Oncotic blood pressure and its role. Osmotic and oncotic blood pressure

Understanding many medical terms is necessary even for a person who is not directly related to medicine. Moreover, there is a need to study a number of issues in those patients who want to understand their problem in depth in order to independently understand the meaning of conducting certain examinations, as well as therapeutic regimens.

One such term is oncoosmolar pressure. Most people do not know or simply do not understand what this term actually means, and try to link it with concepts about or some other cardiological constants.

What it is?

Oncotic blood pressure (the molecular compression of proteins on the surrounding tissues) is a certain part of the blood pressure created by the plasma proteins in it. Oncotic tone (in literal translation- volume, mass) - colloid osmotic blood pressure, a kind of share of the osmotic tone created by the high molecular weight components of the saline solution.

The molecular compression of proteins has importance for the life activity of the organism. Decrease in the concentration of protein in the blood (hypoproteinemia may be due to the fact that the most different reasons: fasting, disruption of the gastrointestinal tract, loss of protein in the urine in kidney disease) causes a difference in oncoosmolar blood pressure in tissue fluids and blood. Water definitely tends towards a greater tone (in other words, in the tissue), as a result of which the so-called protein, protein edema of the subcutaneous fatty tissue occurs (they are also called "hungry" and "renal" edema). When assessing the condition and determining the tactics of managing patients, taking into account osmo-oncotic phenomena is simply of great importance.

The thing is that only it is able to guarantee the retention of the proper amount of water in the blood. The probability of this development arises for the simple reason that almost all proteins, highly specific in their structure and nature, concentrating directly in the circulating blood plasma, pass through the walls of the hematomicrocirculatory bed into the tissue environment with great difficulty and make the oncotic tone necessary to ensure the considered process.

Only the gradient flow created by the salts themselves and some especially large molecules of highly organized organic compounds can have an identical value both in the tissues themselves and in the plasma fluid circulating throughout the body. In all other situations, the protein-osmolar pressure of blood in any scenario will be several orders of magnitude higher, because in nature there is a certain gradient of onco-osmolar tone, which is due to the ongoing fluid exchange between the plasma and absolutely all tissue fluid.

The given value can only be provided by specific albumin proteins, since the blood plasma itself concentrates most of all albumins, the highly organized molecules of which are slightly smaller in size than those of other proteins, and their dominant concentration in plasma is several orders of magnitude higher.

If the concentration of proteins decreases for one reason or another, then tissue edema occurs due to an excessive loss of water in the blood plasma, and with their growth, water is retained in the blood, and in large quantities.

From all of the above, it is easy to guess that oncoosmolar pressure itself plays an important role in the life of every person. It is for this reason that doctors are interested in all conditions that, one way or another, can be associated with dynamic changes pressure of fluid circulating in vessels and tissues. Taking into account the fact that water tends to both accumulate in vessels and be excessively excreted from them, numerous pathological conditions can manifest in the body, which clearly require appropriate correction.

So the study of the mechanisms of saturation of tissues and cells with fluid, as well as the pathophysiological nature of the influence of these processes on the ongoing changes in the blood pressure of the body, is a paramount task.

Norm

The value of the protein-osmolar flow varies within 25-30 mm Hg. (3.33-3.99 kPa) and 80% is determined by albumins due to their small size and the highest concentration in blood plasma. The indicator plays a fundamentally important role in the regulation water-salt metabolism in the body, namely in its retention in the blood (hematomicrocirculatory) vascular bed. The flow affects the synthesis of tissue fluid, lymph, urine, as well as the absorption of water from the intestines.

With a decrease in the value of protein-osmolar blood pressure in plasma (which happens, for example, with various pathologies liver - in such situations, the formation of albumins decreases, or kidney diseases, when the excretion of proteins in the urine increases), edema occurs, since water is not well retained in the vessels and gradually migrates into the tissues.

In human plasma, the constant of protein-osmolar blood pressure is only about 0.5% of osmolarity in value (translated into other values, this figure is a multiple of 3-4 kN / m², or 0.03-0.04 atm). Nevertheless, even taking into account this feature, protein-osmolar pressure plays a decisive role in the synthesis of intercellular fluid, primary urine, etc.

The capillary wall is completely freely permeable to water and some low-molecular biochemical compounds, but not to peptides and proteins. The rate of fluid filtration through the capillary wall is determined by the difference between the protein-molar pressure exerted by plasma proteins and the hydrostatic blood pressure provided by the work of the heart. The mechanism of formation of the norm of the oncotic pressure constant can be represented as follows:

1. At the arterial end of the capillary, the saline solution, together with nutrients, moves into the intercellular space.
2. At the venous end of the capillary, the process occurs in exactly the opposite direction, because the venous tone is in any case lower than the value of the protein-osmolar pressure.
3. As a result of this complex of interactions, biochemical substances released by cells pass into the blood.

With the manifestation of pathologies, accompanied by a decrease in the concentration of proteins in the blood (especially albumin), the oncotic tone is significantly reduced, and this can become one of the reasons for the collection of fluid in the intercellular space, resulting in the occurrence of edema.

The protein-osmolar pressure realized by homeostasis is quite important for ensuring the normal functioning of the body. A decrease in the concentration of protein in the blood, the causes of which can be hypoproteinemia, starvation, loss of protein in the urine in kidney pathology, various problems in the activity of the digestive tract, causes a difference in the numbers of oncoosmotic pressure in tissue fluids and blood. Accordingly, when assessing the objective state and treating patients, taking into account the existing osmo-oncotic phenomena is of fundamental importance.

The increase in the level can only be ensured by entering the bloodstream high concentrations albumin. Yes, this indicator can be maintained by proper nutrition (provided there is no primary pathology), but the condition is corrected only with the help of infusion therapy.

How to measure

Methods for measuring oncoosmolar blood pressure are usually differentiated into invasive and non-invasive. In addition, clinicians distinguish direct and indirect types. The direct method will definitely be used for, and the indirect method -. Indirect measurement in practice is always implemented using Korotkov's auscultatory method - in fact, starting from the obtained indicators, during this event, doctors will be able to calculate the oncotic pressure indicator.

To be more precise, in this situation it becomes possible only to answer the question as to whether the onco osmotic pressure, or not, because in order to accurately identify this indicator, it will definitely be necessary to know the concentrations of the albumin and globulin fractions, which is associated with the need to conduct a number of complex clinical diagnostic studies.

