Methods for assessing the state of the cardiovascular system. Method for determining the functional state of the cardiovascular system
7.3.
Determination of the functional state of the cardiovascular system in athletes
Determining the functional capacity of the cardiovascular system (CVS) is absolutely necessary for assessing the overall fitness of an athlete or athlete, since blood circulation plays an important role in satisfying the increased metabolism caused by muscle activity.
A high level of development of the functional ability of the circulatory apparatus, as a rule, characterizes a high overall performance of the body.
In a comprehensive methodology for studying the cardiovascular system, much attention in sports medicine is paid to studying the dynamics of its indicators in connection with the performance of physical activity, and a fairly large number of functional tests with physical activity have been developed in this direction.
7.3.1. General clinical research methods
When examining the CCC, anamnesis data are taken into account. General information is entered into the research protocol:
Surname, name, patronymic of the subject;
Age, main sport, category, length of service, period of training and its features, information about the last training session, well-being, complaints.
On external examination pay attention to the color of the skin, the shape of the chest, the location and nature of the apex beat, the presence of edema.
Palpation the location of the apex beat (width, height, strength), painful tremors in the chest area, and the presence of edema are determined.
By using percussion(tapping) the borders of the heart are studied. If the doctor finds a pronounced displacement of the borders of the heart during percussion, then the athlete must be subjected to a special x-ray examination.
auscultation(listening) is recommended to be carried out in various positions of the subject: on the back, on the left side, standing. Listening to tones and noises is associated with the work of the valvular apparatus of the heart. The valves are located "at the entrance" and "at the exit" of both ventricles of the heart. The atrioventricular valves (the mitral valve in the left ventricle and the tricuspid valve in the right ventricle) prevent backflow (regurgitation) of blood into the atria during ventricular systole. The aortic and pulmonary valves, located at the base of large arterial trunks, prevent regurgitation of blood into the ventricles during diastole.
Atrioventricular valves are formed by membranous sheets (cusps) hanging down into the ventricles like a funnel. Their free ends are connected by thin tendon ligaments (chord threads) to the papillary muscles; this prevents the valve leaflets from wrapping into the atria during ventricular systole. The total surface of the valves is much larger than the area of the atrioventricular orifice, so their edges are tightly pressed against each other. Thanks to this feature, the valves close reliably even with changes in ventricular volume. The aortic and pulmonic valves are arranged somewhat differently: each of them consists of three crescent-shaped pockets surrounding the mouth of the vessel (therefore they are called semilunar valves). When the semilunar valves are closed, their leaflets form a figure in the form of a three-pointed star. During diastole, blood flows behind the valve leaflets and swirl behind them (Bernoulli effect), as a result, the valves close quickly, due to which the regurgitation of blood into the ventricles is very small. The higher the blood flow velocity, the tighter the cusps of the semilunar valves close. The opening and closing of the heart valves is associated primarily with a change in pressure in those cavities of the heart and vessels that are delimited by these valves. The sounds resulting from this, and create heart sounds. With heart contractions, sound frequency oscillations (15-400 Hz) occur, which are transmitted to the chest, where they can be heard either simply with the ear or with a stethoscope. When listening, two tones can be distinguished: the first of them occurs at the beginning of systole, the second - at the beginning of diastole. The first tone is longer than the second, it is a dull sound of a complex timbre. This tone is mainly due to the fact that at the moment of the slamming of the atrioventricular valves, the contraction of the ventricles is, as it were, sharply inhibited by the incompressible blood filling them. As a result, vibrations of the walls of the ventricles and valves occur, which are transmitted to the chest. The second tone is shorter. Associated with the impact of the leaflets of the semilunar valves against each other (which is why it is often called a valvular tone). The vibrations of these valves are transmitted to the blood columns in large vessels, and therefore the second tone is better heard not directly above the heart, but at some distance from it along the blood flow (the aortic valve is auscultated in the second intercostal space on the right, and the pulmonary valve - in the second intercostal space on the left). The first tone, on the contrary, is better auscultated directly above the ventricles: in the fifth intercostal space, the left atrioventricular valve is heard along the mid-clavicular line, and the right one along the right edge of the sternum. This technique is a classic method used in the diagnosis of heart defects, assessment of the functional state of the myocardium.
The importance of the study of the CCC is attached to the correct assessment of the pulse. Pulse (from Latin pulsus - push) is the jerky displacement of the walls of the arteries when they are filled with blood ejected during left ventricular systole.
The pulse is determined using palpation one of the peripheral arteries. Usually, the pulse is counted on the radial artery in 10-second time intervals 6 times. During exercise, it is not always possible to determine and accurately calculate the pulse on the radial artery, so it is recommended to count the pulse on the carotid artery or on the projection area of the heart.
In an adult healthy person, the heart rate (HR) at rest ranges from 60 to 90 beats per minute. Heart rate is influenced by body position, sex and age of a person. An increase in heart rate of more than 90 beats per minute is called tachycardia, and a heart rate of less than 60 beats per minute is called bradycardia.
Rhythmic the pulse is considered if the number of beats in 10-second intervals does not differ by more than 1 beat (10, 11, 10, 10, 11, 10). Pulse arrhythmia- significant fluctuations in the number of heartbeats for 10-second time intervals (9, 11, 13, 8, 12, 10).
Filling the pulse rated as good if, when applying three fingers to the radial artery, the pulse wave is well palpable; how satisfactory with a slight pressure on the vessel, the pulse is easily counted; as poor filling - the pulse is hardly caught when pressed with three fingers.
Pulse voltage is the state of the tone of the artery and is evaluated as soft pulse characteristic of a healthy person, and solid- in violation of the tone of the arterial vessel (with atherosclerosis, high blood pressure).
Information about the characteristics of the pulse is entered in the appropriate columns of the study protocol.
Arterial pressure(BP) is measured with a mercury, membrane or electronic tonometer (the latter is not very convenient in determining blood pressure during the recovery period due to the long inert period of the apparatus), a sphygmomanometer. The cuff of the manometer is superimposed on the left shoulder and is not subsequently removed until the end of the study. Blood pressure indicators are recorded as a fraction, where the numerator is the data of the maximum, and the denominator is the data of the minimum pressure.
This method of measuring blood pressure is the most common and is called the auditory or auscultatory method of N.S. Korotkov.
The normal range of fluctuations for the maximum pressure in athletes is 90-139, and for the minimum - 60-89 mm Hg.
BP depends on the age of the person. So, in 17-18-year-old untrained young men, the upper limit of the norm is 129/79 mm Hg, in persons 19-39 years old - 134/84, in persons 40-49 years old - 139/84, in persons 50- 59 years old - 144/89, in persons over 60 years old - 149/89 mm Hg.
Blood pressure below 90/60 mm Hg. called low, or hypotension, blood pressure above 139/89 - high, or hypertension.
Mean blood pressure is the most important indicator of the state of the circulatory system. This value expresses the energy of the continuous movement of blood and, unlike the values of systolic and diastolic pressures, is stable and is held with great constancy.
Determining the level of mean arterial pressure is necessary for calculating peripheral resistance and the work of the heart. At rest, it can be determined by calculation (Savitsky N.N., 1974). Using the Hickarm formula, you can determine the mean arterial pressure:
BPav = BPd - (BPs - BPd)/3, where BPav - mean arterial pressure; BPs - systolic, or maximum, blood pressure; ADd - diastolic, or minimum, blood pressure.
Knowing the values of the maximum and minimum blood pressure, you can determine the pulse pressure (PP):
PD \u003d ADs - ADd.
In sports medicine, the Starr formula (1964) is used to determine stroke or systolic blood volume:
SD = 90.97 + (0.54 x PD) - (0.57 x DC) - 0.61 x V), where SD is the systolic blood volume; PD - pulse pressure; Dd - diastolic pressure; B - age.
Using the values of heart rate and CO, the minute volume of blood circulation (MOC) is determined:
IOC \u003d heart rate x CO l / min.
