sweating, and redness of the skin.

These external manifestations are due to both deterioration in the work of peripheral organs and a disorder in the coordination of their activity by the nervous system.

A change in the coordination of the functions of peripheral organs, which occurs some time after the start of work, occurs in some cases even before the decrease in the efficiency of the executive apparatus and is, as it were, a preventive measure that makes it possible to maintain high work efficiency for a longer time. In other cases, it occurs as a result of a disorder in the functions of the nervous system, which occurs with severe fatigue.

Deterioration of the functions of peripheral organs during work, resulting from inadequate nervous regulation, can manifest itself in various forms. First, the performance of various organs and organ systems (for example, minute blood volume, oxygen consumption) may decrease. Secondly, due to impaired coordination, a higher than necessary degree of mobilization of the functions of peripheral organs can be observed.

In order to maintain the efficiency of the peripheral executive apparatus, the nervous system can change the forms of coordination and their duration: replace the work of some muscle elements with others, reduce the depth of respiratory movements, etc.

Despite the fact that fatigue leads to a temporary decrease in performance, it has an important biological significance, being a signal of partial depletion of resources.

A decrease or cessation of the activity of skeletal muscles, the heart, endocrine glands and other organs always occurs in the presence of some residual supply of energy and other substances. This is due to the fact that both complete and partial, but a sharp decrease in the content of these substances can cause degeneration, and in some cases even death of certain cells of the body. Fatigue during work occurs even in the presence of significant reserves, leading to a decrease or cessation of activity. These reserves are partially used by a person in emergency cases.

When emotional states arise, the effects of the central nervous system on organs and tissues change significantly. With positive emotions, the influence through the sympathetic nerves is enhanced. This increases the secretion of catecholamines-adrenaline. An increase in the activity of the sympathetic-adrenaline system contributes to an increase in the degree of mobilization of energy resources in working organs and improves muscle activity. With negative emotions, a deterioration in a number of body functions and a decrease in efficiency can be observed.

Fatigue in the process of muscular or mental activity, which does not pass certain limits, is a physiological, not a pathological phenomenon, and is beneficial for the body.

Work to fatigue is an important factor in the growth of fitness, especially when it is associated with the development of endurance. The physiological meaning of this phenomenon lies in the fact that by training to the onset of fatigue, athletes adapt to increased loads. In cases where training exercises are stopped before the onset of fatigue, the development of fitness is suspended. The same happens if training sessions lead to a pronounced degree of fatigue. In this case, a state of overtraining may occur. As is clear from what has been said above, it is not fatigue “in general” that should be avoided in sports, but only its excessive development. At the same time, the limits of excessiveness are associated not only with the nature of the exercises performed, but also with their duration.

Muscular activity is usually accompanied by a temporary decrease in performance. After the end of work, in the recovery period, the internal environment of the body normalizes, energy reserves are restored, various functions come to a state of working readiness. All these processes not only ensure the restoration of the body's working capacity, but also contribute to its temporary increase.

Restorative processes partially proceed directly during muscular activity. An example of this is the oxidative reactions that ensure the resynthesis of energy-rich chemicals. However, at work, the processes of dissimilation prevail over the processes of assimilation. Only during prolonged muscular activity, characterized by a true steady state, a dynamic balance is established between the breakdown of chemicals and their resynthesis. The imbalance between these reactions is expressed during work the sharper, the greater its power and the less prepared a person is for it.

In the recovery period, assimilation processes predominate. This ensures the replenishment of energy reserves used up during operation. First, they are restored to their original level, then for some time they become higher than it and then decrease again.

In sports practice, various means are used that accelerate recovery processes.

One of the means that accelerates recovery after muscular work is active rest, i.e. switching to another activity.

Inhalation of humidified air accelerates the elimination of oxygen debt, in connection with which the intensity of restoration of working capacity increases.

Water procedures have a beneficial effect on the central nervous system. This is explained by the fact that afferent impulses from skin receptors cause new foci of excitation in certain parts of the brain, contributing to the establishment of optimal intercentral relationships.

The mechanism of action of massage is the same as that of water procedures. Afferent impulses from the skin and muscles change the functional state of the central nervous system. Vibration and hydromassage are especially effective.

Nutrition plays an important role in increasing the intensity of recovery processes. It should be high in calories and contain all the necessary organic and inorganic substances. Vitaminization of the body is extremely important in this case.

Recovery processes in a person are more intense in the presence of positive emotions. However, excessive arousal after work adversely affects recovery.

Physiological mechanisms and patterns of improvement

individual body systems under the influence of directed physical training

Insufficiency of muscle tension at work, at home and during movement adversely affects physiological functions. Some animals, placed in conditions of complete cessation of movements (akinesia) or their sharp limitation (hypokinesia), die after a few days or weeks, while others show pronounced negative changes in the morphological structure of tissues and functional properties of the body.

Hypokinesia is always accompanied by atrophy and degeneration of skeletal muscles. Muscle fibers become thinner, muscle weight decreases. After 30 days of complete cessation of activity, muscle strength decreases to 1/3 of the initial value, while the duration of a single contraction cycle increases by 1.5-2 times.

Significant changes in hypokinesia occur in the activity of the nervous system and sensory systems. These are disorders of motor functions (for example, an increase in the amplitude of oscillations of the center of gravity and impaired coordination when walking).

As a result of prolonged hypokinesia, pronounced changes occur in the circulatory system: the size of the heart decreases, the stroke and minute volume of blood decreases, the pulse quickens, etc.

With hypokinesia at rest, external respiration is characterized by a decrease in the volume of pulmonary ventilation, and the basal metabolism is reduced by 15-20%. There is also a decrease in the functions of the endocrine glands, in particular the adrenal glands.

During training, significant morphological and functional changes occur in all parts of the motor apparatus. The mass and volume of skeletal muscles increases. They increase the content of sarcoplasmic proteins and the contractile protein of myofibril - myosin.

In a trained body, carbohydrate reserves are increased, which is very important for improving performance. The vital capacity of the lungs (VC) and the maximum ventilation of the lungs increase. In trained people, the coefficient of use of oxygen from the inhaled air is increased.

Systematic training, especially long-term cyclic work, is accompanied by biochemical, morphological and functional changes in the heart and blood vessels.

Simultaneously with the hypertrophy of the walls of the heart, the volume of its cavities increases. For athletes, it averages about 1000 cm 3, for those who do not go in for sports, it is 30-40% less. The heart rate in trained, as a rule, is less than in non-athletes. In male athletes, the pulse is on average 55 beats / min., In women - 59, in non-athletes - 70. The reserve volume of blood also increases. It provides an increase in cardiac output during muscular work.

The total amount of blood in the body with the development of fitness increases slightly. The content of erythrocytes and hemoglobin in it increases.

Metabolism and energy

A distinctive feature of living organisms is energy expenditure and constant metabolism with their environment.

The nutrients that supply the body with energy and building materials are proteins, fats and carbohydrates. In addition, for the normal course of metabolism in the body, the intake of vitamins, water and mineral salts is necessary.

Metabolism in the body is a complex system of interconnected reactions of splitting (dissimilation) and synthesis (assimilation) of organic substances. During dissimilation reactions, potential chemical energy is released, which ensures the activity of all organs and the performance of the most important work. Fusion reactions require an influx of energy from outside for their implementation. All chemical reactions in the body, including food digestion, redox and other processes, are carried out with the participation of biological catalysts (enzymes).

Proteins are the main plastic material from which the cells and tissues of the body are built, for example, skeletal muscles contain about 20% of protein. When 1 g of protein is oxidized, 4.1 kcal is released.

Carbohydrates serve as the main source of energy in the body. When 1 g of carbohydrates are oxidized, 4.1 kcal is released. energy. Much less oxygen is required to oxidize carbohydrates than to oxidize fats. This especially increases the role of carbohydrates in muscle activity.

Fats have a higher energy value - 1 g of fat during oxidation releases 9.3 kcal. The total amount of fat in a person is on average 10-12% of body weight, with obesity it can reach 40-50%.

Energy consumption during physical work increases dramatically. For example, walking consumes 80-100% more energy compared to rest, while running - 400% or more.

Knowledge workers spend 3000-3500 kcal per day, while those engaged in heavy physical labor and athletes spend up to 7000 kcal or more per day.

Energy consumption during operation, which is calculated per unit of time or per unit of path, is directly proportional to its power. The total energy consumption depends not only on the power of the work, but also on its duration.

When a person performs mechanical work, the efficiency can reach 20-25%. The rest of the energy released in the body will turn into heat.

Muscular work is necessary for the normal functioning of the body. The amount of energy expended directly on muscle activity should be at least 1200-1300 kcal. per day.

Blood and circulation

Blood is a special liquid tissue of red color, slightly alkaline reaction, constantly moving through the blood vessels of a living organism. Blood consists of plasma and suspended formed elements in it - red blood cells (erythrocytes), white blood cells (leukocytes), platelets (platelets). 1 mm 3 of blood normally contains 4.5-5 million erythrocytes, 6-8 thousand leukocytes, 200-300 thousand platelets.

Red blood cells perform an important function - they transport oxygen from the lungs to the tissues of the body and carry carbon dioxide from the tissues to the lungs. They resemble the thinnest sponge, all the pores of which are filled with a special substance - hemoglobin, which easily captures and also easily releases oxygen and carbon dioxide.

Leukocytes perform a predominantly protective function, destroying proteins foreign to the body, including pathogenic microbes, and also play a significant role in metabolism, especially protein and fat.

Platelets play an important role in the complex process of blood clotting.

Plasma contains dissolved hormones, mineral salts, nutrients and other substances that it supplies tissues with, and also contains decay products removed from tissues. Blood plasma transports CO 2 to the lungs, one of the end products of oxidative reactions in body tissues.

The amount of blood is 7-8% of body weight. At rest, 40-50% of the blood is turned off from the circulation and is in the "blood depots": in the liver, spleen, in the vessels of the skin, muscles, and lungs. If necessary (for example, during muscular work), the reserve volume of blood is included in the circulation.

Blood in the body performs the following functions: trophic (nutritional) - carries O 2, nutrients; regulatory - transfers hormones, acts with its hydrostatic pressure on certain nerve endings; heat transfer - cools working muscles and other overheated tissues and heats insufficiently warm tissues; protective - fights against foreign bodies, clogs places of damage to the body.

All people are divided into 4 groups according to the biological properties of blood.