It is logical to assume that if they often vary, then this is not the most in the best way reflects on the patient's condition. In this case, the pressure can increase both due to a strong pressure of blood in the vessels, and decrease with an excessive release of fluid from the cell membranes into nearby tissues. In any case, it is necessary to carefully monitor your condition and dynamics.

Let us consider the case when a membrane with selective permeability is located on the path of diffusion of particles of a solute and a solvent, through which molecules of the solvent freely pass, and the molecules of the solute practically do not pass. The best selective permeability is possessed by membranes made from natural tissues of animal and plant origin (walls of the intestines and bladder, various plant tissues).

Osmosis is the spontaneous diffusion of solvent molecules through a membrane with selective permeability.

Rice. 6.7. Osmosis in a solvent-solution system separated by a membrane with selective permeability

Greater mobility of solvent molecules in a pure solvent than in a solution, where there is an intermolecular interaction between the substance and the solvent, which reduces the mobility of the solvent molecules.

Appearing excess hydrostatic pressure in the system is a consequence of osmosis, so this pressure is called osmotic.

osmotic pressure ( ) is called the excess hydrostatic pressure that occurs as a result of osmosis and leads to equalization of the rates of mutual penetration of solvent molecules through a membrane with selective permeability.

W. Pfeffer and J. van't Hoff, studying the quantitative dependence of osmotic pressure on external factors, found that it obeys the combined Mendeleev-Clapeyron gas law:

where c is the molar concentration of a substance in solution, mol/l.

From this equation it can be seen that the osmotic pressure does not depend on the nature of the solute, but depends only on the number of particles in the solution and on the temperature. However, this equation is valid only for solutions in which there is no interaction of particles, i.e., for ideal solutions. In real solutions, intermolecular interactions take place between the molecules of the substance and the solvent, which can lead either to the dissociation of the molecules of the solute into ions, or to the association of the molecules of the solute with the formation of associates from them.

The dissociation of substance molecules in an aqueous solution is characteristic of electrolytes (see Section 7.1). As a result of dissociation, the number of particles in the solution increases.

Association is observed if the molecules of a substance interact better with each other than with solvent molecules. As a result of association, the number of particles in solution decreases.

To take into account intermolecular interactions in real solutions, van't Hoff suggested using isotonic coefficient l. For solute molecules physical meaning isotonic ratio:

For solutions of non-electrolytes, whose molecules do not dissociate and are little inclined to association, i= 1.

For aqueous solutions of electrolytes due to dissociation i > 1, and its maximum value (l max) for a given electrolyte is equal to the number of ions in its molecule:

For solutions in which the substance is in the form of associates, i< 1, which is typical for colloidal solutions. For solutions of proteins and macromolecular substances, the value i depends on the concentration and nature of these substances (section 27.3.1).

Taking into account intermolecular interactions, the osmotic pressure for real solutions equals:

This equation correctly reflects the experimentally observed osmotic pressure of solutions with the same mass fraction substances, but different nature and the state of the solute in solution (Table 6.2).

During osmosis, the solvent molecules preferentially move through the membrane in the direction where the concentration of the particles of the substance is greater, and the concentration of the solvent is less. In other words, as a result of osmosis, the solvent is sucked into that part of the system where the concentration of particles of the substance is greater. If the osmotic pressure of the solutions is the same, then they are called isotonic and between them there is a truly equilibrium exchange of the solvent. In the case of contact of two solutions with different osmotic pressure hypertonic a solution is one whose osmotic pressure is greater, and hypotonic - solution with lower osmotic pressure. The hypertonic solution sucks up the solvent from the hypotonic solution, seeking to equalize the concentrations of the substance by redistributing the solvent between the contacting solutions.

An osmotic cell is a system separated from the environment by a selective permeability membrane. All cells of living beings are osmotic cells that are able to absorb a solvent from the environment or, conversely, give it away, depending on the concentrations of solutions separated by a membrane.

As a result of endoosmosis, water diffuses into the cell, the cell swells with the appearance of a stressed state of the cell, called turgor. In the plant world, turgor helps the plant to maintain an upright position and a certain shape.

Exoosmosis- the movement of the solvent from the osmotic cell to environment. Exoosmosis condition:

As a result of exoosmosis, water diffuses from the cell into the plasma and compression and wrinkling of the cell membrane occurs, called plasmolysis. Exoosmosis occurs when the cell is in a hypertonic environment. The phenomenon of exoosmosis is observed, for example, when sprinkling berries or fruits with sugar, and vegetables, meat or fish with salt. In this case, food canning occurs due to the destruction of microorganisms due to their plasmolysis.

When cooking saline solutions it is necessary to take into account their osmotic properties, therefore their concentration is expressed through osmolar concentration (osmolarity)(see Appendix 1).

Osmolar concentration- the total molar amount of all kinetically active, i.e., capable of independent movement, particles contained in 1 liter of solution, regardless of their shape, size and nature.

The osmolar concentration of a solution is related to its molar concentration through the isotonic coefficient c = ic(X).

The role of osmosis in biology and medicine. Osmosis is one of the reasons for the flow of water and substances dissolved in it from the soil along the stem or trunk of the plant to the leaves, since. The osmotic pressure of plant cells ranges from 5 to 20 atm, and in desert plants it even reaches 70 atm.

A feature of higher animals and humans is the constancy of osmotic pressure in many physiological systems especially in the circulatory system. The constancy of osmotic pressure is called isosmia. Human osmotic pressure is fairly constant and is 740-780 kPa (7.4-7.8 atm) at 37°C. It is mainly due to the presence in the blood of cations and anions of inorganic salts and to a lesser extent - the presence of colloidal particles and proteins. Presence in blood plasma shaped elements(erythrocytes, leukocytes, platelets and platelets) has almost no effect on osmotic pressure. The constancy of the osmotic pressure in the blood is regulated by the release of water vapor during respiration, the work of the kidneys, the release of sweat, etc.

Rice. 6.8. The role of blood oncotic pressure in capillary water exchange

The osmotic pressure of the blood, created by proteins in the blood plasma, is called oncotic pressure, although it is about 2.5-4.0 kPa, it plays an extremely important role in the exchange of water between blood and tissues, in its distribution between the vascular bed and the extravascular space.

Oncotic pressure- this is the osmotic pressure created due to the presence of proteins in the biofluids of the body.

The oncotic pressure of the blood is 0.5% of the total osmotic pressure of the blood plasma, but its value is commensurate with the hydrostatic pressure in the circulatory system (Fig. 6.8).