According to the values of the IOC and ADav, you can determine the total peripheral vascular resistance:
OPSS \u003d ADav x 1332 / MOKdin x cm - 5 / s, where OPSS is the total peripheral vascular resistance; APav - mean arterial pressure; IOC - minute volume of blood circulation; 1332 - coefficient for converting to dynes.
To calculate the specific peripheral vascular resistance (SPVR), one should bring the value of the OPVR to the body surface unit (S), which is calculated according to the Dubois formula, based on the height and body weight of the subject.
S \u003d 167.2 x Mx D x 10 -4 x (m2), where M is body weight, in kilograms; D - body length, in centimeters.
For athletes, the value of peripheral vascular resistance at rest is approximately 1500 dyn cm -5 / s and can vary widely, which is associated with the type of blood circulation and the direction of the training process.
For the maximum possible individualization of the main hemodynamic parameters, which are CO and IOC, it is necessary to bring them to the body surface area. CO index reduced to body surface area (m 2 ), is called the shock index (UI), the IOC indicator is called the cardiac index (CI).
N.N. Savitsky (1976) singled out 3 types of blood circulation according to the SI value: hypo-, -eu- and hyperkinetic types of blood circulation. This index is currently regarded as the main one in the characteristics of blood circulation.
hypokinetic the type of blood circulation is characterized by a low index of SI and relatively high rates of OPSS and UPSS.
At hyperkinetic the type of blood circulation determines the highest values of SI, UI, IOC and SV and low - OPSS and UPSS.
With the average values of all these indicators, the type of blood circulation is called eukinetic.
For the eukinetic type of circulation (ETC) SI = 2.75 - 3.5 l / min / m2. The hypokinetic type of blood circulation (HTC) has SI less than 2.75 l/min/m2, and the hyperkinetic type of blood circulation (HTC) is more than 3.5 l/min/m2.
Different types of blood circulation have a peculiarity of adaptive capabilities and they are characterized by a different course of pathological processes. So, in HrTK, the heart works in the least economical mode and the range of compensatory possibilities of this type of blood circulation is limited. With this type of hemodynamics, there is a high activity of the sympathoadrenal system. On the contrary, with HTC, the cardiovascular system has a large dynamic range and the activity of the heart is most economical.
Since the ways of adaptation of the cardiovascular system in athletes depend on the type of blood circulation, the ability to adapt to training with different directions of the training process has differences with different types of blood circulation.
So, with the predominant development of endurance, HTC occurs in 1/3 of athletes, and with the development of strength and dexterity - only 6%, with the development of speed of this type of blood circulation is not detected. HrTK is noted mainly in athletes whose training is dominated by the development of speed. This type of blood circulation in athletes developing endurance is very rare, mainly with a decrease in the adaptive capabilities of the cardiovascular system.
The level of the functional state of the body can be determined using functional tests and tests.
functional test- a method for determining the degree of influence on the body of dosed physical activity. The test is important for assessing the functional state of the body systems, the degree of adaptability of the body to physical activity to determine their optimal volume and intensity, as well as to identify deviations associated with a violation of the methodology of the training process.
Examination of the cardiovascular system and assessment of physical performance.
Circulation- one of the most important physiological processes that maintain homeostasis, ensure the continuous delivery of nutrients and oxygen necessary for life to all organs and cells of the body, the removal of carbon dioxide and other metabolic products, the processes of immunological protection and humoral (liquid) regulation of physiological functions. The level of the functional state of the cardiovascular system can be assessed using various functional tests.
Single test. Before performing a one-stage test, they rest while standing, without moving for 3 minutes. Then measure the heart rate for one minute. Then 20 deep squats are performed in 30 seconds from the initial position of the legs shoulder-width apart, arms along the body. When squatting, the arms are brought forward, and when straightened, they are returned to their original position. After performing squats, the heart rate is calculated for one minute.
When assessing, the magnitude of the increase in heart rate after exercise is determined in percent. A value of up to 20% means an excellent response of the cardiovascular system to the load, from 21 to 40 % - good; from 41 to 65% - satisfactory; from 66 to 75% - bad; from 76 and more - very bad.
Ruffier index. To assess the activity of the cardiovascular system, you can use the Ryuffier test. After a 5-minute calm state in a sitting position, count the pulse for 10 seconds (P1), then perform 30 squats within 45 seconds. Immediately after squats, count the pulse for the first 10 s (P2) and one minute (P3) after the load. The results are evaluated by the index, which is determined by the formula:
Ruffier index = 6х(Р1+Р2+РЗ)-200
Assessment of cardiac performance: Ruffier index
0 - athletic heart
0.1-5 - "excellent" (very good heart)
5.1 - 10 - "good" (good heart)
10.1 - 15 - "satisfactory" (heart failure) 15.1 - 20 - "poor" (severe heart failure) The test is not recommended for people with diseases of the cardiovascular system.
Research and evaluation of the functional state of the nervous system.
Central nervous system (CNS)- the most complex of all human functional systems.
There are sensitive centers in the brain that analyze changes that occur both in the external and internal environment. The brain controls all bodily functions, including muscle contractions and the secretory activity of the endocrine glands.
The main function of the nervous system is the rapid and accurate transmission of information.
The mental state of a person can be judged by the results of a study of the central nervous system and analyzers.
You can check the state of the central nervous system using orthostaticsamples, reflecting the excitability of the nervous system. The pulse is counted in the prone position after 5-10 minutes of rest, then you need to get up and measure the pulse in the standing position. The state of the central nervous system is determined by the difference in pulse in the supine and standing position for 1 minute. CNS excitability: weak - 0-6, normal - 7-12, live 13-18, increased 19-24 bpm.
An idea of the function of the nervous autonomic system can be obtained from cutaneous response. It is determined as follows: several strips are drawn over the skin with some non-sharp object (the rough end of the pencil) with light pressure. If a pink color appears on the skin at the site of pressure, the skin-vascular reaction is normal, white - the excitability of the sympathetic innervation of the skin vessels is increased, the red or convex-red excitability of the sympathetic innervation of the skin vessels is high. White or red demographer can be observed with deviations in the activity of the autonomic nervous system (with overwork, during illness, with incomplete recovery).
Romberg test reveals imbalance in the standing position. Maintaining normal coordination of movements occurs due to the joint activity of several departments of the central nervous system. These include the cerebellum, the vestibular apparatus, conductors of deep muscle sensitivity, the cortex of the frontal and temporal regions. The central organ for coordinating movements is the cerebellum. The Romberg test is carried out in four modes with a gradual decrease in the area of support. In all cases, the subject's hands are raised forward, fingers are spread apart and eyes are closed. “Very good” if in each position the athlete maintains balance for 15 seconds and there is no staggering of the body, trembling of the hands or eyelids (tremor). Tremor is rated as "satisfactory".
If the balance is disturbed within 15 s, then the sample is evaluated as “unsatisfactory”. This test is of practical importance in acrobatics, gymnastics, trampolining, figure skating and other sports where coordination is essential. Regular training helps to improve coordination of movements. In a number of sports (acrobatics, gymnastics, diving, figure skating, etc.), this method is an informative indicator in assessing the functional state of the central nervous system and the neuromuscular apparatus. With overwork, head trauma and other conditions, these indicators change significantly.
Yarotsky test allows you to determine the sensitivity threshold of the vestibular analyzer. The test is performed in the initial standing position with closed eyes, while the subject, on command, begins rotational head movements at a fast pace. The time of head rotation until the subject loses balance is recorded. In healthy individuals, the time to maintain balance is on average 28 s, in trained athletes - 90 s or more. The threshold level of sensitivity of the vestibular analyzer mainly depends on heredity, but under the influence of training it can be increased.
Finger-nasal test. The subject is invited to touch the tip of the nose with the index finger with open, and then with closed eyes. Normally, there is a hit, touching the tip of the nose. With brain injuries, neurosis (overwork, overtraining) and other functional conditions, a miss (miss), trembling (tremor) of the index finger or hand is noted.