The I(0) group includes blood, the erythrocytes of which do not stick together in the plasma or serum of other blood groups. Group I blood can be transfused to all people.

Group II(A) includes blood whose erythrocytes stick together in plasma or blood serum of groups I and III. The blood of this group is compatible with the blood of groups II and IV.

Group III(B) includes blood that is incompatible with the blood of groups I and II.

Group IV (AB) includes blood that can only be transfused to people who have the same IV blood type.

Blood circulation is carried out through the blood vessels under the influence of the pressure difference in the arteries and veins. Arteries are blood vessels that carry blood away from the heart. Veins have thin and soft walls and valves that allow blood to flow only towards the heart.

Heart and circulatory system

The heart is the main organ of the circulatory system, which is a hollow muscular organ that performs rhythmic contractions, due to which the process of blood circulation in the body occurs.

The activity of the heart consists of three phases: atrial contraction, ventricular contraction and general relaxation of the heart. Heart weight 270-300 g, volume 500-750 cm3. In the process of regular physical education and sports, as a rule, there is an increase in the mass of the heart muscle and the size of the heart up to 350-500 g and 1000-1200 cm 3, respectively.

Indicators of heart performance are pulse rate, blood pressure, systolic blood volume, minute volume of blood.

Pulse - a wave of oscillations propagating along the elastic walls of the arteries as a result of the hydrodynamic impact of a portion of blood ejected into the aorta under high pressure during the contraction of the left ventricle.

Blood pressure is created by the force of contraction of the ventricles of the heart and the force of the walls of the vessels. The maximum pressure is observed in the aorta, the lowest in the veins when they flow into the right atrium. The pressure difference ensures a continuous flow of blood through the blood vessels.

Systolic blood volume is the amount of blood ejected from the left ventricle of the heart with each contraction.

Minute volume is the amount of blood ejected by the ventricle in 1 minute.

As a result of physical education and sports, performance indicators change for the better. A trained person, as a rule, at rest has a pulse and blood pressure below normal. At the same time, during intensive physical work, the pulse can reach 200-240 beats per minute, and the pressure rises faster, stays high longer, maintaining high performance, and returns to normal faster.

The systolic blood volume reaches 230 ml in athletes, and 130 ml in untrained people. The minute volume for athletes is 35-42 liters, for untrained people it is 22-25 liters.

The cardiovascular system consists of large and small circles of blood circulation. The left half of the heart serves a large circle of blood circulation, the right - a small one. A large circle, starting from the left ventricle of the heart, passes through the tissues of all organs and returns to the right atrium. From the right atrium, the blood passes into the right ventricle, and from there the pulmonary circulation begins, which passes through the lungs, where venous blood, giving off carbon dioxide and being saturated with O 2, turns into arterial blood and goes to the left atrium. From the left atrium, blood passes into the left ventricle and from there again into the systemic circulation.

Respiratory system

The human respiratory apparatus consists of lungs located in the chest; airways - nasal cavity, nasopharynx, trachea, bronchi - and respiratory muscles.

Atmospheric air enters the trachea through the nose and mouth, passes into the right and left bronchi, which branch out in a tree-like manner. From the small bronchi, air through the bronchioles fills the pulmonary vesicles - alveoli, the walls of which consist of epithelial cells and supporting connective tissue. Through the alveolar membrane, gases are exchanged between the alveolar air and blood flowing through the capillaries that braid the pulmonary vesicles.

Renewal of air in the alveoli occurs due to changes in the volume of the chest as a result of contraction of the intercostal muscles and diaphragm. The hermetically sealed pleural cavity, more precisely the pleural fissure, is important. It is formed by the visceral (covering the lung) and parietal (lining the inside of the chest) layers of the pleura and is filled with a small amount of fluid.

The total amount of air that the lungs can hold at maximum inhalation is called the total lung capacity and consists of four components.

Tidal volume is the amount of air that passes through the lungs in one breath. At rest, it is equal to 350-800 ml, during muscular work it can reach 1-2 liters.

The reserve volume of air is the air that can be additionally inhaled after a normal inspiration.

The reserve volume of air is the volume of air that can be additionally exhaled after a normal exhalation.

Residual is the volume of air that remains in the lungs after maximum exhalation.

Vital capacity (VC) - the maximum amount of air that a person can exhale after a maximum breath. The value of VC depends on height, weight, physical development and many other factors and varies widely from 1500 to 7500 ml. The average values ​​of VC in men are 3800-4200 ml., in women 3000-3500 ml.

A quantitative indicator of pulmonary ventilation is the respiratory minute volume (MOD). It is equal to the product of the tidal volume times the number of breaths per minute. During muscular work, pulmonary ventilation can increase compared to the rest level by 25-30 times.

The amount of O 2 required for oxidative processes that provide this or that work is called oxygen demand. Distinguish between total and minute oxygen demand.

The maximum consumption of O 2 (MPC) is the largest amount of O 2 that the body can absorb during extremely difficult work for it and is directly dependent on the degree of physical fitness.

In non-athletic people, the IPC limit is at the level of 2-3.5 l / min. In athletes, the IPC can reach 4 l / min and more in women; in men - 6 l / min or more.

Oxygen debt is the amount of oxygen necessary for the oxidation of metabolic products accumulated during physical work. Oxygen debt occurs when a person's oxygen demand is above the oxygen consumption ceiling. In untrained people, oxygen debt is within 10 liters, in trained people it can reach 20 liters or more.

Musculoskeletal system

The musculoskeletal system consists of bones, ligaments, muscles, muscle tendons. There are about 200 bones.

Sports activities increase the strength of the tissue, contribute to a stronger attachment to the bones of muscle tendons, strengthen the spine, contribute to the expansion of the chest and the development of good posture.

The main function of the joints is the implementation of movements. At the same time, they act as a kind of brakes that dampen the inertia of movement. When playing sports, the joints develop, the elasticity of their ligaments and muscle tendons increases, and their flexibility increases.

The muscular system ensures the movement of a person, the vertical position of the body, the function of internal organs in a certain position, respiratory movements, increased blood and lymph circulation, thermoregulation of the body along with other systems. A person has more than 600 muscles. They make up 35-40% of body weight in men (50% or more in athletes), slightly less in women.

The muscle consists of bundles of muscle fibers running parallel to each other. Muscle contraction is caused by an impulse coming from the CNS. The muscle is always in a state of some contraction called tone. Muscles are richly supplied with blood vessels, as a result of which energy metabolism takes place in them. In muscles, an actively contracting part is distinguished - the abdomen and a passive part, with which it is attached to the bones - tendons. Muscles come in a variety of shapes - short, wide, long, thick or thin. The shape of a muscle depends on the function it performs.

Digestive and excretory organs

The digestive organs include the mouth, stomach, duodenum, small and large intestines. In the oral cavity and stomach, physical and chemical processing of food takes place, in other departments - only chemical. In the small intestines, the digestion of food and the absorption of nutrients into the blood are mainly completed. Additional digestion occurs in the large intestine.

The excretory organs include the gastrointestinal tract, lungs, kidneys, sweat, sebaceous, lacrimal and some other glands.

The gastrointestinal tract removes the remnants of undigested food, mucus, etc. from the body through the rectum. Gaseous metabolic products are removed through the lungs. The main function of releasing the body from the end products of metabolism is carried out by the kidneys, lungs and sweat glands. The kidneys carry out several functions: they maintain a normal concentration of water, salts and a number of other substances; regulate acid-base balance and osmotic pressure in body tissues; remove from the body the end products of protein metabolism and foreign substances.

Through the sweat glands at rest, 20-40 ml of sweat is released. But under loads, for example, on a march at a speed of 5 km / h, with a load of 10 kg, people sweated in an amount of 1000 to 1700 ml per hour.

Sensor systems

Depending on the nature of the stimuli, it is possible to conditionally divide all sensory systems into several groups that respond to the following types of stimuli:

mechanical (tactile, pain, motor, vestibular analyzers, etc.);

chemical (taste, olfactory analyzers);

light (visual analyzer);

sound (auditory analyzer);

temperature.

According to the environment from which stimuli are perceived, sensory systems are divided into two main groups:

external (visual, auditory, olfactory, gustatory and tactile (tactile));

internal - chemical (responding to a change in the chemical composition of blood and tissue), barosthetic (responding to a change in pressure, for example, in blood vessels).

As a result of systematic physical training, the functions of many analyzers improve. Thus, in weightlifters and boxers, a high sensitivity of the motor analyzer is observed during movements in the elbow and shoulder joints, in skiers, jumpers and slalomists - during movements in the ankle joints. Improving the functions of the visual apparatus (increasing the field of view) is noted among representatives of sports games. The functions of the vestibular sensory system are improved as a result of training in gymnastic exercises, swimming, etc.

Endocrine glands

The endocrine glands include the pituitary gland, thyroid gland, pancreas, gonads, adrenal glands.

Together, the endocrine glands form the endocrine system. Its center is one of the parts of the brain called the hypothalamus. Its main feature is that it simultaneously refers to both the endocrine and nervous systems. With the help of special hormones, the hypothalamus regulates the activity of the pituitary gland, and the latter, with the help of its hormones, regulates the activity of other glands.

The endocrine system works normally only if it is known on each of its “floors” what is happening on other “floors”. Such information is provided by direct and feedback.

Nervous system

The nervous system is divided into central and peripheral. The CNS includes the spinal cord and brain; to the peripheral - nerve fibers, nerves connecting nerve cells to each other, as well as nerve cells in all human organs. The nervous system is conditionally divided into somatic and autonomic. Somatic provides regulation of the motor apparatus, vegetative provides and regulates the course of metabolic processes and the work of internal organs and systems.

There are afferent (centripetal, sensory) nerves, the excitation through which from different parts of our body goes to the central nervous system. Another group of nerves is efferent (centrifugal, motor). Through them, excitation goes from the central nervous system to the working organs.

Humoral and nervous regulation of body activity

The humoral mechanism is carried out at the expense of chemicals that are in the fluids circulating in the body (blood, lymph, tissue fluid). Chemical regulators of functions can be various substances, but hormones are the most important. They influence the course of metabolism, the formation of organs and tissues, they can "start" the activity of various organs and, finally, coordinate the intensity of the functions of the body or its organs.

A distinctive feature of humoral regulation is that the chemical regulator, entering the bloodstream, enters all organs and tissues, regardless of whether it participates in the regulation of functions or not. The rate of distribution of the hormone corresponds to the rate of blood flow.