Rice. 6.9. Change of an erythrocyte in solutions with different osmotic pressure 77p _ pa:

a- isotonic solution(0.9% NaCl); b - hypertonic solution (2% NaCl); in - hypotonic solution (0.1% NaCl)

The hydrostatic pressure of the blood falls from the arterial part of the circulatory system to the venous one. If in the arterial part of the capillaries the hydrostatic pressure is greater than the oncotic pressure, then in the venous part it is less. This ensures the movement of water from arterial capillaries to interstitial fluid tissues, and venous capillaries, on the contrary, draw in intercellular fluid. Moreover, the intensity of such water transfer is directly proportional to the difference between P hydr and onc.

With a decrease in blood oncotic pressure, which is observed with hypoproteinemia (decrease in plasma protein content) caused by starvation, indigestion, or excretion of protein in the urine in kidney disease, the indicated pressure ratio p hydr and 0 HK is violated. This leads to a redistribution of fluid towards the tissues, and as a result, there are oncopic edema("hungry" or "renal").

The osmotic pressure of human blood corresponds to the osmolar concentration of particles from 290 to 300 mOsm/l. In medical and pharmaceutical practice isotonic(physiological) solutions call solutions characterized by the same osmotic pressure as blood plasma (Fig. 6.9, a). Such solutions are 0.9% NaCl solution (0.15 mol/l), in which i= 2, and 5% glucose solution (0.3 mol/l). In all cases, when bloodstream, muscle tissue, spinal canal, etc., solutions are administered for therapeutic purposes, it must be remembered that this procedure does not lead to an "osmotic conflict" due to the difference in osmotic pressures of the injected solution and this body system. If, for example, a solution is administered intravenously, hypertonic in relation to blood, then due to exoosmosis, erythrocytes will dehydrate and wrinkle - plasmolysis(Fig. 6.9, b). If the injected solution hypotonic in relation to blood, then there is an "osmotic shock" and due to endosmosis, a rupture of the erythrocyte membranes can occur - hemolysis(Fig. 6.9, in). The initial stage of hemolysis occurs with a local decrease in osmotic pressure to 360-400 kPa (3.5-3.9 atm), and complete hemolysis occurs at 260-300 kPa (2.5-3.0 atm).

A change in the osmotic balance in the biosystems of the body can be caused by metabolic disorders, secretory processes and food intake. In addition, every physical stress, which enhances metabolism, can contribute to an increase in the osmotic pressure of the blood. Despite these disturbances, the osmotic pressure of the blood is maintained constant, although the chemical composition of the blood can vary significantly. When osmotic hypertension of the blood occurs, the connective tissue located at the site of the violation gives water into the blood and takes salts from it almost immediately and until the osmotic pressure of the blood or tissue fluid returns to its normal value. After this quick reaction, the kidneys turn on, which respond to an increase in the amount of any salts by increasing their excretion until it is restored. normal composition connective tissue and blood. The osmotic pressure of urine, while maintaining the norm, can vary from 7.0 to 25 atm (690-2400 kPa). Such regulation has certain limits, and therefore, to strengthen it, water or salts from outside may be required. This is where the autonomic nervous system comes into play. Feeling thirsty after physical work (increased metabolism) or with kidney failure (accumulation of substances in the blood due to insufficient excretion) is a manifestation osmotic hypertension. The reverse phenomenon is observed in the case of salt starvation, causing osmotic hypotension.

Inflammation occurs as a result of a sharp local increase in metabolism. The cause of inflammation can be various effects - chemical, mechanical, thermal, infectious and radiation. Due to the increased local metabolism, the breakdown of macromolecules into smaller molecules increases, which increases the concentration of particles in the focus of inflammation. It leads to local increase osmotic pressure, release into the focus of inflammation a large number fluid from surrounding tissues and exudate formation. In medical practice, they use hypertonic solutions or gauze bandages moistened with a hypertonic NaCl solution, which, in accordance with the laws of osmosis, absorbs liquid into itself, which contributes to the constant cleansing of the wound from pus or the elimination of edema. In some cases, for the same purpose, ethanol or its concentrated aqueous solutions, which are hypertonic relative to living tissues. Their disinfecting action is based on this, since they contribute to the plasmolysis of bacteria and microorganisms.

The action of laxatives - bitter salt MgS0 4 7H2O and Glauber's salt Na 2 S04 10H2O is also based on the phenomenon of osmosis. These salts are poorly absorbed through the intestinal walls, so they create a hypertonic environment in it and cause a large amount of water to enter the intestine through its walls, which leads to a laxative effect. It should be borne in mind that the distribution and redistribution of water in the body occurs in other more specific mechanisms but osmosis

Introduction

1. Oncotic pressure of blood plasma. The value of this constant for water-salt exchange between blood and tissues

2. General characteristics of factors (accelerates) of blood coagulation. First phase of blood clotting

3. Cardiovascular center: its localization, features of functioning

4. Systemic blood pressure, the main hemodynamic factors that determine its value

5. Composition and enzymatic properties of pancreatic juice, mechanisms of regulation of its secretion. The meaning of bile

6. Neuro-reflex regulation of breathing: receptors, nerve centers, effectors

Conclusion

Bibliography

Introduction

Physiology is the science of the life of an organism as a whole, its interaction with the environment and the dynamics of life processes. This also determines the methods of physiological research. Physiology studies only living organisms.

Physiology widely uses chemical and physico-chemical methods of research, since the properties of a living organism are the metabolism and energy, that is, chemical and physical processes.

1. Oncotic pressure of blood plasma. The value of this constant for water-salt exchange between blood and tissues

The oncotic pressure of blood plasma depends mainly on the concentration of proteins, their size and hydrophilicity (the ability to retain water). The osmotic pressure of aqueous solutions is due to salts. Oncotic pressure (ONP) is of great importance in the distribution of water and substances dissolved in it between the blood and tissues. OnD blood averages 7.5-8.0 atmospheres.

The osmotic pressure of blood, lymph and tissue fluid is normally maintained at a constant level, although it may vary slightly, for example, with abundant intake of water or salts into the blood, but for a short time. The pressure is quickly equalized due to the activity of the excretory organs (kidneys, sweat glands), which remove excess water or salts.

When injected into the blood (intravenously or intraarterially) medicinal substances or saline solutions, it is necessary to ensure that their osmotic pressure is the same as the osmotic pressure of the blood.