Introduction 4
The dynamometer measures the maximum force of the hand. The partner takes the readings. Then, under the control of vision, the subject compresses the dynamometer 3-4 times with a force corresponding to half of the maximum result. Next, the subject tries to reproduce this effort, but without looking at the device. Following this, under the control of vision, the dynamometer is compressed with a force corresponding to three quarters of the maximum. Again, an attempt is made to reproduce this effort, without looking at the readings of the device. The degree of deviation of the performed effort from the control is a measure of kinesthetic sensitivity. This score is expressed as a percentage of the control force. A difference of 20% indicates a normal state of kinesthetic sensitivity. For example, half the maximum force is 20 kg. This means that the results of the control measurement, which will fit in the range of 20 ± 4 kg, will be normal.
3.2. Studies of the motor analyzer by determining the differential thresholds of its proprioceptive sensitivity
The study requires a goniometer.
The subject is offered in a standing position to move his arm to 90 ° and bend it at the elbow joint under the control of vision at the angle specified by the goniometer. After acquiring the skill of bending to a given angle (after 2-3 attempts), the subject tries to reproduce it by closing his eyes. The accuracy of bending at a small angle (up to 45 °), at an average angle (up to 90 °) and at an angle greater than 90 ° is determined
The normal level of the differential threshold of proprioceptive sensitivity corresponds to the reproduction of flexion with an accuracy of at least ± 10%. For example, when asked to bend the arm to 30°, the normal level of the differential threshold would be flexion through an angle equal to 30±3° (from 27° to 33°).
3.3. Romberg test
Static coordination is the body's ability to maintain balance in simple and complicated postures.
Easy pose. The subject stands without shoes, his feet are tightly pushed together, his arms are stretched forward, his fingers are relaxed, his eyes are closed.
Complicated poses:
1) the subject's legs are on the same line (the heel of one rests on the toe of the other). The position of the hands and eyes is the same;
2) standing on one leg, resting the sole of the other leg on the supporting knee. Hands and eyes - similar to the first pose;
3) pose "swallows". Standing on one leg, the other is raised back, arms to the sides, eyes closed.
The duration of steady standing in the Romberg position, the presence or absence of trembling of the eyelids, hands, swaying of the torso are taken into account.
Steady standing, no trembling of hands and eyelids for 15 seconds is considered normal. and more. Hold the pose for 15 seconds. with slight swaying and tremor - a satisfactory response; unsatisfactory - loss of balance earlier than 15 seconds, strong trembling of hands, eyelids.
3.4. Yarotsky's test
Yarotsky's test allows you to determine the state of the vestibular analyzer.
With systematic sports training, the function of the vestibular analyzer is improved. This is manifested by an increase in resistance to the action of a stimulus adequate for a given analyzer, a decrease in vegetative reflexes. Overtraining, overwork negatively affect the state of the vestibular analyzer.
The Yarotsky test is based on determining the time during which the subject is able to maintain balance when the vestibular apparatus is stimulated by continuous rotation of the head.
Research methodology.
The subject is offered in a standing position to make circular movements of the head and in one direction (the pace is 2 turns in 1 sec.). The duration of maintaining balance is determined by the stopwatch. To prevent a fall, which can lead to injury, it is necessary to stand close to the subject, securing him.
Individual fluctuations in the stability retention time during the Yarotsky test are quite large. The normal state of the vestibular apparatus corresponds to maintaining balance for 28 seconds. In trained athletes, it can reach 90 seconds. and more.
3.5. Clino-orthostatic test of Danielopolu-Prevel
Methods for determining the state of the autonomic system are based on the fact that its divisions, sympathetic and parasympathetic, affect the function of individual organs in different ways, in particular the heart. As a functional load on the body, causing a change in the activation of one of the divisions of the autonomic system and, consequently, the heart rate, is a change in the position of the body in space. The mechanism of the influence of body position on the excitation of one or another part of the autonomic nervous system and, accordingly, on the frequency of heart contractions is not yet fully understood.
The study requires a stopwatch.
Research methodology
In a standing position (orthostatics), the pulse rate is determined for 1 min. Then the subject lies on his back (clinostatics), and the pulse is immediately counted again for the first 15 seconds. in the supine position. Then the subject gets up, and his pulse rate is determined for the first 15 seconds.
With normal activation of the parasympathetic division of the autonomic nervous system, the transition from orthostatic to clinostatic is accompanied by a decrease in the pulse by 4-12 beats (in terms of 1 min.). A pulse slower than 12 beats indicates increased vagal activation. When moving from a horizontal to a vertical position, the normal pulse increases by 6-18 beats per 1 minute. An increase in heart rate by more than 18 beats indicates an increase in the activation of the sympathetic division of the autonomic nervous system. Well-trained athletes, especially those who exercise endurance, are characterized by a predominance of the vagus nerve tone (parasympathetic division), which manifests itself in a decrease in heart rate, i.e., bradycardia, at rest and corresponding shifts in the results of the Danielopoulo-Prevel clino-orthostatic test.
The conclusion about the functional state of the nervous and neuromuscular systems is based on:
1) history data, allowing to specify and more deeply evaluate the data obtained during various tests;
2) analysis of the assessments of all the tests carried out.
The final assessment of the functional state of the nervous and neuromuscular systems is formulated as follows: "The functional state of the nervous and neuromuscular systems is satisfactory (unsatisfactory, good)".
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Circulation- one of the most important physiological processes that maintain homeostasis, ensure the continuous delivery of nutrients and oxygen necessary for their life to all organs and cells of the body, the removal of carbon dioxide and other metabolic products, the processes of immunological protection and humoral regulation of physiological functions (see Fig. ).
A: 1 - internal jugular vein, 2 - left subclavian artery, 3 - pulmonary artery, 4 - aortic arch, 5 - superior vena cava, 6 - heart, 7 - splenic artery, 8 - hepatic artery, 9 - descending aorta, 10 - renal artery, 11 - inferior vena cava, 12 - inferior mesenteric artery, 13 - radial artery, 14 - femoral artery, 15 - capillary network (a - arterial, c - venous, l - lymphatic), 16 - ulnar vein and artery, 17 - superficial palmar arch, 18 - femoral vein, 19 - popliteal artery, 20 - arteries and veins of the lower leg, 21 - dorsal metatarsal vessels, 22 - brachial artery, 23 - brachial vein; B - section of arteries and veins (a - arteries, c - veins); B - valves of the vein of the limb.
Heart rate (HR) depends on many factors, including age, gender, environmental conditions, functional state, body position (see Table Hemodynamics at rest and during exercise). Heart rate is higher in the vertical position of the body compared to the horizontal, decreases with age, is subject to daily fluctuations (biorhythms). During sleep, it decreases by 3-7 or more beats, after eating it increases, especially if the food is rich in proteins, which is associated with an increase in blood flow to the abdominal organs. Ambient temperature also has an effect on heart rate, which increases linearly with it.
Hemodynamics at rest and during exercise depending on body position
| Indicators | At rest | ||||
| lying on your back | standing | lying on your back | standing | standing | |
Minute volume of the heart, l/min |
5,6 | 5,1 | 19,0 | 17,0 | 26,0 |
Stroke volume of the heart, ml |
30 | 80 | 164 | 151 | 145 |
Heart rate, beats/min |
60 | 65 | 116 | 113 | 185 |
Systolic blood pressure, mm Hg Art. |
120 | 130 | 165 | 175 | 215 |
Pulmonary systolic blood pressure, mm Hg Art. |
20 | 13 | 36 | 33 | 50 |
Arteriovenous oxygen difference, ml/l |
70 | 64 | 92 | 92 | 150 |
Total peripheral resistance, dyne/s/cm -5 |
1490 | 1270 | 485 | 555 | 415 |
Left ventricular work, kg/min |
6,3 | 7,8 | 29,7 | 27,3 | 47,7 |
O 2 consumption, ml/min |
250 | 280 | 1750 | 1850 | 3200 |
Hematocrit |
44 | 44 | 48 | 48 | 52 |
In athletes, resting heart rate is lower than in untrained people and is 50-55 beats per minute. In extra-class athletes (cross-country skiers, cyclists, marathon runners, etc.), the heart rate is 30-35 beats / min. Physical activity leads to an increase in heart rate, which is necessary to ensure an increase in cardiac output, and there are a number of patterns that make it possible to use this indicator as one of the most important in carrying out stress tests.