Between hormones, the principle of self-regulation is manifested. So, if the hormone of the pancreas (insulin) helps to reduce blood sugar levels, then the hormone of the adrenal medulla (adrenaline) - to increase it.

The nervous mechanism of regulation is evolutionarily younger. Nerve impulses propagate along the nerve pathways at a fairly high speed (from 0.5 to 80-120 m / s) and go along certain nerve fibers to strictly defined organs.

The main nervous mechanism for the regulation of functions is a reflex - a response of the body, which is realized along a reflex arc. It includes 1) perceiving receptors; 2) afferent nerve fibers that carry excitation to the central nervous system; 3) transmission neurons and synapses that conduct excitation to effector neurons; 4) efferent nerve fibers that transmit excitation to the executive organ. There are 2 types of reflectors: unconditioned - congenital and conditional - acquired during life.

Nervous and humoral regulation of functions are interconnected and form a single neurohumoral regulation.

Features of the functioning of the central nervous

systems (CNS)

The activity of the central nervous system is characterized by a certain orderliness and consistency of reflex reactions, i.e. their coordination. The interaction of two nervous processes - excitation and inhibition - underlying all the complex regulatory functions of the body, the regularity of their simultaneous flow in various nerve centers, as well as the successive change in time determine the accuracy and timeliness of the body's responses to external and internal influences.

The spread of the excitation process to other nerve centers is called irradiation. Due to the irradiation of excitation between different nerve centers, new functional connections arise - conditioned reflexes. On this basis, it is possible, for example, to form new motor skills.

Inhibition in the CNS. Some nerve centers can significantly change the reflex activity in other centers, in particular, the overlying nerve centers can inhibit the activity of the underlying ones.

The activity of the nerve centers is unstable and the predominance of the activity of some of them over the activity of others causes noticeable changes in the processes of coordination of reflex reactions. The term dominant was used to denote the dominant organ of excitation in the central nervous system, which determines the current activity of the organism.

The main features of the dominant: 1) increased excitability of the nerve centers; 2) persistence of excitation over time; 3) the ability to sum up extraneous stimuli; 4) inertia of the dominant.

The dominant ensures the flow of the main functions.

For example, a rhythmic walking reflex and a single, continuous flexion reflex during painful stimulation are antagonistic. However, an athlete who is suddenly injured may continue to run to the finish line, i.e. a rhythmic reflex is carried out and pain stimuli are suppressed, which, entering the motor neurons of the flexor muscles, prevent alternate flexion and extension of the leg.

The reflex nature of motor activity

Considering various human motor acts, one can single out elementary motor reflexes, more complex rhythmic reflexes, and, finally, especially complex forms of motor activity that ensure human behavior.

Elementary motor reflexes are carried out by the spinal cord. Simple unconditioned motor reflexes of the spinal cord include 1) stretch reflexes; 2) flexion reflexes to irritation of skin receptors; 3) repulsion reflexes.

Rhythmic reflexes are especially pronounced when performing cyclic movements, for example, the stepping reflex, which lies in the process of walking, running and other locomotions. The mechanisms of stepping movements are already laid down at the level of the spinal cord. The cerebellum also participates in the implementation of the stepping reflex. The removal of one of its hemispheres in animals leads to a distortion of movements. The highest regulator of reflexes is the cerebral cortex, especially its premotor area. Thanks to the cortex, rhythmic movements (for example, the simple act of walking) acquire a certain semantic meaning and are included as an integral element in complex behaviors.

In holistic behavior, simple reflexes, combined, cause complex motor actions. The social conditions of a person's life greatly complicate his motor activity, leading to the emergence of specially human forms of movements: domestic, industrial, sports. Simple and complex rhythmic reflexes underlie human cyclic activity: walking, running, swimming, rowing, skiing, cycling, etc.

Voluntary human movements are the result of the combined activity of the most diverse departments of the central nervous system. A multi-storey and multi-link functional system, consisting of many hundreds, thousands and millions of neurons, is involved in the regulation of such actions. The operation of this system is reduced to determining the optimal ways to solve motor problems, for example, the right moment to start a movement, the most suitable for its structure, etc.

Motor skill education

A motor skill is a form of motor actions developed by the mechanism of a conditioned reflex as a result of appropriate exercises.

The process of forming a skill is conditionally divided into stages, the number of which is different for different authors. Physiologists speak of three stages, educators and psychologists of three to six. Let's look at three stages.

The formation of a motor skill sequentially goes through 3 phases: generalization, concentration, automation.

The generalization phase is characterized by the expansion of the excitatory process. This expansion occurs due to the involvement of extra muscle groups in the work. Movements are constrained, angular, poorly coordinated and inaccurate, uneconomical.

Concentration phase - excessively diffuse excitation, due to differentiated inhibition, is concentrated in the necessary areas of the brain. Excessive tension of movements disappears; they become stingy, precise, economical, free, their execution becomes much more stable.

In the automation phase, the skill is so refined and consolidated that the execution of the necessary movements becomes, as it were, automatic and does not require the activity of consciousness control. This skill is characterized by high stability in the performance of all its constituent movements. Automation of skills makes it possible to perform several motor actions simultaneously. For example, the juggler maintains balance while standing on the saddle of a galloping horse, balances a pyramid of various objects placed on his forehead and, in addition, juggles with several maces.

Reflex mechanisms for improving motor

activities

In the process of training, various organs and systems are improved, their interaction is being established. The essence of the exercise is physiological, biochemical and morphological changes that occur under the influence of repeatedly repeated muscular work and reflect the unity of consumption and restoration of functional and structural resources in the human body.

During training, the central nervous system improves, the interaction of excitation processes improves in it. These processes can be concentrated in all muscle structures of the central nervous system and function clearly in certain periods. At the same time, the interaction of nerve centers that regulate the contraction and relaxation of various muscle groups becomes more and more clear, providing dynamics in time and space of muscle contractions.

Training leads to an increase in the ability of the senses to distinguish finer characteristics of the dynamics of muscle contractions. At the same time, a person gains the ability to better assimilate new movements and restructure existing ones. In the process of training, a person gets the opportunity to more widely and deeply evaluate the actions performed. This indicates an improvement in the relationship between consciousness and movement (the second and first signal systems).

Motor function and increasing the level of adaptation and resistance of the human body to various environmental conditions

In physiological studies of adaptation, the problem of daily and seasonal dynamics of physiological functions is distinguished, which changes under the influence of natural environmental factors. The motor function developed in the specific conditions of life on earth, which predetermined its place in the formation and preservation of the vital activity of the organism as a whole. Working and living conditions are of great importance, i.e. the whole complex of social factors. The influence of gravitational forces, inertia, time and space on the development of a person's motor function is reflected in the formation of features in the development of the functions of various muscle groups.

The motor function ensures the preservation and deepening of the body's connections with the environment, both by improving the mechanisms that provide control of movements that are complex in coordination, and as a result of strength, speed, and endurance.

Physical training has an equilateral effect on mental functions, ensuring their activity and stability. The basis of stability of the psyche is laid at an early age. At the same time, the significance of the motor function for the development of speech and thinking is especially clearly revealed in the early stages of ontogenesis (individual development).

Mental performance deteriorates to a lesser extent under the influence of adverse factors (isolation, hypodynamia, unfavorable microclimate, etc.), if physical exercises are applied appropriately under these conditions.

The value of the body's physical readiness especially increases when it is necessary to adapt to rapidly changing environmental conditions. For example, the poor physical preparation of some cadets makes it difficult to develop professional flying skills among pilots. They tire quickly in flight and cannot successfully train. In other cases, the cause is insufficient resistance to the effects of accelerations (to motion sickness and overloads). Physical exercises not only contribute to adaptation to various working conditions, but also provide active mastery of many professions.

The physical training of cosmonauts is aimed at increasing the resistance of the organism to the action of acceleration, developing the skills of free control of the body in space, and performing subtle movements in coordination. These are gymnastic exercises, diving, swimming, exercises on special equipment, etc. Training is carried out in conditions that imitate the features of space flight - flying on airplanes in zero gravity, parachuting and staying in an isolated chamber.

Active movements stimulate the development of the body's vegetative environment. They reduce high blood pressure and, on the contrary, lead to normal low blood pressure, normalize cholesterol levels in the blood, and have a positive effect on salt metabolism.

Motor function is the main function of the human body. The one who constantly improves it, improves his body.

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Introduction 2

1. The body as a single self-developing and self-regulating biological system 4

2. Functional systems of the body 6

3. The external environment and its impact on the body and human life 10

Conclusion 14

List of used literature 15

Introduction

Scientific and technical, social progress brings not only good. It leads to environmental pollution, increases the requirements for stress resistance, necessitates the assimilation of a large information flow, reduces the amount of human motor activity, which together leads to poor health. The only weapon of a person in protecting health in the created conditions is physical culture.

Physical culture is a part of the general culture, a type of activity aimed at understanding and transforming the physical nature of a person. Physical culture as an integral part of general culture is an obligatory academic discipline in higher educational institutions.

According to Timushkin A.V., physical culture acts as a necessary part of the lifestyle of students, because it is an integral part of human culture, the area of ​​meeting vital needs in motor activity, solves the problem of physical perfection, solves the problems of rational use of free time. Daily academic work, test and examination sessions (2 times a year), educational practices - all this requires students not only diligence, but also good health, good psychophysical fitness.

P.F. Lesgaft, speaking about the importance of physical culture, emphasized: “The discrepancy between a weak body and developed mental activity will invariably have a negative impact on a person. in practice" [Lesgaft P.F. Selected pedagogical works. - M., 1988].

The expression "physical training" corresponds to the everyday consciousness and language of people. It should be understood as an activity for the development and improvement of a person's inherent in him, his natural abilities, qualities, including morphofunctional and mental ones.

Biomedical and pedagogical sciences deal with man as a being not only biological, but also social. Sociality is the specific essence of a person, which does not abolish his biological substance, because the biological principle of a person is a necessary condition for the formation and manifestation of a social lifestyle. Meanwhile, they make history, change the living and inanimate world, create and destroy, set world and Olympic records not by organisms, but by people, human personalities. Thus, the socio-biological foundations of physical culture are the principles of the interaction of social and biological patterns in the process of mastering the values ​​of physical culture by a person.

Naturally - the scientific foundations of physical culture - a complex of biomedical sciences (anatomy, physiology, biology, biochemistry, hygiene, etc.).