Physiological solutions are still not equivalent to blood plasma, since they do not contain high-molecular colloidal substances, which are plasma proteins. Therefore, various colloids are added to the saline solution with glucose, for example, water-soluble high molecular weight polysaccharides (dextran), or specially processed protein preparations. Colloidal substances are added in the amount of 7-8%. Such solutions are administered to a person, for example, after a large blood loss. However, the best blood-substituting fluid is still blood plasma.

2. General characteristics of factors (accelerates) of blood coagulation. First phase of blood clotting

Many substances are involved in the process of blood clotting. Twelve of these are called clotting factors; they are numbered I through XIII because factor VI turned out to be the same factor as factor V. This list of 12 factors, however, is incomplete, and other substances, such as ADP and serotonin, are involved in the clotting process.

Hemostasis, or clot formation, begins with the vascular stage: a 30-minute period that begins when the wall of a blood vessel is damaged. Vascular spasm (angiospasm) leads to a decrease in blood loss in large vessels and can even completely stop capillary blood loss. The initial damage to the walls of the vessels, together with their spasm, causes a change in the basement membrane. The walls become “sticky”, which helps not only to retain platelets, but also to seal small vessels. All this is the result of the release of chemicals (including hormones local action) by the walls of blood vessels, which, however, initiates the second stage: hemostasis - platelet.

3. Cardiovascular center: its localization, features of functioning

The heart is a hollow muscular organ divided by a longitudinal septum into right and left halves isolated from each other. Each of them consists of an atrium and a ventricle separated by fibrous septa. One-way blood flow from the atria to the ventricles and from there to the aorta and pulmonary artery provided by valves located at the inlet and outlet of the ventricles. The opening and closing of the valves depend on the magnitude of the pressures on both sides.

The muscle fibers of the heart contain myofibrils, having a transverse striation. The diameter of muscle fibers is 12-24 microns, the length can reach 50 microns.

Wall thickness different departments hearts is not the same. This is due to differences in the power of the work performed. The greatest work is performed by the muscles of the left ventricle, the wall thickness of which reaches 10-15 mm. The walls of the right ventricle are somewhat thinner (5-8 mm), even thinner than the walls of the atria (2-3 mm).

Heart sizes due to the volume of its cavities and wall thickness. These values ​​depend on body size, age, sex and motor activity person. The dimensions of the heart are determined by radiography, the volumes of the cavities are determined by radiocardiography (the introduction of radioactive substances into the blood and the registration of blood passing through the heart using Geiger-Muller counters). In healthy adult men of average height and weight, the length of the heart is on average 14 cm, the diameter is 12 cm, the volume of the ventricular cavities is 250-350 ml. In women, these values ​​are somewhat less.

Total heart volume determined using special method- biplane teleradiography. Pictures of the heart are taken in two projections. Based on the values ​​obtained, the volume of the heart is calculated. On average, it is 700-900 ml for men and 500-600 ml for women. Heavy physical work and sports contribute to the development of myocardial hypertrophy and lead to an increase in the volume of the heart cavities.

The heart is supplied with blood through coronary arteries, starting at the exit of the aorta. Blood enters the coronary arteries during the relaxation of the heart. With the contraction of the ventricles, the entrance to the coronary arteries is covered by the semilunar valves, and the arteries themselves are compressed by the contracted muscle of the heart. Therefore, the blood supply to the heart decreases with its contraction. About 200-250 ml of blood per minute enters the coronary arteries. At physical work the blood supply to the heart increases. The volume of blood flowing to it depends on the power of the work performed. With very hard work, the blood supply to the heart can increase to 1000 ml.

The cardiac muscle has the ability to automaticity, excitability, conductivity and contractility.

Automatic heart. The ability of the heart to contract rhythmically without external stimuli, under the influence of impulses that arise in itself, is called the automatism of the heart. Excitation in it arises at the confluence of the hollow veins in right atrium. Here is an accumulation of atypical muscle tissue called the sinoatrial node or Keys-Flak node. atypical muscle in its structure differs from the bulk of the myocardium. The cells of this tissue are rich in protoplasm, while the transverse striation in them is less pronounced.

Arising in the sinoatrial node - main pacemaker of the heart- excitation spreads to the atrioventricular node located in the right atrium in the interatrial septum. The bundle of His departs from this node, it is divided into two legs, the branches of which, called Purkin's fibers, conduct excitation to the muscles of the ventricles.

The sinoatrial node has the most pronounced automaticity. AT normal conditions impulses from this part of the heart provide the activity of all the others. Automation of other areas of the myocardium, in particular the atrioventricular node, is less pronounced. It is suppressed by impulses from the main pacemaker of the heart.

If, for example, the sinoatrial node is isolated from a frog (by cutting or cooling the corresponding sections of the heart), then the activity of the heart temporarily stops. Then its contractions arise again, but their rhythm will be less frequent than it was before the isolation of the main pacemaker. This experiment, first carried out by Stannius, proves the leading role of the sinoatrial node for normal operation hearts.

Automation of heart pacemakers due to periodic changes in membrane potentials in their cells. During diastole, a gradual depolarization of the membrane occurs. At the moment when its potential is significantly reduced, there is an excitation that spreads through all myocardial fibers. Periodically occurring depolarization of cell membranes is due to a change in their permeability. According to some data, during diastole, the release of potassium ions from the cells decreases, according to others, on the contrary, the flow of sodium ions there increases. As a result, the concentration of sodium and potassium ions on both sides of the membrane begins to change, which leads to its depolarization. The significance of sodium ions for the occurrence of excitation processes in cells - pacemakers is confirmed more high content here sodium compared with other areas of the myocardium.

Excitability of the heart. It manifests itself in the occurrence of excitation under the action of various stimuli. The strength of the stimulus in this case should be at least the threshold. Under certain conditions, threshold stimuli cause contractions of maximum force. This feature of the occurrence of excitation in the heart is called the law of "all or nothing." However, this law does not always manifest itself. The degree of contraction of the heart muscle depends not only on the strength of the stimulus, but also on the magnitude of its preliminary stretch, as well as on the temperature and composition of the blood that feeds it.

The excitability of the heart muscle is unstable. It changes in the course of excitation. In its initial period, the heart muscle is immune (refractory) to repeated irritations. This period is called phase of absolute refractoriness. In humans, it lasts 0.2-0.3 seconds, i.e., it coincides with the time of contraction of the heart. At the end of the phase of absolute refractoriness, the excitability of the heart muscle is gradually restored and at a very a short time becomes higher than the original.