There is a linear relationship between heart rate and work intensity within 50-90% of tolerance to maximum loads (see Fig. ), however, there are individual differences associated with gender, age, physical fitness of the subject, environmental conditions, etc.
I - light load; II - medium; III - heavy load (according to L. Brouda, 1960)
With light physical activity, the heart rate first increases significantly, then gradually decreases to a level that persists throughout the entire period of stable work. With more intense and prolonged loads, there is a tendency to increase heart rate, and at maximum work it increases to the maximum achievable. This value depends on fitness, age, sex of the subject and other factors. At the age of 20, the maximum heart rate is about 200 beats / min, by the age of 64 it drops to about 160 beats / min due to the general age-related decline in human biological functions. Heart rate increases in proportion to the amount of muscle work. Usually, at a load level of 1000 kg / min, the heart rate reaches 160-170 beats / min, as the load further increases, heart contractions accelerate more moderately, and gradually reach a maximum value of 170-200 beats / min. Further increase in load is no longer accompanied by an increase in heart rate.
It should be noted that the work of the heart at a very high rate of contractions becomes less efficient, since the time for filling the ventricles with blood is significantly reduced and the stroke volume decreases.
Tests with increasing loads until the maximum heart rate is reached lead to exhaustion, and in practice are used only in sports and space medicine.
According to the WHO recommendation, loads are considered acceptable if the heart rate reaches 170 beats / min and usually stops at this level when determining exercise tolerance and the functional state of the cardiovascular and respiratory systems.
Blood (arterial) pressure
The liquid flowing through the vessel exerts pressure on its wall, usually measured in millimeters of mercury (torr) and less often in dynes/cm. Pressure equal to 110 mm Hg. Art., means that if the vessel were connected to a mercury manometer, the pressure of the liquid at the end of the vessel would shift the column of mercury to a height of 110 mm. With a water pressure gauge, the bar travel would be about 13 times greater. Pressure in 1 mm Hg. Art. - 1330 dynes/cm2. Pressure and blood flow in the lungs change depending on the position of the human body.
There is a pressure gradient directed from arteries to arterioles and capillaries and from peripheral to central veins (see Fig. ). Thus, blood pressure decreases in the following direction: aorta - arterioles - capillaries - venules - large veins - vena cava. Due to this gradient, blood flows from the heart to arterioles, then to capillaries, venules, veins and back to the heart. The maximum pressure reached when blood is ejected from the heart into the aorta is called systolic (BP). When the aortic valves close after pushing blood out of the heart, the pressure drops to a value corresponding to the so-called diastolic pressure (DP). The difference between systolic and diastolic pressure is called pulse pressure. Mean pressure (Mp. D) can be determined by measuring the area bounded by the pressure curve and dividing it by the length of that curve.
At rest (I), with expansion (II) and narrowing (III) of the vessels. In large veins located near the heart (vena cava), the pressure during inspiration may be slightly lower than atmospheric pressure (C.A. Keele, E. Neil, 1971)
Wed D = (area under the curve) / (length of the curve)
Fluctuations in blood pressure are due to the pulsating nature of blood flow and the high elasticity and extensibility of blood vessels. Unlike fluctuating systolic and diastolic pressures, mean pressure is relatively constant. In most cases, it can be considered equal to the sum of diastolic and 1/3 pulse (B. Folkov, E. Neal, 1976):
Pcp. = P diast. + [(P system - P diast.) / 3]
The speed of propagation of the pulse wave depends on the size and elasticity of the vessel. In the aorta, it is 3-5 m/s, in the middle arteries (subclavian and femoral) - 7-9 m/s, in the small arteries of the limbs - 15-40 m/s.
The level of blood pressure depends on a number of factors: the amount and viscosity of blood entering the vascular system per unit time, the capacity of the vascular system, the intensity of outflow through the precapillary bed, the tension of the walls of arterial vessels, physical activity, the environment, etc. others
In the study of blood pressure, it is of interest to measure the following indicators: minimum arterial pressure, average dynamic, maximum shock and pulse.
Under the minimum or diastolic pressure understand the smallest value that reaches the blood pressure at the end of the diastolic period.
Minimum pressure depends on the degree of patency or the amount of blood outflow through the system of precapillaries, heart rate and elastic-viscous properties of arterial vessels.
Average dynamic pressure- this is the average pressure value that would be able, in the absence of pulse pressure fluctuations, to give the same hemodynamic effect as observed with natural, fluctuating blood pressure, that is, the average pressure expresses the energy of the continuous movement of blood. The average dynamic pressure is determined by the following formulas:
1. Hickam formula:
P m \u003d A / 3 + P d
where P m is the average dynamic arterial pressure (mm Hg); A - pulse pressure (mm Hg); P d - minimum or diastolic blood pressure (mm Hg)
2. Formula of Wetzler and Roger:
P m \u003d 0.42Р s + 0.58Р d
where P s - systolic, or maximum pressure, P d - diastolic, or minimum, blood pressure (mm Hg).
3. The formula is quite common:
P m \u003d 0.42A + P d
where A is pulse pressure; P d - diastolic pressure (mm Hg).
Maximum, or systolic pressure- a value that reflects the entire supply of potential and kinetic energy that a moving mass of blood has in a given section of the vascular system. The maximum pressure is the sum of the lateral systolic pressure and shock (hemodynamic shock). Lateral systolic pressure acts on the lateral wall of the artery during ventricular systole. A hemodynamic shock is created when an obstacle suddenly appears in front of the blood flow moving in the vessel, while the kinetic energy for a short moment turns into pressure. Hemodynamic shock is the result of inertial forces, defined as the increase in pressure with each pulsation when the vessel is compressed. The magnitude of the hemodynamic impact in healthy people is 10-20 mm. rt. Art.
True pulse pressure is the difference between lateral and minimum arterial pressure.
To measure blood pressure, a Riva-Rocci sphygmomanometer and a phonendoscope are used.
On fig. the values of arterial pressure in healthy people aged 15 to 60 years and older are given. With age, in men, systolic and diastolic pressures grow evenly, while in women, the dependence of pressure on age is more complicated: from 20 to 40 years, their pressure increases slightly, and its value is less than in men; after the age of 40, with the onset of menopause, pressure indicators increase rapidly and become higher than in men.
Systolic and diastolic blood pressure according to age and gender
Obese people have higher blood pressure than normal weight people.
During exercise, systolic and diastolic blood pressure, cardiac output and heart rate increase, as well as when walking at a moderate pace, blood pressure increases.
When smoking, systolic pressure can increase by 10-20 mm Hg. Art. At rest and during sleep, blood pressure decreases significantly, especially if it was elevated.
Blood pressure rises in athletes before the start, sometimes even a few days before the competition.
Blood pressure is mainly influenced by three factors: a) heart rate (HR); b) changes in peripheral vascular resistance; and c) changes in stroke volume or cardiac output.
Electrocardiography (ECG)
In the human heart there is a specialized, anatomically separate conducting system. It consists of the sinoatrial and atrioventricular nodes, the bundles of His with his left and right legs, and Purkyne fibers. This system is formed by specialized muscle cells that have the property of automatism and a high rate of excitation transmission.
The propagation of an electrical impulse (action potential) along the conduction system and muscle of the atria and ventricles is accompanied by depolarization and repolarization. The resulting waves, or waves, are called depolarization (QRS) and repolarization (T) waves of the ventricles.