Anatomy and physiology are the most important biological sciences about the structure and functions of the human body. Man obeys the biological laws inherent in all living beings. However, it differs from the representatives of the animal world not only in its structure, but also in its developed thinking, intellect, speech, features of social and living conditions of life and social relationships.

Labor and the influence of the social environment in the process of human development have influenced the biological characteristics of the organism of modern man and his environment. The study of human organs and interfunctional systems is based on the principle of integrity and unity of the organism with the external natural and social environment.

The relevance of this topic lies in the fact that without knowledge about the structure of the human body, about the patterns of functioning of individual organs and systems of the body, about the features of the flow of complex processes of its life, the influence of social conditions, it is impossible to organize the process of forming a healthy lifestyle and physical training of the population, including and student youth.

The purpose of this work is to study the socio-biological foundations of physical culture.

Based on the specified purpose of the work, the tasks are:

1) To study the body as a single biological system;

2) Consider the functional systems of the body;

3) To study the environmental factors that affect the student's body.

1. The organism as a single self-developing and self-regulating biological system

An organism is a complex single self-regulating and self-developing biological system, the functional activity of which is determined by the interaction of mental, motor and vegetative reactions to environmental influences.

The development of the organism is carried out in all periods of his life - from the moment of conception to the end of life. This development is called individual, or development in ontogeny. In this case, two periods are distinguished: intrauterine (from the moment of conception to birth) and extrauterine (after birth).

Each born person inherits from his parents congenital, genetically determined traits and characteristics that largely determine individual development in the process of his later life. Once after birth, figuratively speaking, in an autonomous mode, the child grows rapidly, the mass, length and surface area of ​​his body increase. Human growth continues until about 20 years of age. Moreover, in girls, the greatest intensity of growth is observed in the period from 10 to 13, and in boys from 12 to 16 years. An increase in body weight occurs almost in parallel with an increase in its length and stabilizes by the age of 20–25. It should be noted that over the past 100 - 150 years in a number of countries there has been an early morphofunctional development of the body in children and adolescents. This phenomenon is called acceleration (lat. acce1era - acceleration), it is associated not only with the acceleration of growth and development of the body in general, but also with the earlier onset of puberty, accelerated development of sensory (lat. boar - feeling), motor coordination and mental functions . Therefore, the boundaries between age periods are rather arbitrary and this is due to significant individual differences, in which the "physiological" age and "passport" age do not always coincide. As a rule, adolescence (16 - 21 years) is associated with a period of maturation, when all organs, their systems and apparatuses reach their morphological and functional maturity.

Student age, according to Timushkin A.V., can be called the final stage of the progressive age-related development of the psychophysiological and motor capabilities of the body. Young people during this period have great opportunities for intense educational work, social and political activities. That is why physical culture and sports become for them the most important means of health promotion, a natural, biological basis for the formation of personality, effective educational work, mastery of science and profession.

A healthy lifestyle, active motor activity in the process of life significantly slow down the aging process. The vital activity of the organism is based on the process of automatic maintenance of vital factors at the required level, any deviation from which leads to the immediate mobilization of mechanisms that restore this level (homeostasis).

According to Yu.L. Oxygen, homeostasis is a set of reactions that ensure the maintenance or restoration of a relatively dynamic constancy of the internal environment and some physiological functions of the human body (blood circulation, metabolism, thermoregulation, etc.). This process, according to the author, is provided by a complex system of coordinated adaptive mechanisms aimed at eliminating or limiting factors affecting the body both from the external and from the internal environment. These mechanisms make it possible to maintain the constancy of the composition, physicochemical and biological properties of the internal environment, despite changes in the external world and physiological changes that occur during the life of the organism. In the normal state, fluctuations in physiological and biochemical constants occur within narrow homeostatic boundaries, and the cells of the body live in a relatively constant environment, as they are washed by blood, lymph and tissue fluid. The constancy of the physico-chemical composition is maintained due to the self-regulation of metabolism, blood circulation, digestion, respiration, excretion and other physiological processes.

Thus, the human body is a complex biological system consisting of a huge number of cells and tissues, each of which performs its own functions inherent only to it in the overall structural and functional system of the body. In the process of vital activity, tissues are supplied with nutrients and the necessary amount of oxygen in order to carry out the vital processes of energy generation, removal of decay products, ensuring various biochemical reactions of vital activity, etc. These processes occur due to regulatory mechanisms that operate through the nervous, circulatory, respiratory, endocrine and other systems of the body.

1. Functional systems of the body

The totality of organs that perform a common function for them is called the organ system (digestive, respiratory, cardiovascular, sexual, urinary, etc.) and the organ apparatus (musculoskeletal, endocrine, vestibular, etc.).

The human musculoskeletal system consists of bones, ligaments, muscles, and muscle tendons. Its main functions are to support and move the body and its parts in space. The basis is the skeleton - a complex of bones, different in shape and size. A person has more than 200 bones (85 paired and 36 unpaired). The human skeleton consists of the spine, skull, chest, limb belts and the skeleton of free limbs. All bones of the skeleton are connected through joints, ligaments and tendons. Joints are movable joints, the area of ​​​​contact of the bones in which is covered with an articular bag of dense connective tissue, fused with the periosteum of the articulating bones.

The muscular system is represented by two types of muscles: smooth (involuntary) and striated (voluntary). Smooth muscles are located in the walls of blood vessels and some internal organs. They constrict or dilate blood vessels, move food through the gastrointestinal tract, and contract the walls of the bladder. The striated muscles are all skeletal muscles that provide a variety of body movements.

Skeletal muscles are part of the structure of the musculoskeletal system, are attached to the bones of the skeleton and, when contracted, set in motion individual links of the skeleton, levers. They are involved in maintaining the position of the body and its parts in space, provide movement when walking, running, chewing, swallowing, breathing, etc., while generating heat. Skeletal muscles have the ability to be excited under the influence of nerve impulses. Excitation is carried out to contractile structures (myofibrils), which, while contracting, perform a certain motor act - movement or tension.

In the process of muscle contraction, potential chemical energy is converted into potential mechanical energy of tension and kinetic energy of movement. Chemical transformations in the muscle proceed both in the presence of oxygen (under aerobic conditions) and in its absence (under anaerobic conditions). The primary source of energy for muscle contraction is the breakdown of ATP. Each gram molecule of ATP releases 10,000 calories. ATP stores in the muscle are negligible and continuous ATP resynthesis is required to keep them active. It occurs due to the energy obtained from the breakdown of creatine phosphate (CrF) into creatine (Cr) and phosphoric acid (anaerobic phase). In this case, 46 kJ are released for each mole of CRF.

Blood is a liquid tissue that circulates in the circulatory system and ensures the vital activity of cells and tissues of the body as an organ and physiological system. It consists of plasma (55-60%) and formed elements suspended in it: erythrocytes, leukocytes, platelets and other substances (40-45%); has a slightly alkaline reaction (7.36 pH).

Erythrocytes - red blood cells are filled with a special protein - hemoglobin, which is able to form a compound with oxygen (oxyhemoglobin) and transport it from the lungs to the tissues, and from the tissues to transfer carbon dioxide to the lungs, thus carrying out the respiratory function. Leukocytes - white blood cells, perform a protective function, destroying foreign bodies and pathogenic microbes (phagocytosis). 1 ml of blood contains 6-8 thousand leukocytes. Platelets (and they are contained in 1 ml from 100 to 300 thousand) play an important role in the complex process of blood coagulation. Hormones, mineral salts, nutrients and other substances with which it supplies tissues are dissolved in blood plasma, and also contains decay products removed from tissues.

The cardiovascular system consists of the heart and blood vessels. The heart - the main organ of the circulatory system - is a hollow muscular organ that performs rhythmic contractions, due to which the process of blood circulation in the body occurs. Pulse - a wave of oscillations propagating along the elastic walls of the arteries as a result of the hydrodynamic impact of a portion of blood ejected into the aorta under high pressure during the contraction of the left ventricle. The pulse rate corresponds to the heart rate. At rest, the pulse of a healthy person is 60-70 beats / min. Blood pressure is created by the force of contraction of the ventricles of the heart and the elasticity of the walls of blood vessels. It is measured in the brachial artery. Distinguish between the maximum (or systolic) pressure, which is created during the contraction of the left ventricle (systole), and the minimum (or diastolic) pressure, which is noted during the relaxation of the left ventricle (diastole). Normally, a healthy person aged 18-40 at rest has a blood pressure of 120/70 mm Hg. (120 mm systolic pressure, 70 mm diastolic).

The respiratory system includes the nasal cavity, larynx, trachea, bronchi and lungs. In the process of breathing from atmospheric air through the alveoli of the lungs, oxygen constantly enters the body, and carbon dioxide is released from the body. The trachea in its lower part is divided into two bronchi, each of which, entering the lungs, branches in a tree-like manner. The final smallest branches of the bronchi (bronchioles) pass into closed alveolar passages, in the walls of which there are a large number of spherical formations - pulmonary vesicles (alveoli). Each alveolus is surrounded by a dense network of capillaries. The total surface of all pulmonary vesicles is very large, it is 50 times greater than the surface of human skin and is more than 100 m 2. The process of respiration is a whole complex of physiological and biochemical processes, the implementation of which involves not only the respiratory apparatus, but also the circulatory system.

Description of work

The purpose of this work is to study the socio-biological foundations of physical culture.
Based on the specified purpose of the work, the tasks are:
1) To study the body as a single biological system;
2) Consider the functional systems of the body;
3) To study the environmental factors that affect the student's body.
 

The socio-biological foundations of physical culture are the principles of the interaction of social and biological patterns in the process of mastering the values ​​of physical culture by a person.

Without knowledge about the structure of the human body, about the patterns of functioning of individual organs and systems of the body, about the features of the flow of complex processes of its life, it is impossible to organize the process of forming a healthy lifestyle and physical training of the population, including young students. The achievement of biomedical sciences underlies the pedagogical principles and methods of the educational and training process, the theory and methodology of physical education and sports training.

Anatomical and morphological features and basic physiological functions of the body

The body is a well-coordinated single self-regulating and self-developing biological system, the functional activity of which is due to the interaction of mental, motor and vegetative reactions to environmental influences, which can be both beneficial and detrimental to health. A distinctive ability of a person is a conscious and active influence on external natural and social conditions that determine the state of people's health, their performance, life expectancy and fertility (reproductivity).