Due to the long period of absolute refractoriness, the heart muscle in normal conditions cannot contract like a tetanus, which is very important for coordinating the work of the atria and ventricles.

Under the action of frequent stimuli, the heart muscle does not respond to those that come in the phase of absolute refractoriness. If an additional extraordinary impulse acts on the heart at the moment when its excitability has already been restored, then an additional contraction of the heart occurs, called an extrasystole. The next regular impulse at the same time gets to the heart in the phase of its refractoriness. The heart does not respond to it, and therefore, after an extrasystole, an elongated (compensatory) pause is observed.

conduction of the heart. It ensures the spread of excitation from pacemaker cells throughout the myocardium. The spread of excitation through the heart is carried out electrically. An action potential generated in one muscle cell is an irritant for others. The ability to conduct excitation depends on the structural features of the muscle fibers of the heart and on many other factors. For example, it increases with increasing temperature and decreases with a lack of oxygen. Different parts of the heart have different conductivities. It depends on the content of glycogen in them and on the duration of the refractory phases. The peripheral ramifications of the conduction system of the heart are located directly below the endocardium. Therefore, excitation primarily covers the inner layers of the heart and then spreads outwards. As a result, the rate of propagation of excitation through the heart depends not only on the characteristics of the conduction system, but also on the thickness of the muscle walls.

The cells of the conduction system of the heart, and especially the Purkinė fibers, have the highest conductivity. The speed of the conduction of excitation from the muscle fibers of the atria to the atroventricular node is low. The delay in the propagation of the excitatory process that occurs here ensures consistency in the work of the atria and ventricles.

The source of energy for the contraction of the heart muscle are high-energy phosphorus-containing substances. Their restoration occurs due to the energy released during respiratory and glycolytic phosphorylation. In this case, aerobic reactions are predominant.

4. Systemic blood pressure, the main hemodynamic factors that determine its value

One of the most important hemodynamic parameters is systemic blood pressure, those. pressure in primary departments circulatory system - in large arteries. Its magnitude depends on the changes taking place in any department of the system.

Along with the systemic, there is the concept of local pressure, i.e. pressure in small arteries, arterioles, veins, capillaries. This pressure is less, the longer the path traveled by the blood to this vessel when it leaves the ventricle of the heart. So, in the capillaries, the blood pressure is greater than in the veins, and is equal to 30-40 mm (beginning) - 16-12 mm Hg. Art. (the end). This is explained by the fact that the longer the blood travels, the more energy is spent on overcoming the resistance of the vessel walls, as a result, the pressure in the vena cava is close to zero or even below zero.

The main hemodynamic factors influencing the amount of systemic blood pressure, are determined from the formula:

Q \u003d P * p * r 4 / 8 * Yu * ​​l,

Where Q is the volumetric blood flow velocity in this body, r - the radius of the vessels, P - the difference in pressure on the "inhale" and "exhale" from the body.

The value of systemic arterial pressure (BP) depends on the phase of the cardiac cycle.

Systolic BP created by the energy of heart contractions in the systole phase, is 100-140 mm Hg. Art. Its value depends mainly on the systolic volume (ejection) of the ventricle (CO), total peripheral resistance (R) and heart rate. Diastolic BP created by the energy accumulated in the walls large arteries when stretched during systole. The value of this pressure is 70-90 mm Hg. Art. Its value is determined, to a greater extent, by the values ​​of R and heart rate. The difference between systolic and diastolic pressure is called pulse pressure, because it determines the range of the pulse wave, which is normally equal to 30-50 mm Hg. Art.

Systolic pressure energy spent: 1) to overcome resistance vascular wall(lateral pressure - 100-110 mm Hg); 2) to create the speed of moving blood (10-20 mm Hg - shock pressure).

An indicator of the energy of a continuous flow of moving blood, the resulting "value of all its variables is artificially allocated average dynamic pressure. It can be calculated by D. Hynem's formula: P mean = P diastolic + 1/3P pulse. The value of this pressure is 80-95 mm Hg. Art.

Blood pressure also changes in connection with the phases of respiration: on inspiration, it decreases.

BP is a relatively mild constant: its value can fluctuate during the day: during physical work of great intensity, systolic pressure can increase by 1.5-2 times. It also increases with emotional and other types of stress. On the other hand, the blood pressure of a healthy person may decrease relative to its medium size. This is observed during slow sleep and - for a short time - with orthostatic perturbation associated with the transition of the body from a horizontal to a vertical position.

The highest values ​​of systemic blood pressure at rest are recorded in the morning; many people also have a second peak at 15-18 hours.

5. Composition and enzymatic properties of pancreatic juice, mechanisms of regulation of its secretion. The meaning of bile

pancreatic juice has alkaline reaction, its pH is 7.8-8.4. He contains enzymes that break down proteins as well as high molecular weight polypeptides, carbohydrates and fats. The protein enzyme trypsin is secreted by the gland in an inactive state. It is activated by intestinal juice enterokinase. The action of the enzyme lipase, which breaks down fats, is enhanced by bile.

Secretion pancreatic juice occurs under the influence of nervous and humoral factors. It occurs under the action of conditioned and unconditioned stimuli. Conditioned reflex secretion of pancreatic juice begins at the sight and smell of food, and in humans even when talking about it. During the act of eating, mechanical irritation of the receptors of the oral cavity and pharynx occurs. Signals from here, entering the medulla oblongata, cause the release of pancreatic juice by the mechanism unconditioned reflexes. The secretory nerves of the pancreas are fibers of the vagus nerve.

Chemical pathogens of the pancreas are hormones produced by the mucous membrane of the duodenum. Chief among them - secretin. It is excreted in an inactive form, activated by hydrochloric acid and, entering the bloodstream, stimulates the secretion of the pancreas.

Secretion of pancreatic juice begins in 2-3 minutes. after a meal and lasts 6-14 hours. The amount of juice secreted and its enzymatic composition depend on the amount and composition of the incoming food. When eating bread, the greatest secretion of the pancreas is observed in the first hour of digestion, when eating meat - in the second, milk - in the third. Fatty food produces relatively little sap.

Liver cells continuously secrete bile, which is one of the most important digestive juices. Between meals, bile accumulates in the gallbladder. It's happening here reverse suction its liquid part. Therefore, bladder bile is thicker in consistency and darker in color than bile secreted directly from the liver.