EKG- this is a record of the electrical activity (depolarization and repolarization) of the heart, recorded using an electrocardiograph, the electrodes of which (leads) are placed not directly on the heart, but on different parts of the body (see Fig. ).
Scheme of applying electrodes for standard (a) and chest (b) leads of the electrocardiogram and ECG obtained with these leads
The electrodes can be located at different distances from the heart, including on the limbs and chest (they are denoted by the symbol V).
Standard leads from the extremities: the first (I) lead (right hand - PR, left hand - LR); the second (II) lead (PR and left leg - LN) and the third (III) lead (LR-LN) (see Fig. ).
Breast leads. To take an ECG, an active electrode is applied to various points of the chest (see Fig. ), denoted by numbers (V 1, V 2, V 3, V 4, V 5, V 6). These leads reflect electrical processes in more or less localized areas and help to identify a number of heart diseases.
Waves and intervals of the electrocardiogram(ECG) In fig. shows a typical normal human ECG in one of the standard leads, the duration and amplitude of the teeth are given in table. Human normal electrocardiogram (ECG) waveforms. The P wave corresponds to atrial depolarization, the QRS complex to the beginning of ventricular depolarization, and the T wave to ventricular repolarization. The U wave is usually absent.
pp - excitation of the right atrium; lp - excitation of the left atrium
Human normal electrocardiogram (ECG) waveforms
| Tooth designations | Teeth characteristic | Duration range, s | Amplitude range in leads I, II and III, mm |
| P | Reflects depolarization (excitation) of both atria, normally the wave is positive |
0,07-0,11 | 0,5-2,0 |
| Q | Reflects the onset of ventricular depolarization, negative wave (downward) |
0,03 | 0,36-0,61 |
| R | Main wave of ventricular depolarization, positive (upward) |
see QRS | 5,5-11,5 |
| S | Reflects the end of depolarization of both ventricles, negative wave |
- | 1,5-1,7 |
| QRS | The set of teeth (Q, R, S), reflecting the depolarization of the ventricles |
0,06-0,10 | 0-3 |
| T | Reflects repolarization (fading) of both ventricles; the wave is positive in I, II, III, aVL, aVF and negative in aVR |
0,12-0,28 | 1,2-3,0 |
When analyzing ECG, the time intervals between some teeth are of great importance (see table. Electrocardiogram intervals). The deviation of the duration of these intervals beyond the normal range may indicate a violation of the function of the heart.
Electrocardiogram intervals
| Interval designation | Interval characteristics | Duration, s |
| P-Q | From the start of atrial excitation (P) to the start of ventricular excitation (Q) |
0,12-0,20 |
| P-R | From the beginning of R to the beginning of R |
0,18-0,20 |
| Q-T (QRST) | From the beginning of Q to the end of T; corresponds to depolarization and repolarization of the ventricles (electrical systole) |
0,38-0,55 |
| S-T | From the end of S to the beginning of T, reflects the phase of complete depolarization of the ventricles. Normally, its deviation (displacement) from the isoline should not exceed 1 mm |
0-0,15 |
| R-R | Duration of the cardiac cycle (full cycle of the heart). Normally, these segments have almost the same duration. |
|
| T-P | Reflects the resting state of the myocardium (electrical diastole). This segment should be taken as the level of the isoelectric line in normal and pathological conditions. |
Pathological ECG changes
There are two main types of ECG pathological changes: the first includes rhythm disturbances and the occurrence of excitation, the second - disturbances in the conduction of excitation and distortion of the shape and configuration of the teeth.
Arrhythmias, or heart rhythm disturbances, are characterized by an irregular supply of impulses from the sinoatrial (SA) node.
The rhythm (frequency of contractions) of the heart may be low (bradycardia) or very high (tachycardia) (see Fig. ). Atrial extrasystoles are characterized by a shortened PP interval followed by a long PP interval (see Fig. , BUT). With ventricular extrasystoles, when excitation occurs in an ectopic focus localized in the wall of the ventricle, premature contraction is characterized by a distorted QRS complex (see Fig. , AT). Ventricular tachycardia is accompanied by rapid regular discharges of an ectopic focus located in the ventricle (see Fig. , D). Atrial or ventricular fibrillation is characterized by irregular, arrhythmic contractions that are hemodynamically ineffective. Atrial fibrillation is manifested by irregular arrhythmic contractions, in which the frequency of atrial contractions is 2-5 times higher than that of the ventricles (see Fig. , E). In this case, for each R wave there are 1, 2 or 3 irregular P waves.
With atrial flutter, more regular and less frequent atrial complexes are observed, the frequency of which is still 2-3 times higher than the frequency of ventricular contraction (see Fig. , AND). Atrial fibrillation can be caused by multiple ectopic foci in their wall, while discharges of a single ectopic focus are accompanied by atrial flutter.
ECG in cardiac arrhythmia: A - atrial extrasystole; B - nodal extrasystole; B - ventricular extrasystole; G - atrial tachycardia; D - ventricular tachycardia; E - atrial fibrillation; F - atrial flutter
Conduction disorders
Ischemic heart disease, myocarditis, coronary cardiosclerosis and other diseases occur as a result of impaired blood supply to the myocardium.
On fig. shows changes in the QRS complex in myocardial infarction. In the acute stage, pronounced changes in the Q and T waves and the ST segment are observed. Of particular note is the ST segment elevation and inverted T wave in some leads. First of all, myocardial ischemia occurs (violation of its blood supply, pain attack), tissue damage, followed by the formation of necrosis (necrosis) of the myocardium. Circulatory disorders in the heart muscle are accompanied by conduction changes, arrhythmias.
ECG changes in dynamics in violation of coronary circulation (myocardial infarction). With a fresh heart attack, a pathological Q wave, a negative T wave, and an upward displacement of the ST segment are observed in a number of leads. After a few weeks, the ECG is almost back to normal.
In sports medicine, ECG is recorded directly during a dosed physical activity.
For a complete characterization of the electrical activity of the heart at all stages of the load, ECG is recorded during the first minute of work, and then in the middle and at the end (when tested on a treadmill, bicycle ergometer or Harvard step test, hydrochannel, etc.).
Athletes are characterized by the following features of ECG:
sinus bradycardia,
Smoothed P wave (in cyclic sports),
An increase in the voltage of the QRS complex (associated with hypertrophy of the left ventricle of the heart) (see Fig. Electrocardiogram in left ventricular hypertrophy),
Incomplete blockade of the right leg of Giss (slow conduction).
Electrocardiogram in left ventricular hypertrophy
Electrocardiogram with left ventricular hypertrophy: QRS = 0.09 s; wave Q I, V4-V6 is not defined; R I high; > R II > r III< S III (< a = -5°); S V1-V3 глубокий, переходная зона смещена влево; R V5,V6 высокий, R V6 >R V5 ; S V1-V3 + R V6 > 35 mm; PS-T I, II, aVL, V5, V6 below the isoline; T I,aVL,V6 negative; T V1,aVR positive
In well-trained athletes, during moderate exercise, the P, R, and T waves usually increase, and the PQ, QRS, and QRST segments shorten.
If the loads exceed the degree of preparedness of the athlete, circulatory disorders and adverse biochemical changes occur in the heart muscle, which manifest themselves in the ECG as rhythm or conduction disturbances and depression of the ST segment. The causes of heart damage are hypoxemia and tissue hypoxia, spasm of the coronary vessels and atherosclerosis.
Athletes have myocardial dystrophy, acute heart failure, hemorrhage into the heart muscle, metabolic necrosis in the myocardium. With dystrophy, flattening of the T and P waves is noted on the ECG, the P-Q and Q-T intervals are lengthened. When the right ventricle is overstrained on the ECG in V1.2 leads, an incomplete or complete blockade of the right branch of the Hiss bundle appears, the amplitude of the R wave increases, the S wave decreases, a negative T wave appears and the ST segment shifts below the isoline, extrasystole (prolongation of the PQ interval).