The body is made up of organs and tissues. Organs are built from tissues, tissues are made up of cells and intercellular substance.

A cell is an elementary, universal unit of living matter, having an ordered structure, metabolism and energy, capable of growth, regeneration, reproduction, transmission of genetic information and adaptation to environmental conditions. The whole variety of cells has common biological features of the structure - the nucleus and cytoplasm, which are enclosed in a cell membrane. There are over 100 trillion cells in the human body.

The intercellular substance is a product of the vital activity of cells, it consists of the main substance and the connective tissue fibers located in it.

Tissue - a collection of cells and intercellular substance that have a common origin, the same structure and functions.

There are four types of fabric:

1) epithelial - performs integumentary, protective, absorption, excretory and secretory functions;

2) connective - loose, dense, cartilaginous, bone tissue and blood;

3) muscular - striated, smooth and cardiac;

4) nervous.

An organ is a part of a whole organism, which is a complex of tissues that has developed in the process of evolutionary development and performs certain specific functions.

Functional systems of the body

The functional systems of the body include the skeletal and muscular systems.

Skeletal system

Skeleton (from the Greek. sceleton - dried up, dried) - a complex of bones, different in shape and size. A person has more than 200 bones: 85 paired and 36 unpaired.

The composition of the bone includes inorganic (phosphorus and calcium) and organic (bone cells and collagen fibers) substances. Elasticity, elasticity of bones depends on the presence of organic substances in them, and hardness is provided by mineral salts.

Muscular system

The movements of the human body are provided by the musculoskeletal system, which consists of a passive part (bones, ligaments, joints and fascia) and an active part - muscles, formed mainly by muscle tissue. Both of these parts are interconnected in development, anatomically and functionally.

Distinguish between smooth and striated muscle tissue. Muscular membranes of the walls of internal organs, blood and lymphatic vessels are formed from smooth muscle tissue. Contractions of smooth muscles are not subject to the will, therefore they are called involuntary.

Striated muscle tissue forms muscles that are mainly attached to various parts of the skeleton, which is why they are also called skeletal. The contractions of these muscles are called arbitrary, because. they are subject to will.

Muscles that perform the same movement are called synergists, and those that perform opposite movements are called antagonists. The action of each muscle can occur only with the simultaneous relaxation of the antagonist muscle, such coordination is called muscle coordination. Complex movements (such as walking) involve many muscle groups.

The striated muscles are subdivided into the muscles of the trunk, head and neck, upper and lower extremities.

The cardiac muscle differs in structure and function from striated and smooth. It has a property that is absent in other muscles - the automaticity of contractions, which has a certain rhythm and strength. The heart muscle does not stop its rhythmic work throughout life. The nervous system regulates the frequency, strength, rhythm of heart contractions.

Physiological systems of the body

The physiological systems of the body are the blood, the cardiovascular system, the respiratory system, the digestive and excretory system, the excretory system, the nervous system, receptors and analyzers, the endocrine system.

Blood is a liquid tissue that circulates in the circulatory system and ensures the vital activity of the cells and tissues of the body. It consists of plasma (55-60%) and erythrocytes, leukocytes, platelets and other substances suspended in it.

Erythrocytes are red blood cells filled with a protein - hemoglobin, which combines with oxygen and transports it from the lungs to the tissues, and from the tissues transports carbon dioxide to the lungs. 1 ml of human blood normally contains 4.5-5.0 million erythrocytes. In people who move, this number can increase to 6 million / ml or more.

Leukocytes are white blood cells that perform a protective function in the destruction of foreign bodies and pathogenic microbes. 1 ml contains from 6 to 8 thousand leukocytes.

Platelets contribute to blood coagulation (in 1 ml from 100 to 300 thousand). In the blood plasma there are also antibodies that create the body's immunity to toxic substances of infectious and any other origin, microorganisms and viruses.

When blood moves through the capillaries penetrating all tissues, a part of the blood plasma constantly leaks through their walls into the interstitial space, which forms an interstitial fluid that surrounds all cells of the body. From this fluid, cells absorb nutrients and oxygen and release carbon dioxide into it, as well as other decay products formed during metabolism. Thus, the blood continuously gives the nutrients used by the cells into the interstitial fluid and absorbs the substances used by them.

The total amount of blood is 7-8% of a person's body weight. At rest, 40-50% of the blood is turned off from the circulation and is in the "blood depots": in the liver, spleen, skin vessels, and lung muscles. The release of blood from the "depot" and its redistribution throughout the body is regulated by the central nervous system.

From the foregoing, the following functions of blood can be listed: transport, trophic, regulatory, protective.

Cardiovascular system (CVS)

CCC is one of the most important integrating systems of the body. It not only ensures the unity of the internal environment, but also allows the body to adapt to changes.

CCC is the heart and blood vessels.

The heart is a four-chambered muscular organ. His work consists of contractions - systole and relaxation - diastole. In addition, there is a pause.

The rhythm of the heart is of great importance in the life of the body. In a healthy person, the main indicators of the functioning of the cardiovascular system are heart rate (HR) and blood pressure (BP).

Pulse - a wave of oscillations propagating along the walls of the arteries as a result of the hydrodynamic impact of a portion of blood ejected into the aorta under high pressure during the contraction of the left ventricle. At rest, in a healthy person, the heart rate is 60-70 beats / min. Increase - tachycardia, decrease - bradycardia.

Blood pressure - is created by the force of contraction of the ventricles of the heart and the elasticity of the walls of blood vessels. Distinguish between systolic (max) pressure, which is created during the contraction of the left ventricle and diastolic (min), is noted during the relaxation of the left ventricle. The pressure is maintained by the elasticity of the walls of the distended aorta and large arteries. Normal - 120/70 mm Hg. Art., 110/60 mm Hg. Art. An increase is hypertension, a decrease is hypotension.

CCC consists of large and small circles of blood circulation. The left half of the heart serves a large circle, the right - a small one.

Physical activity of a person, physical exercises, sports have a significant impact on the state of the cardiovascular system. Perhaps no organ needs so much training and does not lend itself to it so easily as the heart. Working with a heavy load when performing sports exercises, the heart inevitably trains. The limits of its capabilities are being expanded, it is adapting to pumping much more blood than the heart of an untrained person can do. In the process of regular exercise and sports, as a rule, there is an increase in the mass of the heart muscle and the size of the heart. So, the mass of the heart of an untrained person averages about 300 g, for a trained person - 500 g.

Physical work contributes to the expansion of blood vessels, reducing the tone of their walls; mental work, as well as neuro-emotional stress, leads to vasoconstriction, an increase in the tone of their walls, and even spasms. This reaction is especially characteristic of the vessels of the heart and brain. Long-term intense mental work, not balanced with active movement and physical activity, frequent neuro-emotional stress can lead to a deterioration in the nutrition of these most important organs, to a persistent increase in blood pressure, which, as a rule, is the main symptom of hypertension. Evidence of the disease is also a decrease in blood pressure at rest (sweating), which may be the result of a weakening of the activity of the heart muscle. As a result of special physical exercises and sports, blood pressure undergoes positive changes. Training is especially useful for improving the cardiovascular system in cyclic outdoor sports.

Respiratory system

The respiratory system includes the nasal cavity, larynx, trachea and lungs. The structural and functional unit of the gas exchange apparatus is the acinus (bunch). It includes the following elements: bronchi; bronchioles; alveoli located in the alveolar passages; capillary network surrounding the alveoli; veins that carry arterial blood. The total surface of the alveoli (pulmonary vesicles) is 50 times the surface of human skin and is more than 100 square meters. m.

Respiration is a continuous biological process of gas exchange, which has a reflex nature; regulated by the CNS. Respiration is divided into external (pulmonary) and internal (tissue).

The entry of air into the lungs (inhalation) is the result of contraction of the respiratory muscles and an increase in lung capacity. Exhalation occurs due to relaxation of the respiratory muscles.

Features of breathing. Energy costs for physical work are provided by biochemical processes occurring in the muscles as a result of oxidative reactions, for which oxygen is constantly needed. During muscular work, the functions of respiration and blood circulation are enhanced to increase gas exchange. The joint work of the respiratory, blood and circulatory systems for gas exchange is assessed by a number of indicators: respiratory rate, tidal volume, pulmonary ventilation, lung capacity, oxygen demand, oxygen consumption, blood oxygen capacity, etc.

The average respiratory rate at rest is 15-18 cycles per minute. One cycle consists of inhalation, exhalation and respiratory pause. In women, the respiratory rate is 1-2 cycles higher. In athletes at rest, the respiratory rate is reduced to 6-12 cycles per minute due to an increase in the depth of breathing and tidal volume. During physical work, the respiratory rate increases: for example, skiers and runners up to 20-28, swimmers 36-45 cycles per minute.

Vital capacity (VC) - the maximum volume of air that a person can exhale after a maximum breath. Average VC values ​​are 3800-4200 ml in men and 3000-3500 ml in women. VC depends on age, weight, height, gender, the state of physical fitness of a person and other factors. In people with insufficient physical development and those with diseases, this value is less than the average; in people involved in physical culture, it is higher, and in athletes it can reach 7000 ml or more in men and 5000 ml or more in women. A well-known method for determining VC is spirometry (a spirometer is a device that allows you to determine VC).

Systematic training by means of physical culture and sports not only stimulates the development of the cardiovascular and respiratory systems, but also contributes to a significant increase in the level of oxygen consumption by the body as a whole.

Physical activity has a dual training effect: it increases resistance to oxygen starvation and, by increasing the power of the respiratory and cardiovascular systems, contributes to better oxygen utilization.

Digestion and excretion system

Digestion is the preliminary stage of metabolism, as a result of which it becomes possible for the absorption of nutrients through the walls of the digestive tract and their entry into the blood or lymph. In the digestive apparatus, complex physicochemical transformations of food occur: from the formation of a food bolus in the oral cavity to the absorption and removal of its undigested residues. These processes can be carried out using the functions of the digestive apparatus - motor, suction and secretory.

The digestive system includes the following departments:

1) oral cavity. In it, with the help of the tongue, teeth, palate and salivary glands, the initial mechanical processing of food takes place;

2) throat. A functional feature is that in the pharynx there is a cross of the respiratory and digestive tracts. The act of swallowing is carried out;

3) esophagus. Performs the following functions:

Passing food through the chest cavity

Control of the size of the food bolus and food masses in general, because food can be returned from the esophagus consciously.