Bile activates the enzymes of the pancreatic and intestinal juices, especially lipase. The value of bile for the digestion of fat is very high. It emulsifies fats and increases solubility fatty acids which facilitates their absorption. By increasing the alkaline reaction in the intestine, bile prevents the destruction of trypsin by pepsin. In addition, it stimulates the movements of the intestines and, having bactericidal properties, delays putrefactive processes in the intestines. A person produces about 500 -700 ml of bile. Increased bile formation during digestion and the release of bile from the bladder into the intestine occur under the influence of nervous and humoral influences. The sight and smell of food, the act of eating, irritation of the receptors of the stomach and duodenum with food masses increase bile formation and cause the release of bile into the intestine by the mechanism of conditioned and unconditioned reflexes. The secretory nerve of the liver is nervus vagus. The sympathetic nerve causes inhibition of bile formation and the cessation of the evacuation of bile from the bladder.

6. Neuro-reflex regulation of breathing: receptors, nerve centers, effectors

The intensity of oxidative processes in the body is not constant: during rest it is relatively small, during mental and physical work it increases significantly. The increased need for oxygen is met by a corresponding increase in the activity of the respiratory and cardiovascular systems.

Changing breathing in accordance with the needs of the body is achieved through a complex system of neuro-humoral effects on respiratory center. Lung ventilation may increase or decrease depending on: a) chemical composition blood flowing through the respiratory center (i.e., by the humoral route); b) afferent signals coming to the respiratory center from various receptors, i.e., in the order of an unconditioned reflex, and c) impulses coming to the respiratory center from the cerebral cortex, i.e., according to the mechanism conditioned reflex. Under natural conditions, humoral (through the blood) and nervous mechanisms of regulation operate in unity with each other.

Respiratory center. Respiration is controlled by the respiratory center. It is a collection nerve cells in the medulla oblongata, from which impulses are sent to the spinal centers that directly innervate the respiratory muscles. The activity of the respiratory center is influenced by the higher parts of the central nervous system especially the cerebral cortex. Due to this, a complex voluntary regulation of breathing is carried out, for example, when talking, singing, doing physical exercises, etc.

In 1912, Legallois showed that if an injection is made in a certain place in the medulla oblongata, then breathing stops completely. This phenomenon was later investigated by Flurans and N. A. Mislavsky. The region of the medulla oblongata, which is necessary for the periodic change of inhalation and exhalation, is called the respiratory center. In mammals and humans, the area directly involved in the innervation of respiratory movements is located in the bottom of the IV ventricle in the reticular formation of the medulla oblongata.

The respiratory center is a paired formation, each half of which innervates the respiratory muscles of the same half of the body. According to N. A. Mislavsky, it is divided into the center of inspiration (inspiratory center) and the center of exhalation (expiratory center). Modern electrophysiological studies using microelectrode technology have confirmed the presence of various neurons, the stimulation of which causes either inhalation or exhalation. At present, more than complex structure respiratory center. It turned out that in the pons there are pneumotaxic and apneustic centers that control the underlying centers of inhalation and exhalation and participate in the organization of the normal alternation of respiratory movements.

Volleys of nerve impulses periodically occur in the respiratory center, which through motor neurons spinal cord cause respiratory movements. Respiratory rhythm can be observed even on the brain removed from the body of an animal. This fact was one of cornerstones the doctrine of the automatic activity of the respiratory center. The automatism of the respiratory center is its ability to be periodically excited under the influence of stimuli present or arising in itself. In the conditions of an integral organism of an animal and a person, a constantly acting irritant of the respiratory center is carbon dioxide, which is in the blood, washing the medulla oblongata. Like the heart, the respiratory center responds to constant irritation with intermittent bursts of excitation. However, if in the heart this periodicity is due to a long refractory phase, then in the natural conditions of the work of the respiratory center it is carried out reflexively. Afferent signals arriving at the respiratory center with each breath from the interoreceptors of the lungs and the proprioreceptors of the respiratory muscles periodically inhibit the activity of the respiratory center, transforming its response to a continuously acting chemical stimulus in the form of rhythmically occurring bursts of excitation.

Innervation of the respiratory muscles. The pathways carrying impulses from the respiratory center descend into the spinal cord and end near the motoneurons of the phrenic and intercostal nerves. Impulses sent to the respiratory centers excite these neurons, which, in turn, send impulses to the respiratory muscles. Thus, in accordance with the periodic excitation of the respiratory center, periodic contractions of the respiratory muscles occur. They arise under the influence of efferent impulses sent to them by nerve centers.

The respiratory muscles are innervated spinal nerves. The paired phrenic nerve, which innervates the diaphragm, emerges from the cervical part of the spinal cord, and the intercostal nerves, which supply the intercostal muscles, originate in the thoracic part of the spinal cord.

The motor neurons of the spinal cord, innervating the respiratory muscles, cannot independently ensure the functioning of the respiratory apparatus, they are entirely subordinate to the respiratory center of the brain. Indeed, if the spinal cord is cut in the middle of its thoracic part, then the respiratory movements of the chest below the section of the section stop. If the incision is made slightly higher - between the thoracic and cervical parts spinal cord, then only diaphragmatic breathing, the intercostal muscles completely lose their ability to contract. After separation of the spinal cord from the medulla, the movements of the diaphragm are also paralyzed. When transected between the medulla oblongata and midbrain, respiratory movements do not stop. In this regard, it is obvious that the place of occurrence of impulses that periodically excite the respiratory muscles is located in the medulla oblongata, where the cells of the respiratory center are located. The significance of shifts in the gas composition of the blood for the regulation of respiration. An important role in the regulation of respiration is played by a change in the carbon dioxide content of oxygen in the blood flowing through the respiratory center. In the process of stimulation of mechanoreceptors for the regulation of respiration, it consists in a periodic change of inhalations and exhalations, due to signals sent to the respiratory center, the main role is played by the vagus nerve, in the trunk of which afferent fibers from interoreceptors located in the wall of the lungs pass.

Conclusion

Physiology belongs to biological disciplines. The main object of study of physiology, as well as a number of other biological sciences, is the life of the organism.

Physiology studies the processes taking place in the body, starting with the primitive functions of the irritability of living matter to the highest manifestations of the life of the organism in its interaction with the external environment.

The task of physiology is to study the life processes occurring in the human or animal body, in their relationship, to establish a causal relationship between them, the general patterns underlying them, to trace their evolution, to reveal the qualitative originality of the processes occurring in a living organism, and identifying qualitative differences physiological processes at different stages of animal development.