English
assessment of cardiovascular function– score function of the cardiovascular system
blood circulation
arterial
blood (blood) pressure - blood (blood) pressure
electrocardiography (ECG) - electrocardiography (ECG)
pathological changes in ECG
conduction disorders
Ministry of Sports of the Russian Federation
Bashkir Institute of Physical Culture (branch) UralGUFK
Faculty of Sports and Adaptive Physical Education
Department of Physiology and Sports Medicine
Course work
by discipline adaptation to physical activity of persons with disabilities in health status
FUNCTIONAL STATE OF THE CARDIOVASCULAR SYSTEM IN ADOLESCENTS
Performed by a student of the AFC 303 group
Kharisova Evgenia Radikovna,
specialization "Physical rehabilitation"
Scientific adviser:
cand. biol. Sciences, Associate Professor E.P. Salnikova
INTRODUCTION
1. LITERATURE REVIEW
1 Morphofunctional features of the cardiovascular system
2 Characteristics of the influence of hypodynamia and physical activity on the cardiovascular system
3 Methods for assessing the fitness of the cardiovascular system using tests
OWN RESEARCH
2 Research results
REFERENCES
APPS
INTRODUCTION
Relevance. Diseases of the cardiovascular system are currently the main cause of death and disability in the population of economically developed countries. Every year the frequency and severity of these diseases are steadily increasing, more and more diseases of the heart and blood vessels occur at a young, creatively active age.
Recently, the state of the cardiovascular system makes you seriously think about your health, your future.
Scientists from the University of Lausanne have prepared for the World Health Organization a report on the statistics of cardiovascular disease in 34 countries since 1972. Russia took first place in mortality from these ailments, ahead of the former leader - Romania.
Statistics for Russia looks simply fantastic: out of 100,000 people, only 330 men and 154 women die from myocardial infarction in Russia every year, and 204 men and 151 women die from strokes. Among the total mortality in Russia, cardiovascular diseases account for 57%. There is no other developed country in the world with such a high rate! Every year, 1 million 300 thousand people die from cardiovascular diseases in Russia - the population of a large regional center.
Social and medical measures do not give the expected effect in maintaining people's health. In the improvement of society, medicine went mainly along the path "from illness to health." Social activities are aimed primarily at improving the environment and consumer goods, but not at educating a person.
The most justified way to increase the adaptive capacity of the body, maintain health, prepare the individual for fruitful labor, socially important activities - physical education and sports.
One of the factors influencing this system of the body is physical activity. Identification of the dependence of the health of the human cardiovascular system and physical activity will be the basis for this course work.
The object of research is the functional state of the cardiovascular system.
The subject of the study is the functional state of the cardiovascular system in adolescents.
The aim of the work is to analyze the influence of physical activity on the functional state of the cardiovascular system.
-to study the influence of motor activity on the cardiovascular system;
-to study methods for assessing the functional state of the cardiovascular system;
-to study changes in the state of the cardiovascular system during physical exertion.
CHAPTER 1. THE CONCEPT OF MOTOR ACTIVITY AND ITS ROLE FOR HUMAN HEALTH
1Morphofunctional features of the cardiovascular system
Cardiovascular system - a set of hollow organs and vessels that provide the process of blood circulation, constant, rhythmic transportation of oxygen and nutrients in the blood and excretion of metabolic products. The system includes the heart, aorta, arterial and venous vessels.
The heart is the central organ of the cardiovascular system that performs a pumping function. The heart provides us with the energy to move, to speak, to express emotions. The heart beats rhythmically with a frequency of 65-75 beats per minute, on average - 72. At rest for 1 minute. the heart pumps about 6 liters of blood, and during hard physical work this volume reaches 40 liters or more.
The heart is surrounded by a connective tissue membrane - the pericardium. There are two types of valves in the heart: atrioventricular (separating the atria from the ventricles) and semilunar (between the ventricles and large vessels - the aorta and pulmonary artery). The main role of the valvular apparatus is to prevent the backflow of blood into the atrium (see Figure 1).
In the chambers of the heart, two circles of blood circulation originate and end.
The large circle begins with the aorta, which departs from the left ventricle. The aorta passes into arteries, arteries into arterioles, arterioles into capillaries, capillaries into venules, venules into veins. All veins of the large circle collect their blood in the vena cava: the upper one - from the upper part of the body, the lower one - from the lower one. Both veins drain into the right.
From the right atrium, blood enters the right ventricle, where the pulmonary circulation begins. Blood from the right ventricle enters the pulmonary trunk, which carries blood to the lungs. The pulmonary arteries branch to the capillaries, then the blood is collected in venules, veins and enters the left atrium, where the pulmonary circulation ends. The main role of the large circle is to ensure the metabolism of the body, the main role of the small circle is to saturate the blood with oxygen.
The main physiological functions of the heart are: excitability, the ability to conduct excitation, contractility, automatism.
Cardiac automatism is understood as the ability of the heart to contract under the influence of impulses arising in itself. This function is performed by atypical cardiac tissue which consists of: sinoauricular node, atrioventricular node, Hiss bundle. A feature of the automatism of the heart is that the overlying area of automatism suppresses the automatism of the underlying one. The leading pacemaker is the sinoauricular node.
A cardiac cycle is understood as one complete contraction of the heart. The cardiac cycle consists of systole (contraction period) and diastole (relaxation period). Atrial systole supplies blood to the ventricles. Then the atria enter the diastole phase, which continues throughout the entire ventricular systole. During diastole, the ventricles fill with blood.
Heart rate is the number of heartbeats in one minute.
Arrhythmia is a violation of the rhythm of heart contractions, tachycardia is an increase in the heart rate (HR), often occurs with an increase in the influence of the sympathetic nervous system, bradycardia is a decrease in heart rate, often occurs with an increase in the influence of the parasympathetic nervous system.
The indicators of cardiac activity include: stroke volume - the amount of blood that is ejected into the vessels with each contraction of the heart.
Minute volume is the amount of blood that the heart pumps into the pulmonary trunk and aorta in a minute. The minute volume of the heart increases with physical activity. With a moderate load, the minute volume of the heart increases both due to an increase in the strength of heart contractions and due to the frequency. With loads of high power only due to an increase in heart rate.
The regulation of cardiac activity is carried out due to neurohumoral influences that change the intensity of heart contractions and adapt its activity to the needs of the body and the conditions of existence. The influence of the nervous system on the activity of the heart is carried out due to the vagus nerve (parasympathetic division of the central nervous system) and due to the sympathetic nerves (sympathetic division of the central nervous system). The endings of these nerves change the automatism of the sinoauricular node, the speed of the conduction of excitation through the conduction system of the heart, and the intensity of heart contractions. The vagus nerve, when excited, reduces the heart rate and the strength of heart contractions, reduces the excitability and tone of the heart muscle, and the speed of excitation. Sympathetic nerves, on the contrary, increase heart rate, increase the strength of heart contractions, increase the excitability and tone of the heart muscle, as well as the speed of excitation.
In the vascular system, there are: main (large elastic arteries), resistive (small arteries, arterioles, precapillary sphincters and postcapillary sphincters, venules), capillaries (exchange vessels), capacitive vessels (veins and venules), shunting vessels.
Blood pressure (BP) refers to the pressure in the walls of blood vessels. The pressure in the arteries fluctuates rhythmically, reaching its highest level during systole and decreasing during diastole. This is explained by the fact that the blood ejected during systole meets the resistance of the walls of the arteries and the mass of blood filling the arterial system, the pressure in the arteries rises and some stretching of their walls occurs. During diastole, blood pressure decreases and is maintained at a certain level due to the elastic contraction of the walls of the arteries and the resistance of the arterioles, due to which the blood continues to move into the arterioles, capillaries and veins. Therefore, the value of blood pressure is proportional to the amount of blood ejected by the heart into the aorta (i.e. stroke volume) and peripheral resistance. There are systolic (SBP), diastolic (DBP), pulse and mean blood pressure.
Systolic blood pressure is the pressure caused by the systole of the left ventricle (100 - 120 mm Hg). Diastolic pressure - is determined by the tone of the resistive vessels during the diastole of the heart (60-80 mm Hg). The difference between SBP and DBP is called pulse pressure. Mean BP equals the sum of DBP and 1/3 of pulse pressure. Average blood pressure expresses the energy of the continuous movement of blood and is constant for a given organism. An increase in blood pressure is called hypertension. A decrease in blood pressure is called hypotension. Normal systolic pressure ranges from 100-140 mm Hg, diastolic pressure 60-90 mm Hg. .
Blood pressure in healthy people is subject to significant physiological fluctuations depending on physical activity, emotional stress, body position, meal times, and other factors. The lowest pressure is in the morning, on an empty stomach, at rest, that is, in those conditions in which the main metabolism is determined, therefore this pressure is called the main or basal. A short-term increase in blood pressure can be observed with great physical exertion, especially in untrained individuals, with mental arousal, drinking alcohol, strong tea, coffee, with excessive smoking and severe pain.
The pulse is called the rhythmic oscillations of the wall of the arteries, due to the contraction of the heart, the release of blood into the arterial system and the change in pressure in it during systole and diastole.
The following properties of the pulse are determined: rhythm, frequency, tension, filling, size and shape. In a healthy person, heart contractions and pulse waves follow each other at regular intervals, i.e. the pulse is rhythmic. Under normal conditions, the pulse rate corresponds to the heart rate and is equal to 60-80 beats per minute. The pulse rate is counted for 1 min. In the supine position, the pulse is on average 10 beats less than standing. In physically developed people, the pulse rate is below 60 beats / min, and in trained athletes up to 40-50 beats / min, which indicates an economical work of the heart.
The pulse of a healthy person at rest is rhythmic, without interruptions, good filling and tension. Such a pulse is considered rhythmic when the number of beats in 10 seconds is noted from the previous count for the same period of time by no more than one beat. For counting, use a stopwatch or an ordinary watch with a second hand. To obtain comparable data, you must always measure the pulse in the same position (lying, sitting or standing). For example, in the morning, measure the pulse immediately after sleeping while lying down. Before and after classes - sitting. When determining the value of the pulse, it should be remembered that the cardiovascular system is very sensitive to various influences (emotional, physical stress, etc.). That is why the most calm pulse is recorded in the morning, immediately after waking up, in a horizontal position.
1.2 Characteristics of the influence of physical inactivity and physical activity on the cardiovascular system
Movement is a natural need of the human body. Excess or lack of movement is the cause of many diseases. It forms the structure and functions of the human body. Physical activity, regular physical culture and sports are a prerequisite for a healthy lifestyle.
In real life, the average citizen does not lie motionless, fixed on the floor: he goes to the store, to work, sometimes even runs after the bus. That is, in his life there is a certain level of physical activity. But it is clearly not enough for the normal functioning of the body. There is a significant debt volume of muscle activity.
Over time, our average citizen begins to notice that something is wrong with his health: shortness of breath, tingling in different places, periodic pain, weakness, lethargy, irritability, and so on. And the further - the worse.
Consider how the lack of physical activity affects the cardiovascular system.
In a normal state, the main part of the load on the cardiovascular system is to ensure the return of venous blood from the lower body to the heart. This is facilitated by:
.pushing blood through the veins during muscle contraction;
.suction action of the chest due to the creation of negative pressure in it during inhalation;
.vein device.
With a chronic lack of muscle work with the cardiovascular system, the following pathological changes occur:
-the effectiveness of the “muscle pump” decreases - as a result of insufficient strength and activity of the skeletal muscles;
-the effectiveness of the "respiratory pump" to ensure venous return is significantly reduced;
-cardiac output decreases (due to a decrease in systolic volume - a weak myocardium can no longer push out as much blood as before);
-the reserve of increase in the stroke volume of the heart is limited when performing physical activity;
-heart rate increases. This is due to the fact that the effect of cardiac output and other factors to ensure venous return has decreased, but the body needs to maintain a vital level of blood circulation;
-despite the increase in heart rate, the time for a complete blood circulation increases;
-as a result of an increase in heart rate, the autonomic balance shifts towards increased activity of the sympathetic nervous system;
-vegetative reflexes from the baroreceptors of the carotid arch and aorta are weakened, which leads to a breakdown in the adequate informativeness of the mechanisms for regulating the proper level of oxygen and carbon dioxide in the blood;
-hemodynamic provision (the required intensity of blood circulation) lags behind the growth of energy demands in the process of physical activity, which leads to an earlier inclusion of anaerobic energy sources, a decrease in the threshold of anaerobic metabolism;
-the amount of circulating blood decreases, i.e., a larger volume of it is deposited (stored in the internal organs);
-the muscular layer of the vessels atrophies, their elasticity decreases;
-myocardial nutrition worsens (ischemic heart disease looms ahead - every tenth dies from it);
-the myocardium atrophies (and why do we need a strong heart muscle if high-intensity work is not required?).
The cardiovascular system is detrained. Its adaptability is reduced. Increases the likelihood of cardiovascular disease.
A decrease in vascular tone as a result of the above reasons, as well as smoking and an increase in cholesterol, leads to arteriosclerosis (hardening of blood vessels), the vessels of the elastic type are most susceptible to it - the aorta, coronary, renal and cerebral arteries. The vascular reactivity of hardened arteries (their ability to contract and expand in response to signals from the hypothalamus) is reduced. Atherosclerotic plaques form on the walls of blood vessels. Increased peripheral vascular resistance. Fibrosis, hyaline degeneration develops in small vessels, which leads to insufficient blood supply to the main organs, especially the myocardium of the heart.
Increased peripheral vascular resistance, as well as a vegetative shift towards sympathetic activity, becomes one of the causes of hypertension (an increase in pressure, mainly arterial). Due to the decrease in the elasticity of the vessels and their expansion, the lower pressure decreases, which causes an increase in pulse pressure (the difference between the lower and upper pressures), which eventually leads to an overload of the heart.
Hardened arterial vessels become less elastic and more fragile, and begin to collapse, thrombi (blood clots) form at the site of ruptures. This leads to thromboembolism - the separation of the clot and its movement in the blood stream. Stopping somewhere in the arterial tree, it often causes serious complications in that it impedes the movement of blood. It often causes sudden death if a clot occludes a vessel in the lungs (pneumoembolism) or in the brain (cerebral vascular incident).
Heart attack, heart pain, spasms, arrhythmia and a number of other cardiac pathologies arise due to one mechanism - coronary vasospasm. At the time of the attack and pain, the cause is a potentially reversible nerve spasm of the coronary artery, which is based on atherosclerosis and ischemia (insufficient oxygen supply) of the myocardium.
It has long been established that people engaged in systematic physical labor and physical education have wider heart vessels. Coronary blood flow in them, if necessary, can be increased to a much greater extent than in physically inactive people. But, most importantly, thanks to the economical work of the heart, trained people expend less blood for the same work for the work of the heart than untrained people.
Under the influence of systematic training, the body develops the ability to very economically and adequately redistribute blood to various organs. Recall the unified energy system of our country. Every minute, the central control panel receives information about the need for electricity in various zones of the country. Computers instantly process incoming information and suggest a solution: increase the amount of energy in one area, leave it at the same level in another, reduce it in a third. The same is true in the body. With increasing muscular work, the bulk of the blood goes to the muscles of the body and to the muscle of the heart. Muscles that do not take part in work during exercise receive much less blood than they received at rest. It also reduces blood flow in the internal organs (kidneys, liver, intestines). Decreased blood flow in the skin. The blood flow does not change only in the brain.
What happens to the cardiovascular system under the influence of long-term physical education? In trained people, myocardial contractility improves significantly, central and peripheral blood circulation increases, efficiency increases, heart rate decreases not only at rest, but also at any load, up to maximum (this condition is called training bradycardia), systolic, or shock, blood volume. Due to the increase in stroke volume, the cardiovascular system of a trained person is much easier than an untrained person to cope with increasing physical exertion, fully providing blood to all the muscles of the body that take part in the load with great tension. A trained person's heart weighs more than an untrained one. The volume of the heart in people engaged in physical labor is also much larger than the volume of the heart of an untrained person. The difference can reach several hundred cubic millimeters (see Figure 2).
As a result of an increase in stroke volume in trained people, the minute volume of blood also increases relatively easily, which is possible due to myocardial hypertrophy caused by systematic training. Sports hypertrophy of the heart is an extremely favorable factor. This increases not only the number of muscle fibers, but also the cross section and mass of each fiber, as well as the volume of the cell nucleus. With hypertrophy, the metabolism in the myocardium improves. With systematic training, the absolute number of capillaries per unit surface of skeletal muscles and heart muscles increases.
Thus, systematic physical training has an extremely beneficial effect on the cardiovascular system of a person and, in general, on his entire body. The effects of physical activity on the cardiovascular system are shown in Table 3.
1.3 Methods for assessing cardiovascular fitness using tests
To assess fitness, the following tests provide important information on the regulation of the cardiovascular system:
orthostatic test.
Count the pulse for 1 minute in bed after sleep, then slowly get up and after 1 minute while standing, count the pulse again. The transition of their horizontal to vertical position is accompanied by a change in hydrostatic conditions. Venous return decreases - as a result, the output of blood from the heart decreases. In this regard, the value of the minute volume of blood at this time is supported by an increase in the heart rate. If the difference in pulse beats is not more than 12, then the load is adequate to your capabilities. An increase in the pulse with this sample up to 18 is considered as a satisfactory reaction.
Squat test.
squats in 30 seconds, recovery time - 3 minutes. Squats are deep from the main stance, raising the arms forward, keeping the torso straight and spreading the knees wide. When analyzing the results obtained, it is necessary to focus on the fact that with a normal reaction of the cardiovascular system (CVS) to the load, the increase in heart rate will be (for 20 squats) + 60-80% of the original. Systolic pressure will increase by 10-20 mmHg. (15-30%), diastolic pressure drops to 4-10 mm Hg. or remain normal.
Recovery of the pulse should come to the original within two minutes, blood pressure (syst. and diast.) by the end of 3 minutes. This test makes it possible to judge the fitness of the body and get an idea of the functional ability of the circulatory system as a whole and its individual links (heart, blood vessels, regulating the nervous apparatus).
CHAPTER 2. OWN RESEARCH
1 Materials and research methods
The activity of the heart is strictly rhythmic. To determine the heart rate, place your hand in the region of the upper part of the heart (5th intercostal space on the left), and you will feel its tremors following at regular intervals. There are several methods for recording the pulse. The simplest of them is palpation, which consists in probing and counting pulse waves. At rest, the pulse can be counted in 10, 15, 30, and 60 second intervals. After exercise, count your pulse in 10-second intervals. This will allow you to set the moment of recovery of the pulse to its original value and to fix the presence of arrhythmia, if any.
As a result of systematic physical exercises, the heart rate decreases. After 6-7 months of training sessions, the pulse decreases by 3-4 bpm, and after a year of training - by 5-8 bpm.
In a state of overwork, the pulse can be either rapid or slow. In this case, arrhythmia often occurs, i.e. shocks are felt at irregular intervals. We will determine the individual training pulse (ITP) and evaluate the activity of the cardiovascular system of 9th grade students.
To do this, we use the Kervonen formula.
from the number 220 you need to subtract your age in years
from the received figure, subtract the number of beats of your pulse per minute at rest
multiply the resulting figure by 0.6 and add to it the value of the pulse at rest
To determine the maximum possible load on the heart, add 12 to the training pulse value. To determine the minimum load, subtract 12 from the ITP value.
Let's do some research in 9th grade. The study involved 11 people, students of the 9th grade. All measurements were taken before the start of classes in the school gym. The children were offered to rest in a lying position on mats for 5 minutes. After that, by palpation on the wrist, the pulse was calculated for 30 seconds. The result obtained was multiplied by 2. After that, according to the Kervonen formula, an individual training pulse - ITP was calculated.
In order to trace the difference in heart rate between the results of trained and untrained students, the class was divided into 3 groups:
.actively involved in sports;
.actively involved in physical education;
.students with deviations in health related to the preparatory health group.
We used the method of questioning and the data of medical indications placed in the class journal on the health sheet. It turned out that 3 people are actively involved in sports, 6 people are engaged only in physical education, 2 people have health deviations and contraindications in performing some physical exercises (preparatory group).
1 Research results
Data with the results of the pulse are presented in tables 1.2 and figure 1, taking into account the physical activity of students.
Table 1 Summary table data heart rate in peace, ETC, estimates performance
Surname of the student Heart rate at rest Khalitova A.8415610. Kurnosov A.7615111. Gerasimova D.80154
Table 2. Pulse readings of 9th grade students by groups
HR at rest in trained HR at rest in students engaged in Physical EducationHR at rest in students with low physical activity or with health problems. 6 pers. - 60 bpm 3 people - 65-70 bpm 2 people - 70-80 bpm. Norm - 60-65 bpm. Norm - 65-72 bpm. Norm - 65-75 bpm.
Rice. 1. Heart rate indicator at rest, ITP (individual training pulse) of 9th grade students
This chart shows that trained students have a much lower resting heart rate than untrained peers. Therefore, the ITP is also lower.
From the test, we see that with little physical activity, the performance of the heart deteriorates. Already by heart rate at rest, we can judge the functional state of the heart, because. the faster the resting heart rate, the higher the individual training heart rate and the longer the recovery period after exercise. A heart adapted to physical stress under conditions of relative physiological rest has moderate bradycardia and works more economically.
The data obtained in the course of the study confirm the fact that only with high physical activity can we speak of a good assessment of the working capacity of the heart.
cardiac vascular hypodynamia pulse
1. Under the influence of physical activity in trained people, myocardial contractility improves significantly, central and peripheral blood circulation increases, efficiency increases, heart rate decreases not only at rest, but also at any load, up to maximum (this state is called training bradycardia), increased systolic, or shock, blood volume. Due to the increase in stroke volume, the cardiovascular system of a trained person is much easier than an untrained person to cope with increasing physical exertion, fully providing blood to all the muscles of the body that take part in the load with great tension.
.Methods for assessing the functional state of the cardiovascular system include:
-orthostatic test;
-squat test;
-Kervonen method and others.
As a result of the studies, it was found that in trained adolescents, the pulse and ITP at rest are lower, that is, they work more economically than among untrained peers.
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APPS
Attachment 1
Figure 2 Structure of the heart
Vascular network of the heart of an untrained person Vascular network of the heart of an athlete Figure 3 Vascular network
Appendix 2
Table 3. Differences in the state of the cardiovascular system of trained and untrained people
Indicators Trained Untrained Anatomical parameters: weight of the heart heart volume capillaries and circumferential vessels of the heart 350-500 g 900-1400 ml large amount 250-300 g 600-800 ml small amount Physiological parameters: pulse rate at rest stroke volume blood minute volume at rest systolic blood pressure coronary blood flow at rest myocardial oxygen consumption at rest coronary reserve maximum minute blood volume less than 60 beats/min 100 ml More than 5 l/min Up to 120-130 mmHg 250 ml/min 30 ml/min Large 30-35 l/min 70-90 beats/min 50-70 ml 3 -5 l/min Up to 140-160 mmHg 250 ml/min 30 ml/min Small 20 l/min Vascular condition: vascular elasticity in the elderly Presence of capillaries on the periphery Elastic Large amount Lose elasticity Small amount Susceptibility to diseases: Atherosclerosis Hypertension myocardial infarction Weak Weak Weak Expressed Expressed Expressed
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