4) stomach. There are two functional parts - digesting and evacuation;

5) small intestine. Consists of duodenum, jejunum and ileum. Further digestion and absorption of nutrients occurs;

6) large intestine. It consists of the ascending and descending colons, the transverse colon, the sigmoid colon, the caecum, and the rectum. The large intestine performs the following functions: reabsorption of water, the formation of feces, their evacuation from the body.

The gallbladder, spleen, pancreas, and liver are also directly involved in the process of digestion.

excretory system

The main function of the excretory system is to remove metabolic products from the body. They form the excretory system of the kidney, ureter and bladder. Some metabolic products are excreted through the skin, lungs and gastrointestinal tract. With the help of the kidneys, the body maintains the acid-base balance (pH), the necessary exchange of water and salts, and homeostasis.

Nervous system

Consists of central (brain and spinal cord) and peripheral sections. The CNS processes heterogeneous information coming through the sensory fibers of the peripheral nerves from the receptors of the skin, mucous membranes, muscles, tendons and internal organs, and also the body's response is programmed, carried out using signals sent to the muscles, glands, blood vessels and internal organs through motor and autonomic fibers of peripheral nerves. The central nervous system regulates and ensures the functional unity of all human organs and systems and communicates the body with the environment.

Receptors and analyzers

Analyzers - a system of specialized nerve formations that perceive the information received. Analyzers are distinguished: exteroceptive (for example, hearing, vision, smell, taste, touch); interoceptive, controlling the state of the internal environment of the body - under their influence is the vestibular apparatus, the musculoskeletal system (ODA), the level of blood pressure, etc.

The analyzer consists of three sections: the receptor, the conductive part and the center in the brain.

Receptors are the nerve endings of sensory nerves. This is the main source of information about the surrounding world (for example, vision, smell, etc.)

If any analyzer is disturbed during training, the capabilities of other analyzers expand compensatory (for example, the blind have more finely developed sense of touch, hearing and other senses).

Endocrine system

Endocrine glands (endocrine glands) secrete biologically active substances - hormones. The morphological feature of these glands is the absence of specialized excretory ducts. Waste products of the endocrine system are excreted directly into the blood, lymph or cerebrospinal fluid.

The leading hormonal system of the body is the hypothalamus - pituitary - adrenal glands. The endocrine glands included in this system are the most important regulators of the physiological processes that underlie the integral reactions of the body.

The endocrine glands include: thyroid, parathyroid, goiter, adrenal glands, pancreas, pituitary gland, gonads and a number of others.

The external environment and its impact on the human body

The following factors affect the human body: 1) natural - barometric pressure, gas composition and air humidity, temperature, solar radiation; 2) biological factors of plant and animal environment; 3) social environment. They are inextricably linked to environmental issues.

Human ecology studies the patterns of human interaction with nature, the problems of maintaining and strengthening health. Man depends on living conditions in the same way that nature depends on man.

Human functional activity

The functional activity of a person is characterized by the contraction of the muscles of the heart, the movement of the body in space, the movement of the eyeballs, swallowing, breathing, the motor component of speech, i.e. various motor acts.

The fundamental action of man is labor (as you know, it was he who created man). There are two main types of labor activity: physical labor and mental labor.

Hypokinesia and hypodynamia

Hypodynamia is a limitation of motor activity, due to the peculiarities of lifestyle, professional activity.

Hypokinesia is a state of the body due to lack of motor activity.

Both of these conditions are characterized by muscle atrophy, a general decrease, a weakening of the functional capabilities of the cardiovascular system and the respiratory system, and a violation of the central nervous system. The lack of systematic physical exercises leads to negative changes in the activity of the higher parts of the brain, its subcortical structures and formations. As a result, immunity decreases, increased fatigue occurs, sleep is disturbed, and mental and physical performance decreases.

The socio-biological foundations of physical culture are principles of interaction of social and biological patterns in the process of mastering the values ​​of physical culture by a person. Naturally - the scientific foundations of physical culture - a complex of biomedical sciences (anatomy, physiology, biology, biochemistry, hygiene, etc.). Anatomy and physiology are the most important biological sciences about the structure and functions of the human body. Man obeys the biological laws inherent in all living beings. However, it differs from representatives of the animal world not only in its structure, but also in its developed thinking, intellect, speech, features of social and living conditions of life and social relationships.

Human organism- a well-coordinated single self-regulating and self-developing biological system, the functional activity of which is due to the interaction of mental, motor and vegetative reactions to environmental influences, which can be both beneficial and detrimental to health. All organs are interconnected and interact. Violation of the activity of one organ leads to disruption of the activity of others. A distinctive feature of a person is a conscious and active influence on external natural and social conditions that determine the state of people's health, their performance, life expectancy and fertility (reproductivity).

Without knowledge about the structure of the human body, about the patterns of functioning of individual organs and systems of the body, about the features of the flow of complex processes of its life, it is impossible to organize the process of forming a healthy lifestyle and physical training of the population, including young students.

Every person inherits from parents, congenital, genetically determined traits and characteristics that largely determine individual development in the process of his later life. It should be noted that over the past 100-150 years in a number of countries there has been an early morphofunctional development of the body in children and adolescents. This phenomenon is called acceleration (lat. acceleration - acceleration), it is associated not only with the acceleration of growth and development of the body in general, but also with the earlier onset of puberty, accelerated development of sensory (lat. sensus - feeling), motor abilities and mental functions . Therefore, the boundaries between age periods are rather arbitrary and this is due to significant individual differences, in which the "physiological" age and "passport" age do not always coincide.

Usually, adolescence (16-21 years) is associated with a period of maturation, when all organs, their systems and apparatus reach their morphological and functional maturity. Mature age (22-60 years) is characterized by minor changes in the structure of the body, and the functionality of this rather long period of life is largely determined by the characteristics of lifestyle, nutrition, physical activity. The elderly (61-74 years) and senile (75 years and more) are characterized by physiological processes of restructuring: a decrease in the active capabilities of the body and its systems - immune, nervous, circulatory, etc. A healthy lifestyle, active motor activity in the process of life significantly slows down the process aging.

The vital activity of the organism is based on the process of automatic maintenance of vital factors at the required level, any deviation of which leads to the immediate mobilization of mechanisms that restore this level (homeostasis).

If the work excitatory load is not repeated after a certain period, then the phase of increased performance gradually passes. Another thing is if the functional load is repeated systematically. After some time, the increased level of production of plastic materials, in the mastered phase of exaltation, becomes constant and initial for further growth in working capacity. The exercised organ increases its mass and reaches a higher structural and functional perfection. Updated tissue better adapts to new external stimuli. It should be remembered that the central nervous system (CNS), sending nerve impulses along the motor fibers to the muscles and internal organs, causes their activity.

In turn, the excitation of receptors (sensors) located in these organs and tissues (including muscles) causes a flow of sensitive impulses directed to various parts of the central nervous system, including the cerebral cortex.

Receptors can also be called analyzers. There are analyzers: visual, auditory, olfactory, gustatory, tactile, vestibular, proprioceptive.

Tactile the analyzer provides the perception of touch sensations, its place, strength, duration.

Vestibular the analyzer gives a sense of the position of the body in space, as well as acceleration (both linear and angular) and, therefore, allows you to determine a number of parameters of the movement of the whole body

proprioceptive the analyzer allows you to determine the degree of muscle tension, the relative position of the body links, the speed and acceleration of movements, their amplitude; it is decisive in motor activity, gives information about the movements performed.

The central nervous system, mobilizing muscle contractions, in turn, under the influence of impulses coming from the muscles and internal organs, improves its function.

Decreased for a long time muscle activity sharply limits the flow of sensitive impulses entering the central nervous system. In the absence of such excitatory impulses, the functional level of both the central nervous system and peripheral organs decreases. Therefore, physical activity has a beneficial effect on the central nervous system, forcing the nerve centers to work, including self-healing processes and thereby contributing to the improvement of the central nervous system.

Speaking about the influence of motor activity on the central nervous system, one cannot fail to say that active muscular activity causes an increase in the activity of the cardiovascular, respiratory and other body systems. In any activity of the body, all its organs and systems act in concert, in close unity. This relationship is carried out by humoral (fluid) regulation and the nervous system.

Humoral regulation is carried out through the blood through special chemicals - hormones secreted by the endocrine glands, the ratio of oxygen and carbon dioxide concentrations, and using other mechanisms. When carbohydrates pass into the blood from the digestive organs, where they enter with food, their excess under the influence of the hormone insulin produced by the pancreas, are converted into glycogen and stored in the body as a reserve.

Under influence - a hormone secreted into the blood by the adrenal glands in the pre-start state, or during intense muscular work, glycogen is converted into glucose and enters the bloodstream to nourish actively working muscles. An increase in the concentration of carbon dioxide in the blood, which occurs during muscular work, affects the respiratory center and leads to an increase in the depth and frequency of breathing. Strengthening the activity of the heart and, in connection with this, an increase in blood pressure affects special nerve formations in the vessels (baroreceptors) and promote vasodilation.

Circulatory system.

The heart is the main organ of the circulatory system, it is a hollow muscular organ that performs rhythmic contractions, due to which the process of blood circulation in the body occurs. The heart is an autonomous, automatic device, but its work is corrected by direct and feedback connections coming from various organs and systems of the body.

The heart is connected with the central nervous system, which has a certain regulatory effect on its work.

The cardiovascular system consists from the large and small circles of blood circulation. The left half of the heart serves a large circle of blood circulation, the right - a small one. The systemic circulation starts from the left ventricle of the heart, passes through the tissues of all organs and returns to the right atrium. From the right atrium, blood passes into the right ventricle, and from there, from the right ventricle, the pulmonary circulation begins, which passes through the lungs, where venous blood, giving off carbon dioxide and being saturated with oxygen, turns into arterial blood and goes to the left atrium. From the left atrium, blood passes into the left ventricle and from there again into the systemic circulation.

The activity of the heart consists in the rhythmic change of cardiac cycles, consisting of three phases: atrial contraction, ventricular contractions, and general relaxation of the heart.

Active physical activity of a person has a training effect on the heart and the entire cardiovascular system. Perceiving regular training loads, the heart muscle develops and improves. As a rule, the mass of the heart muscle increases, and the size of the heart also increases. Competitive athletes tend to have a "dilated" heart, which can be seen by doctors on a chest X-ray.

Indicators of the health of the heart are, first of all, the pulse rate , blood pressure, systolic blood volume, minute volume of blood. Statistics show that the volume of the heart of a trained person is 1.5-2 times greater than that of an untrained person.

The pulse rate of trained people is significantly lower than that of untrained people: men: 50 - 60 beats per minute. 70-80 beats per minute in untrained; women: 60 - 70 beats per minute. in trained, 75 - 85 beats per minute. in the untrained. The frequency of the pulse at rest (in the morning, lying down, on an empty stomach) becomes less frequent due to an increase in the power of each contraction. Reducing the pulse rate increases the absolute pause time for the rest of the heart and for the processes of recovery of the heart muscle.

Blood pressure builds up the force of contractions of the ventricles of the heart and the strength of the walls of blood vessels. Blood pressure is measured in the brachial artery. Distinguish the maximum ( systolic) the pressure that is created during the contraction of the left ventricle (systole) and the minimum ( diastolic ) pressure - the pressure that is noted during the relaxation of the left ventricle (diastole). The pressure is maintained by the elasticity of the walls of the distended aorta and other large arteries. Normal pressure at rest: 120\70 mm. rt. pillar.

Physical work contributes to the expansion of blood vessels, reducing the tone of their walls, the free passage of blood; mental work, as well as neuro-emotional stress, leads to vasoconstriction, an increase in the tone of their walls, and even to spasms.

This reaction is especially characteristic of the vessels of the heart and brain. Prolonged intense mental work, frequent neuro-emotional stress, unbalanced with active movements and physical exertion, can lead to a deterioration in the nutrition of these most important organs, a persistent increase in blood pressure, which is called hypertension. A decrease in blood pressure at rest also indicates the disease, which may be the result of a weakening of the activity of the heart muscle.

Due to the denser network of blood vessels and their high elasticity in athletes, as a rule, the maximum pressure is slightly lower than normal.

In a trained person, when performing physical work, blood pressure rises to 200 mm. rt. pillar and can hold on for a long time. In an untrained person, the pressure rises to 200 mm. rt. the column then decreases due to heart fatigue. If intensive work continues for a long time, fainting may occur. After work or the termination of the training load in a trained person, blood pressure is quickly restored to normal (2-3 minutes); in an untrained person, the pressure remains elevated for a long time.

The limiting heart rate in trained people during exercise is at the level of 200 - 240 beats per minute. An untrained heart cannot reach such a frequency.

Systolic blood volume - the amount of blood ejected by the left ventricle of the heart with each contraction. Minute volume of blood is the amount of blood ejected by the ventricle in one minute.

Systolic blood volume in athletes is about 200 ml, in untrained - 130 ml. Minute volume for athletes is 35 - 42 liters, untrained - 22 - 25 liters. The greatest systolic volume is observed at a heart rate of 130 to 180 beats per minute. At a heart rate above 180 beats per minute, systolic volume begins to decline dramatically. Therefore, the best opportunities for training the heart occur during physical exertion, when the pulse rate is in the range of 130-180 beats per minute.

With intense physical work, the heart of an untrained person cannot show the efficiency that provides nutrition to the working organs. To perform a fast run, for example, you need to pump 30 l / min. And the limit of the possibility of an untrained heart is 25 l / min. Therefore, an untrained person cannot run fast for a long time; prolonged intensive muscular work can cause such a person to faint as a result of a lack of oxygen and nutrients.

At rest, the blood makes a complete circulation in 21-22 seconds, during physical work in 8 seconds. and less. As a result of an increase in speed, the supply of tissues with oxygen and nutrients increases significantly.

The movement of blood through the veins is facilitated by the activity of the surrounding muscles (muscle pump). The more often the muscles contract and relax, the more complete their relaxation and contraction, the more help the muscle pump renders to the heart. It works especially effectively when walking, running, skiing, skating, swimming, rowing, etc. The muscle pump promotes faster rest of the heart after intense physical activity.

Respiratory system.

Breathing is not just "inhale - exhale". Respiration is a complex of physiological processes carried out by the respiratory apparatus and the circulatory system, which provides oxygen to the tissues of the body and removes carbon dioxide from them. The respiratory apparatus of a person consists of the lungs located in the cavity of the chest; airways - nasal cavity, nasopharynx, pharynx, trachea, bronchi; chest and respiratory muscles. Branching bronchi end with the smallest closed alveolar passages, in the walls of which there are a large number of spherical protrusions - pulmonary vesicles (alveoli). Each alveolus is surrounded by a dense network of blood capillaries. The total surface of the pulmonary vesicles is more than 100 sq.m.

The lungs are located in a hermetically sealed chest cavity. They are covered with a thin smooth shell - the pleura, the same shell lines the inside of the chest cavity.

The expansion of the chest cavity is carried out as a result of the activity of the respiratory muscles. Exhalation at rest is passive; when the muscles are relaxed, the exhalation of the chest cell decreases under the influence of gravity and atmospheric pressure.

should be distinguished: external breath, at which oxygen from the atmospheric air passes into the blood, and carbon dioxide from the blood into the atmospheric air; transport of gases by the blood; and tissue respiration- the consumption of oxygen by cells and the release of carbon dioxide by them as a result of biochemical reactions associated with the formation of energy to ensure vital processes.

External respiration is carried out in the alveoli of the lungs, where molecules of oxygen and carbon dioxide pass through the semi-permeable walls of the alveoli and capillaries in hundredths of a second.

After the transfer of oxygen by the blood to the tissues, oxygen passes from the blood into the interstitial fluid and from there to the tissue cells, where it is used to ensure metabolic processes. Carbon dioxide, which is intensively produced in the cells, passes into the interstitial fluid and then into the blood and through the lungs is excreted from the body.

The joint performance of the respiratory and circulatory systems is assessed by a number of indicators: respiratory rate, tidal volume, pulmonary ventilation, lung capacity, oxygen demand, oxygen consumption.

Breathing rate on average at rest 12-20 cycles per minute. One cycle consists of inhalation, exhalation and respiratory pause. In women, the respiratory rate is 1-2 cycles higher. In athletes, the respiratory rate is reduced to 8 - 12 cycles per minute. During physical work, the respiratory rate increases in skiers and runners up to 20 - 28, swimmers - yes 36 - 45. There have been cases of an increase in respiratory rate up to 75 cycles per minute.

Tidal volume - the amount of air passing through the lungs during one respiratory cycle. At rest, the volume is 350-800 ml. With intensive work, the volume increases to 2.5 liters.

Pulmonary ventilation is the volume of air that passes through the lungs in one minute. The value of pulmonary ventilation is determined by multiplying the value of the tidal volume by the respiratory rate. At rest, pulmonary ventilation is 5-9l. But it can increase during competitions by 10-20 times.

Vital capacity of the lungs(VEL) the maximum amount of air a person can exhale after a maximum inhalation. On average, it is 3800-4200 ml. in men and 3000-3500 in women.

oxygen request - the amount of oxygen required by the body in one minute for oxidative processes at rest or to ensure work of varying intensity. Oxygen demand corresponds to the amount of energy consumption for the work performed. At rest, 250-300 ml of oxygen per minute is required to ensure the vital activity of the body. Intensive work requires 5-6 liters of oxygen per minute.

Total (total oxygen) request- the amount of oxygen necessary to ensure the performance of all the work ahead.

Oxygen consumption - the amount of oxygen actually used by the body at rest or while performing any work in one minute.

Maximum oxygen consumption (MOC) is the maximum amount of oxygen that can be absorbed by the body during extremely difficult work for it. BMD is an important criterion for the functional state of respiration and circulation.

The usual level of IPC is 2-3.5 l / min. Athletes have 4-6 l / min or more. It is rational to calculate the relative IPC per kilogram of body weight.

IPC is an indicator aerobic(oxygen) performance of the organism, i.e. his ability to perform intense physical work with a sufficient amount of oxygen entering the body. It is believed that in order to increase the level of aerobic performance, training loads should be performed with a heart rate of 150-180 beats / min.

oxygen debt - the amount of oxygen necessary for the oxidation of metabolic products accumulated during physical work. With prolonged intensive work, a total oxygen debt arises, which is eliminated after the end of work. The value of the maximum possible total oxygen debt has a limit (ceiling). In untrained people, it is within 10 liters, in trained people it can reach 20 liters or more. Oxygen debt occurs when a person's oxygen demand is above the oxygen consumption ceiling.

When less oxygen enters tissue cells than is needed to fully meet energy needs, oxygen starvation, or hypoxia, occurs. The causes of hypoxia are different: external- gas pollution, rise to a height: at sea level, the partial pressure of oxygen in the atmospheric air is 159 mm Hg. Art., at an altitude of 5000 m - up to 75-80 mm Hg. st; internal- the state of the respiratory apparatus, the permeability of the walls of the alveoli and capillaries, the number of red blood cells in the blood and the percentage of hemoglobin in them, the permeability of the membranes of tissue cells.

Path of oxygen from pulmonary alveoli to cellular mitochondria(formations in cells that absorb oxygen) is quite complex, the magnitude of its flow depends on the perfection of the function of each of the sections of this path (lungs, blood, cardiovascular system, tissues and, finally, the cell). This path of oxygen movement to the cell, and from it to the lungs, is called oxygen cascade. Systematic physical training not only develops the functional abilities of the respiratory organs, but also improves the function of all parts of the path along which oxygen follows. Oxygen nutrition of muscles has its own characteristics.

Contracted muscles squeeze the capillaries, slowing down blood flow and oxygen supply. The delivery of oxygen to the working muscle takes over myoglobin - respiratory pigment of muscle cells. Its role is also important because only muscle tissue is capable of increasing oxygen consumption a hundred times during the transition from rest to intensive work. Improving the entire oxygen cascade during physical training significantly expands the body's ability to consume oxygen and creates the basis for the elimination of hypoxic phenomena in the organs and tissues of the human body.

Organs differ significantly in their ability to tolerate hypoxia of varying duration. The cerebral cortex is one of the organs most sensitive to hypoxia. The skeletal muscles are much less sensitive to oxygen deficiency. Even two-hour complete oxygen starvation is not reflected on it.

An important role in the regulation of oxygen metabolism both in organs and tissues, and in the body as a whole has carbon dioxide. There are strictly defined relationships between the concentration of carbon dioxide in the blood and the delivery of oxygen to tissues. A change in the content of carbon dioxide in the blood affects the central and peripheral regulatory mechanisms that improve the supply of oxygen to the body, and serves as a powerful regulator in the fight against hypoxia.

Bone system.

Humans have over 200 bones(85 paired and 36 unpaired), which, depending on the form and function, are divided into: tubular(bones of limbs); spongy(perform mainly protective and supporting functions - ribs, sternum, vertebrae, etc.); flat(bones of the skull, pelvis, limb belts); mixed(base of skull).

Each bone contains all types of tissues, but bone, which is a type of connective tissue, predominates. The composition of the bone includes organic and inorganic substances. Inorganic (65-70% dry weight) are mainly phosphorus and calcium. Organic (30-35%) are bone cells, collagen fibers. Elasticity, elasticity of bones depends on the presence of organic substances in them, and hardness is provided by mineral salts. The combination of organic substances and mineral salts in living bone gives it an extraordinary strength and elasticity, which can be compared with the hardness and elasticity of cast iron, bronze or copper. The bones of children are more elastic and resilient - organic substances predominate in them, while the bones of older people are more fragile - they contain a large amount of inorganic compounds.

With the systematic performance of significant in terms of volume and intensity of static and dynamic exercises, the bones become more massive, well-defined thickenings are formed in the places of muscle attachment - bone protrusions, tubercles and ridges. There is an internal restructuring of the compact bone substance, the number and size of bone cells increase, the bones become much stronger.

Human skeleton consists of the spine, skull, chest, limb girdles and skeleton of free limbs.

Spine, consisting of 33-34 vertebrae, has five departments: cervical (7 vertebrae), thoracic (12), lumbar (5), sacral (5), coccygeal (4-5). The spinal column allows you to bend forward and backward, to the sides, rotational movements around the vertical axis. Normally, it has two forward bends (cervical and lumbar lordosis) and two backward bends (thoracic and sacral kyphosis). These bends are of functional importance when performing various movements (walking, running, jumping, etc.), they weaken shocks, blows, etc., acting as a shock absorber.

Rib cage Formed by 12 thoracic vertebrae, 12 pairs of ribs, and the sternum (sternum), it protects the heart, lungs, liver, and part of the digestive tract.

Scull protects from external influences the brain and centers of the sense organs. It consists of 20 paired and unpaired bones, connected to each other motionlessly, except for the lower jaw. The skull is connected to the spine with the help of two condyles of the occipital bone with the upper cervical vertebra, which has corresponding articular surfaces.

Skeleton of the upper limb formed by the shoulder girdle, consisting of two shoulder blades and two collarbones, and a free upper limb, including the shoulder, forearm and hand. The shoulder is one humeral tubular bone; the forearm is formed by the radius and ulna; the skeleton of the hand is divided into the wrist (8 bones arranged in two rows), the metacarpus (5 short tubular bones) and the phalanges of the fingers (14 phalanges).

Skeleton of the lower limb formed by the pelvic girdle (2 pelvic bones and the sacrum) and the skeleton of the free lower limb, which consists of three main sections - the thigh (one femur), the lower leg (tibia and fibula) and the foot (tarsus - 7 bones, metatarsus - 5 bones and 14 phalanges).

All bones of the skeleton are connected through joints, ligaments and tendons. joints- movable joints, the area of ​​​​contact of the bones in which is covered with an articular bag of dense connective tissue, fused with the periosteum of the articulating bones. The joint cavity is hermetically sealed, it has a small volume, depending on the shape and size of the joint. Articular fluid reduces friction between surfaces during movement, and the smooth cartilage that covers the articular surfaces performs the same function. Flexion, extension, adduction, and abduction can occur in the joints.

So, musculoskeletal system consists of bones, ligaments, muscles, muscle tendons. Most of the articulating bones are connected by ligaments and muscle tendons, forming the joints of the limbs, spine, etc. The main functions are to support and move the body and its parts in space. With systematic exercise and sports, the joints develop and strengthen, the elasticity of ligaments and muscle tendons increases, and flexibility increases. And vice versa, in the absence of movements, the articular cartilage loosens and the articular surfaces that articulate the bones change, pain appears, and inflammatory processes occur.

Muscular system provides human movement, vertical position of the body, fixation of internal organs in a certain position, respiratory movements, increased blood circulation and lymph circulation (muscle pump), thermoregulation of the body along with other systems.

A person has more than 600 muscles, which is 35~40% of body weight; athletes have 50% or more. The mechanical activity of muscles occurs as a result of the ability of muscle fibers to go into a state of excitation, i.e. into an active state under the influence of biocurrents going to the muscles along the nerve fibers.

The work of muscles is carried out due to their tension or contraction.

The tension that occurs without changing the length of the muscle characterizes the static work of the muscles. Muscle contraction, which occurs with a change in their length, characterizes the dynamic work of the muscles. Most often, muscles work in a mixed (auxotonic) mode, simultaneously tensing and contracting in length. The force developed by a muscle depends on the number of muscle fibers, their cross section, as well as on the elasticity and initial length of an individual muscle. Systematic physical training increases muscle strength precisely by increasing the number and thickening of muscle fibers and by increasing their elasticity.

There are two types of muscles: smooth(involuntary) and striated(arbitrary). Smooth muscles are located in the walls of the blood vessels of some internal organs. They constrict or dilate blood vessels, move food through the gastrointestinal tract, and contract the walls of the bladder. Striated muscles are all skeletal muscles that provide a variety of body movements. The striated muscles also include the heart muscle, which automatically ensures the rhythmic work of the heart throughout life.

Trunk muscles include the muscles of the chest, back and abdomen: pectoralis major muscle, external oblique muscle of the abdomen, rectus abdominis, intercostal muscles, trapezius muscle, rhomboid muscle, erector trunk muscle, latissimus dorsi muscle.

Muscles of the upper limbs: biceps brachii (biceps), deltoid, triceps brachii (triceps).

Muscles of the lower extremities: rectus femoris (quadriceps), sartorius, tender, biceps, gluteus maximus. Leg muscles: calf, Achilles tendon.

Digestive system.

Digestion- This the process of physically and chemically processing food and converting it into simpler and more soluble compounds that can be absorbed, carried by the blood and absorbed by the body. The digestive system (alimentary tract) consists of the oral cavity with three pairs of large salivary glands, pharynx, esophagus, stomach and small intestine, which includes the duodenum (in which the ducts of the gallbladder and pancreas open), jejunum and ileum. The tract ends with the large intestine. In each section of the digestive system, specialized food processing operations occur, associated with the presence of specific enzymes in them, which gradually break down food.

In early adolescence (16-17 years), the digestive system matures, its regulatory mechanisms improve and stabilize.

excretory organs play an important role in maintaining the constancy of the internal environment: they remove metabolic products from the body that cannot be used, excess water and salts. The excretion processes involve the lungs, intestines, skin and kidneys. The lungs remove carbon dioxide, water vapor, and volatile substances from the body. Heavy metal salts and excess unabsorbed nutrients are removed from the intestines with feces. The sweat glands of the skin secrete water, salts, organic substances. At rest, a person loses 20 - 40 ml of sweat per hour. Their activity is enhanced by intense muscular work and an increase in ambient temperature.

The main role in the excretory processes belongs to the kidneys, which remove water, salts, ammonia, urea, uric acid from the body, restoring the constancy of the osmotic properties of the blood. Through the kidneys, some toxic components that are formed in the body when taking medicinal and other substances are removed. The kidneys maintain a certain constant blood reaction. In the period of early adolescence, the excretory system, in terms of growth and development, reaches the level characteristic of an adult.

endocrine system plays an important role in the regulation of body functions. The organs of this system are endocrine glands- secrete special substances - hormones(Greek horman - excite), affecting the metabolism, structure and functions of organs and tissues of the body. Endocrine glands secrete hormones directly into the blood, so they are called endocrine glands (Greek endon - inside, krinein - secrete). The endocrine system is formed by: pituitary gland, epiphysis, thyroid and parathyroid glands, thymus and pancreas, adrenal glands and gonads.

The endocrine glands are functionally closely interconnected and work as a whole - the endocrine system. It is under the control of the nervous system.

All endocrine glands are small in size and mass, richly supplied with blood vessels and constantly secrete small portions of hormones.

Pituitary located at the base of the medulla oblongata. It regulates the growth processes of the body, fat, protein, carbohydrate and water-salt metabolism; as a whole determines physical, sexual and mental development. The formation of the gland occurs during the period of childhood, reaches the level characteristic of an adult by the age of 15-16.

Thyroid, functions in conjunction with the parathyroid glands, is located in the cervical region and regulates all types of metabolism, affects physical, sexual and mental development. Lack of gland hormones in early childhood leads to the development of cretinism, excess to Graves' disease. In its development, it reaches the level characteristic of an adult by the age of 15-16.

Thymus located in the chest cavity. This is the gland of childhood and youth, it has a small mass at 6-15 years. After 15 years, its involution (reverse development) is observed. The period of the most intensive growth of the organism is associated with the activity of the gland. In addition, it is the central organ of immunity. Violation of it leads to serious deviations in metabolism.

Pancreas located in the abdominal cavity behind the stomach. The hormones of this gland are involved in the regulation of the metabolism of carbohydrates and fats. Their deficiency leads to diabetes. The maturation of the pancreas occurs early, by the age of 10, in all respects, it reaches the level characteristic of an adult.

adrenal glands located above the kidneys. Some adrenal hormones (corticoids) are involved in the regulation of carbohydrate and water-salt metabolism, as well as immunity, while others (adrenaline) serve as a mobilizer of all body functions under stress. The greatest jump in the development of the adrenal glands occurs during puberty. They reach the level characteristic of an adult by the age of 15-16.

Sex glands. Male sex glands (testes) are located outside the body in the scrotum, female (ovaries) - in the cavity of the small pelvis. The testicles produce male sex hormones (androgens) and male and sex cells (spermatozoa). The ovaries produce female sex hormones (estrogens) and female sex cells (eggs). Sex hormones throughout life have a powerful effect on body formation, metabolism and sexual behavior. The sex glands reach their greatest development in adolescence. In the period of early youth (16-17 years), their development reaches a peak. It is believed that by this period the gonads have matured, and the body is prepared for childbearing function.

epiphysis (pineal gland) is part of the diencephalon. Its main functions are the regulation of sexual development (its inhibition) and the sleep-wake life cycle. The epiphysis is the gland of childhood. It reaches its greatest development at 6-7 years. Further, its reverse development begins. In adolescence and adolescence, the functions of the epiphysis are sharply reduced.