In every organism, regardless of whether it is unicellular or multicellular, physiological processes take place.

These processes become more complex as the organic world develops. In an animal with a more complex organization, they acquire a more complex character. The study of physiological processes in animals at different levels of the zoological ladder helps to reveal the patterns underlying these processes in more highly organized animals, and thereby contributes to their knowledge.

Man is the most highly organized living being, and although the physiological functions observed in animals are also carried out in the human body, they are qualitatively different from physiological functions animals.

Bibliography

1. Zimkin N.V. "Human Physiology" - Moscow: Physical Culture and Sport, 2008-496 p.

3. Loginov A.V. "Physiology with the basics of human anatomy" - Moscow: Medicine, 2008-496 p.

4. Markosyan A.A. "Physiology" - Moscow: Medicine, 2007-350 p.

5. Sapin M.R. "Anatomy and Physiology" - Moscow: Academy, 2009-432 p.

A membrane that is only permeable to solvent molecules (semi-permeable membrane) at which osmosis stops. Osmosis is the spontaneous penetration (diffusion) of solvent molecules through a semipermeable membrane into a solution or from a solution with a lower concentration into a solution with a higher concentration.

Osmotic pressure is measured using osmometers. The diagram of the simplest osmometer is shown in the figure.

Osmometer scheme: 1- water; 2 - cellophane bag (semi-permeable); 3 - solution; 4 - glass tube; h is the height of the liquid column (a measure of osmotic pressure).

Films made of cellophane, collodion, etc. are used as semipermeable membranes.

Osmotic pressure of dilute solutions of non-electrolytes at constant temperature proportional to the molar concentration of the solution, and at a constant concentration - the absolute temperature. Solutions with equal osmotic pressure are called isotonic. A solution with a high osmotic pressure is called hypertonic, and a solution with a lower osmotic pressure is called hypotonic.

Osmosis and osmotic pressure play an important role in the exchange of water between cells and their environment. The osmotic pressure of human blood is normally equal to 7.7 atm on average and is determined by the total concentration of all substances dissolved in the plasma. Part of the osmotic pressure of the blood, determined by the concentration of plasma proteins and normally equal to 0.03-0.04 atm, is called oncotic pressure. Oncotic pressure plays a significant role in the distribution of water between the blood and lymph.

Osmotic pressure is the external pressure on a solution, separated from a pure solvent by a semi-permeable membrane, at which osmosis stops. Osmosis is the one-sided diffusion of a solvent into a solution through a semi-permeable membrane separating them (parchment, animal bladder, films of collodion, cellophane). Membranes of this kind are permeable to the solvent, but do not allow solutes to pass through. Osmosis is also observed when a semi-permeable membrane separates two solutions with different concentrations, while the solvent moves through the membrane from a less concentrated solution to a more concentrated solution. The value of the osmotic pressure of a solution is determined by the concentration of kinetically active particles (molecules, ions, colloidal particles) in it.

Osmotic pressure is measured using devices called osmometers. The scheme of the simplest osmometer is shown in fig. Vessel 1 filled with the test solution, the bottom of which is a semi-permeable membrane, is immersed in vessel 2 with pure solvent. As a result of osmosis, the solvent will pass into vessel 1 until the excess hydrostatic pressure, measured by a liquid column of height h, reaches a value at which osmosis stops. In this case, an osmotic equilibrium is established between the solution and the solvent, characterized by the equality of the rates of passage of solvent molecules through a semipermeable membrane into the solution and solution molecules into the solvent. The excess hydrostatic pressure of a liquid column of height h is a measure of the osmotic pressure of a solution. The determination of the osmotic pressure of solutions is often carried out by an indirect method, for example, by measuring the decrease in the freezing point of solutions (see Cryometry). This method is widely used to determine the osmotic pressure of blood, blood plasma, lymph, urine.

The osmotic pressure of isolated cells is measured by plasmolysis. To do this, the cells under study are placed in solutions with different concentrations of a solute, for which cell wall impenetrable. Solutions with an osmotic pressure greater than the osmotic pressure of the cell contents (hypotonic solutions) cause cell shrinkage (plasmolysis) due to the release of water from the cell, solutions with an osmotic pressure lower than the osmotic pressure of the cell contents (hypotonic solutions) cause cells to swell as a result transfer of water from solutions to the cell. A solution with an osmotic pressure equal to the osmotic pressure of the contents of the cells is isotonic (see Isotonic solutions), does not change the volume of the cell. Knowing the concentration of such a solution, the osmotic pressure of the contents of the cell is calculated by equation (1).

The osmotic pressure of dilute solutions of non-electrolytes follows the laws established for the pressure of gases, and can be calculated using the van't Hoff equation:
n=sRT, (1)
where p is the osmotic pressure, c is the concentration of the solution (in moles per 1 liter of solution), T is the temperature on an absolute scale, R is a constant (0.08205 l atm / deg mol).

The osmotic pressure of an electrolyte solution is greater than the osmotic pressure of a non-electrolyte solution of the same molar concentration. This is explained by the dissociation of dissolved electrolyte molecules into ions, as a result of which the concentration of kinetically active particles in the solution increases. Osmotic pressure for dilute electrolyte solutions is calculated by the equation:

where i is the isotonic coefficient showing how many times the osmotic pressure of the electrolyte solution is greater than the osmotic pressure of the non-electrolyte solution of the same molar concentration.

The total osmotic pressure of human blood is normally 7-8 atm. Part of the osmotic pressure of blood, due to the macromolecular substances contained in it (mainly blood plasma proteins), is called oncotic, or colloid osmotic blood pressure, which is normally 0.03-0.04 atm. Despite its low value, oncotic pressure plays an important role in the regulation of water exchange between circulatory system and fabrics. The measurement of osmotic pressure is widely used to determine the molecular weight of biologically important macromolecular substances, such as proteins. Osmosis and osmotic pressure play an important role in the processes of osmoregulation, i.e. maintaining the osmotic concentration of dissolved substances in body fluids at a certain level. With the introduction various kinds liquids into the blood and into the intercellular space, isotonic solutions cause the least disturbance in the body, i.e., solutions whose osmotic pressure is equal to the osmotic pressure of the body fluid. See also Permeability.

Human health and well-being depend on the balance of water and salts, as well as the normal blood supply to organs. Balanced normalized exchange of water from one body structure to another (osmosis) is the basis healthy lifestyle life, as well as a means of preventing a number of serious illnesses(obesity, vegetovascular dystonia, systolic hypertension, heart disease) and a weapon in the fight for beauty and youth.

It is very important to maintain the balance of water and salts in the human body.

Nutritionists and doctors talk a lot about control and maintenance of water balance, but they do not delve into the origins of the process, dependencies within the system, and the definition of structure and relationships. As a result, people remain illiterate in this matter.

The concept of osmotic and oncotic pressure

Osmosis is the process of fluid transfer from a solution with a lower concentration (hypotonic) to an adjacent solution with a higher concentration (hypertonic). Such a transition is possible only under appropriate conditions: when liquids are “neighbored” and when a transmissive (semi-permeable) partition is separated. At the same time, they exert a certain pressure on each other, which in medicine is commonly called osmotic.

AT human body each biological fluid is just such a solution (for example, lymph, tissue fluid). And cell walls are "barriers".

One of key indicators the state of the body, the content of salts and minerals in the blood is the osmotic pressure

The osmotic pressure of the blood is an important vital sign, reflecting its concentration constituent elements(salts and minerals, sugars, proteins). It is also a measurable value that determines the force with which water is redistributed to tissues and organs (or vice versa).

It is scientifically determined that this force corresponds to the pressure in saline. So doctors call sodium chloride solution with a concentration of 0.9%, one of the main functions of which is plasma replacement and hydration, which allows you to fight dehydration, exhaustion in case of large blood loss, and it also protects red blood cells from destruction when drugs are administered. That is, with respect to blood, it is isotonic (equal).

Oncotic blood pressure component(0.5%) osmosis, whose value (required for normal functioning organism) ranges from 0.03 atm to 0.04 atm. Reflects the force with which proteins (in particular, albumins) act on neighboring substances. Proteins are heavier, but their number and mobility are inferior to salt particles. Because the oncotic pressure is much less than the osmotic pressure, however, this does not reduce its importance, which is to maintain the transition of water and prevent reabsorption.

No less important is such an indicator as oncotic blood pressure.

The analysis of the plasma structure, reflected in the table, helps to present their relationship and the significance of each.

Regulatory and metabolic systems (urinary, lymphatic, respiratory, digestive) are responsible for maintaining a constant composition. But this process begins with signals given by the hypothalamus, which responds to stimulation of osmoreceptors ( nerve endings in blood vessel cells).

The level of this pressure directly depends on the work of the hypothalamus.

For proper functioning and viability of the body, blood pressure must correspond to cellular, tissue and lymphatic pressure. With the correct and well-coordinated work of the body systems, its value remains constant.

It can grow rapidly with physical activity but quickly recovers.

How is osmotic pressure measured and its importance

Osmotic pressure is measured in two ways. The choice is made depending on the situation.

Cryoscopic method

It is based on the dependence of the temperature at which the solution freezes (depression) on the concentration of substances in it. Saturated ones have lower depression than dilute ones. For human blood normal pressure(7.5 - 8 atm) this value ranges from -0.56 ° C to - 0.58 ° C.

In this case, a special device is used to measure blood pressure - an osmometer.

Measurement with an osmometer

This is a special device, which consists of two vessels with a separating partition, which has a partial patency. Blood is placed in one of them, covered with a lid with a measuring scale, and a hypertonic, hypotonic or isotonic solution is placed in the other. The level of the water column in the tube is an indicator of the osmotic value.

For the life of an organism, the osmotic pressure of blood plasma is the foundation. It provides tissues with the necessary nutrients, monitors the healthy and proper functioning of systems, and determines the movement of water. In the case of its excess, erythrocytes increase, their membrane bursts (osmotic hemolysis), with a deficiency, the opposite process occurs - drying out. This process underlies the work of each level (cellular, molecular). All body cells are semi-permeable membranes. Fluctuations caused by incorrect circulation of water lead to swelling or dehydration of cells and, as a result, organs.

Oncotic pressure of blood plasma is irreplaceable in matters of treatment serious inflammation, infections, suppuration. Growing in the very place where the bacteria are located (due to the destruction of proteins and an increase in the number of particles), it provokes the expulsion of pus from the wound.

Remember that osmotic pressure affects the entire body as a whole.

Another one important role- influence on the functioning and life span of each cell. The proteins responsible for oncotic pressure are important for blood clotting and viscosity, maintaining the Ph-environment, and protecting red blood cells from sticking together. They also provide the synthesis and transport of nutrients.

What affects osmosis performance

Osmotic pressure indicators can change for various reasons:

• The concentration of non-electrolytes and electrolytes ( mineral salts) dissolved in plasma. This dependence is directly proportional. A high content of particles provokes an increase in pressure, as well as vice versa. Main component– ionized sodium chloride (60%). However, the osmotic pressure does not depend on the chemical composition. The concentration of cations and anions of salts is normal - 0.9%.
• Quantity and mobility of particles (salts). An extracellular environment with an insufficient concentration will receive water, an environment with an excess concentration will give it away.
• Oncotic pressure of plasma and blood serum, playing leading role in water retention blood vessels and capillaries. Responsible for the creation and distribution of all fluids. A decrease in its performance is visualized by edema. The specificity of functioning is due to the high content of albumins (80%).

The osmotic pressure is influenced by the salt content in the blood plasma

• electrokinetic stability. It is determined by the electrokinetic potential of particles (proteins), which is expressed by their hydration and the ability to repel each other and slide in solution conditions.
• Suspension stability, directly related to electrokinetic. Reflects the speed of connection of erythrocytes, that is, blood clotting.
• The ability of plasma components, when moving, to resist the flow (viscosity). With ductility, the pressure rises, with fluidity, it decreases.
• During physical work, osmotic pressure increases. A value of 1.155% sodium chloride causes a feeling of fatigue.
• Hormonal background.
• Metabolism. An excess of metabolic products, "pollution" of the body provokes an increase in pressure.

Osmosis rates are influenced by human habits, food and drink consumption.

The metabolism in the human body also affects the pressure.

How nutrition affects osmotic pressure

Balanced proper nutrition- one of the ways to prevent jumps in indicators and their consequences. The following dietary habits negatively affect the osmotic and oncotic blood pressure:

Important! Better not to let critical condition, but regularly drink a glass of water and monitor the mode of its consumption and excretion from the body.

About measurement features blood pressure You will be told in detail in this video: