How is pressure expressed. High and low blood pressure: the norm for age, preparations for stabilization

The man is complex mechanism, in the body of which all processes are interconnected. Blood pressure is one of the important indicators of health, its sudden changes can cause serious complications stroke, myocardial infarction, or coronary disease. Each person should know what factors provoke a change in pressure, how to properly measure it, and how preventive measures follow to normalize it.

What is blood pressure?

Blood pressure is the level of blood pressure on the walls of the arteries in the body. This is an individual indicator, its changes can be influenced by:

• the person's age;
• stressful situations;
• the presence of chronic pathologies;
• Times of Day;

Exists average rate arterial blood pressure 120/80 mm Hg. Art., from which doctors are repelled in the process of diagnosing a patient. Pressure is measured in millimeters of mercury and shows two numbers - upper and lower pressure.

Blood pressure is one of key indicators human health

1. Upper (systolic) - the pressure exerted by the blood at the time of maximum contraction of the heart.
2. Lower (diastolic) - blood pressure at the moment of maximum relaxation of the heart muscle.

Deviations of 20-30 mm Hg. Art. above or below the average of 120/80 mm Hg. Art. in an adult indicates possible diseases. Timely treatment protect against the spread of the disease to chronic form and severe complications.

Everyone should know about blood pressure and what it is to prevent possible diseases.

Mechanism of arterial regulation

In the human body, all processes are interconnected. The mechanism of arterial regulation is very complex, it is influenced by such things as the central and autonomic nervous system, endocrine system person.

The pressure fluctuates within its normal range due to such factors:

1. The movement of blood through the vessels (hemodynamics). Responsible for the level of blood pressure.
2. Neurohumoral regulation. Nervous and humoral regulation constitute common system, which has a regulating effect on the pressure level.

Blood pressure (BP) is the force exerted by blood on the walls of the arteries.

The nervous system reacts with lightning speed to changes in the body. During physical activity, at mental stress and stress, the sympathetic nervous system activates the excitation of cardiac activity and affects the speed of the heartbeat, which causes a change in pressure.

The kidneys perform important function to maintain blood pressure, they remove water and electrolytes from the body.

The kidneys secrete hormones and substances that are important humoral regulators:

1. They produce renin. This hormone is part of the renin-angiotensin system, which regulates pressure in the body, affects blood volume and vascular tone.
2. Form depressant substances. With the help of them, the arteries expand and the pressure decreases.

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Methods and rules for measuring indicators

Pressure can be measured directly indirect method. The direct (invasive) method of measuring pressure is used when inpatient treatment patient, when constant monitoring of the indicator is needed. It is produced using a catheter, the needle of which is inserted into the patient's lumen radial artery. The catheter itself is attached to a manometer to obtain pressure readings.

To measure blood pressure, classic tonometers with a phonendoscope are used.

The indirect (non-invasive) method of measuring pressure does not require direct contact with the bloodstream:

1. auscultatory or auditory method. Produced by a mechanical tonometer with a phonendoscope. The cuff squeezes the artery with the help of pumped air and the indicators are listened to in the form of noise that is emitted when blood passes through the artery.
2. Oscillometric method. It does not require noise listening and the indicators are displayed on the display of a digital tonometer. The most common measurement method that requires a minimum of effort and is convenient for daily use at home in the form of an electronic tonometer.

To get the correct readings of the tonometer when measuring pressure, you must follow these rules:

1. Blood pressure is measured in a sitting or lying position.
2. The patient should be in a relaxed state, not talking.
3. An hour before the measurement, you need to exclude food intake, two hours - alcohol and cigarettes.
4. The cuff worn on the arm is fixed at the level of the heart.
5. If the tonometer is semi-automatic, air is injected smoothly and without sudden movements.
6. The rolled-up sleeve of clothing should not squeeze the arm during the measurement process.

The normal blood pressure of a person directly depends on his age, lifestyle

The first home pressure measurements are best done on both hands. The hand on which the indicators turn out to be higher is used for constant measurements. It is believed that the pressure in right-handers will be higher on the left hand, in left-handers - on the right hand.

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The normal pressure of an adult is between 110/70 and 125/85 mm Hg. Art. If a person conducts systematic measurements of pressure and received an indicator of 10 mm Hg. higher or lower than the previous one, this is not a pathology. But with constant significant fluctuations in pressure, you should consult a doctor.

Arterial hypotension: symptoms and treatment

Systematic pressure with an indicator below 100/60 mm Hg. Art. called arterial hypotension.

Most of all, teenagers and young girls are prone to it. The main symptoms of hypotension include:

• dizziness;
• fast fatigue;
• lethargy;
• nausea;
• insomnia;
• cardiopalmus.

In the process of treatment, the specialist must establish the root cause that affects the decrease in pressure.

Reduced arterial pressure though not fraught with such terrible complications, as high, but it is uncomfortable for a person to live with him

Together with the treatment of the underlying disease, drug treatment is prescribed:

1. psychomotor stimulants. These drugs activate nervous system, they stimulate efficiency and relieve lethargy, increase heart rate and increase pressure ("Sindocarb", "Mezokarb").
2. analeptic drugs. Increase blood circulation in the process of excitation of the vasomotor center back section brain. These drugs increase the efficiency and mood of a person ("Cordiamin").
3. Alpha-agonists. They increase vascular tone, cause narrowing of arterioles ("Gutron", "Midodrin").

Each of the described medicines has its own number side effects Therefore, it should be prescribed under the strict supervision of a physician. Hypotension patients should devote time to physical activity and long sleep, it is also recommended cold and hot shower.

Products that increase blood pressure and improve the condition of the body hypotonic:

• coffee;
• strong tea;
• nuts;
• cheeses.

A cup of coffee helps, but be aware of the addictive property of the drink.

Hypertension: manifestations and principles of treatment

Elevated constant blood pressure 139/89 mm Hg. Art. is one of the most common diseases of cardio-vascular system.

Older people with diseases of the heart and blood vessels are most prone to hypertension. But the appearance of elevated blood pressure in people over 30 years of age is not ruled out.

To risk factors for development arterial hypertension include:

• systematic stress;
• excess weight;
• heredity;
• age over 55;
• diabetes;
• elevated cholesterol levels;
• kidney failure;
• constant smoking and alcohol consumption.

Latent course of hypertension or initial stage diseases can be suspected if periodically noted: headaches

In order for the treatment to be effective, in parallel with hypertension, the doctor will treat its root cause. When treating elderly hypertensive patients, it is important that the doctor knows the general condition of the sick patient and his weak sides. They are prescribed medication for the minimum amount side effects, so that the drugs do not affect the work of already diseased organs and do not worsen his health.

Downgrade high blood pressure These drugs will help:

1. Diuretics. They are assigned to remove excess salt and body fluids that contribute to high blood pressure. Potassium-containing diuretics, together with the liquid, do not remove potassium, which is important for the body, and thiazide-type diuretics have a low series side effects on the body ("Aldactone", "Indapamide").
2. Beta blockers. By decreasing the amount of adrenaline, these medicines decrease the heart rate. In its work, adrenaline is interconnected with beta-adrenergic receptors, the work of which is blocked by these medicines (Concor, Vasocardin).
3. calcium antagonists. Such drugs dilate blood vessels and increase blood flow in the body. The decrease in pressure occurs due to inhibition of the flow of calcium ions into the heart and blood vessels of the patient ("Lomir", "Norvask").

Therapeutic measures for hypertension may include both pharmacological and non-pharmacological methods

Pressure in children and adolescents

During the period of growth and puberty, the body of a child and adolescent undergoes active restructuring and changes. Indicator 120/80 mm Hg. Art. refers to a fully formed person, and normal indicators in children and adolescents will be underestimated. So, the pressure is 105/60 mm Hg. Art. considered normal for a child of 6-10 years.

Everything is quite simple. It is one of the main indicators of the activity of the cardiovascular system. Let's look at this issue in more detail.

What is BP?

Blood pressure is the process of squeezing the walls of capillaries, arteries and veins under the influence of blood circulation.

Kinds blood pressure:

• upper, or systolic;
• lower, or diastolic.

When determining the level of blood pressure, both of these values ​​\u200b\u200bmust be taken into account. The units of its measurement remained the very first - millimeters of a mercury column. This is due to the fact that mercury was used in the old devices to determine the level of blood pressure. Therefore, BP looks like in the following way: upper blood pressure (for example, 130) / lower blood pressure (for example, 70) mm Hg. Art.

Circumstances that directly affect the range of blood pressure include:

• the level of strength of contractions performed by the heart;
• the proportion of blood pushed out by the heart during each contraction;
• wall resistance blood vessels which turns out to be a blood stream;
• the amount of blood circulating in the body;
• pressure fluctuations in chest that are caused by the respiratory process.

Blood pressure levels can change throughout the day and with age. But for most healthy people characterized by stable blood pressure.

Definition of types of blood pressure

Systolic (upper) blood pressure is a characteristic general condition veins, capillaries, arteries, as well as their tone, which is caused by contraction of the heart muscle. It is responsible for the work of the heart, namely, with what force the latter is able to expel blood.

Thus, the level of upper pressure depends on the strength and speed with which heart contractions occur.

It is unreasonable to assert that arterial and cardiac pressure is one and the same concept, since the aorta also participates in its formation.

The lower characterizes the activity of blood vessels. In other words, this is the level of blood pressure at the moment when the heart is maximally relaxed.

Lower pressure is formed as a result of contraction peripheral arteries, through which blood enters the organs and tissues of the body. Therefore, the state of blood vessels is responsible for the level of blood pressure - their tone and elasticity.

How to know the level of blood pressure?

You can find out your blood pressure level using a special device called a blood pressure monitor. This can be done both at the doctor's (or nurse's) and at home, having previously bought the device at the pharmacy.

Distinguish the following types tonometers:

• automatic;
• semi-automatic;
• mechanical.

A mechanical tonometer consists of a cuff, a pressure gauge or display, a pear for pumping air and a stethoscope. Principle of operation: put the cuff on your arm, put a stethoscope under it (while you should hear the pulse), inflate the cuff with air until it stops, and then start to lower it gradually, unscrewing the wheel on the pear. At some point, you will clearly hear pulsating sounds in the stethoscope headphones, then they will stop. These two marks are the upper and lower blood pressure.

Consists of a cuff, an electronic display and a pear. Principle of operation: put on the cuff, pump up the air to the maximum with a pear, then let it out. The electronic display shows the upper and lower values ​​of blood pressure and the number of beats per minute - the pulse.

The automatic blood pressure monitor consists of a cuff, an electronic display and a compressor that performs inflation and deflation manipulations. Principle of operation: put on the cuff, start the device and wait for the result.

It is generally accepted that a mechanical tonometer gives the most exact result. It's also more affordable. At the same time, automatic and semi-automatic blood pressure monitors remain the most convenient to use. Such models are especially suitable for older people. Moreover, some types have the function of voice notification of pressure indicators.

It is worth measuring blood pressure indicators no earlier than thirty minutes after any physical exertion (even minor ones) and one hour after drinking coffee and alcohol. Before the measurement process itself, you need to sit quietly for a couple of minutes, catch your breath.

Blood pressure - the norm by age

Each person has an individual which may not be associated with any diseases.

The level of blood pressure is determined by a number of factors that are of particular importance:

• age and gender of the person;
• personal characteristics;
• life style;
• lifestyle features, preferred type of vacation, and so on).

Blood pressure also tends to rise with unusual physical activity and emotional stress. And if a person constantly performs physical exercise(for example, an athlete), then the level of blood pressure may also change both for time and for a long period. For example, when a person in stressful condition, then his blood pressure can rise to thirty mm Hg. Art. from the norm.

However, there are still certain limits of normal blood pressure. And even every ten points of deviation from the norm indicate a violation of the body.

Blood pressure - the norm by age

Age	The upper level of blood pressure, mm Hg. Art.	The lower level of blood pressure, mm Hg. Art.
1 - 10 years
	from 95 to 110
16 - 20 years old	from 110 to 120
21 - 40 years old	from 120 to 130
41 - 60 years old
61 - 70 years old	from 140 to 147
Over 71 years old

You can also calculate the individual value of blood pressure using the following formulas:

1. For men:

• upper blood pressure = 109 + (0.5 * number full years) + (0.1 * weight in kg);
• lower BP \u003d 74 + (0.1 * number of full years) + (0.15 * weight in kg).

2. For women:

• upper BP \u003d 102 + (0.7 * number of full years) + 0.15 * weight in kg);
• lower blood pressure \u003d 74 + (0.2 * number of full years) + (0.1 * weight in kg).

The resulting value is rounded to an integer according to the rules of arithmetic. That is, if it turned out to be 120.5, then when rounded it will be 121.

Elevated blood pressure

High blood pressure is high level at least one of the indicators (lower or upper). It is necessary to judge the degree of its overestimation, taking into account both indicators.

Regardless of whether the lower blood pressure is high or upper, it is a disease. And it's called hypertension.

There are three degrees of the disease:

• the first - GARDEN 140-160 / DBP 90-100;
• the second - SAD 161-180 / DBP 101-110;
• the third - GARDEN 181 and more / DBP 111 and more.

It is worth talking about hypertension when there is a high level of blood pressure values ​​for a long period.

According to statistics, an overestimated indicator of systolic pressure is most often observed in women, and diastolic - in men and the elderly.

Symptoms of high blood pressure can be:

• decrease in working capacity;
• appearance of fatigue;
• frequent feelings of weakness;
• morning pain in the back of the head;
• frequent dizziness;
• occurrence of bleeding from the nose;
• noise in ears;
• decreased visual acuity;
• appearance at the end of the day.

Causes of high blood pressure

If lower arterial, then most likely this is one of the symptoms of the disease thyroid gland, kidneys, adrenal glands, which began to produce renin in large quantities. It, in turn, increases the tone of the muscles of the blood vessels.

Elevated lower blood pressure is fraught with the development of more more serious illnesses.

high top pressure indicates too frequent contractions of the heart.

A jump in blood pressure can be caused by a number of reasons. This is for example:

• vasoconstriction due to atherosclerosis;
• overweight;
• diabetes;
• stressful situations;
• malnutrition;
• excessive consumption of alcohol, strong coffee and tea;
• smoking;
• lack of physical activity;
• frequent weather changes;
• some diseases.

What is low BP?

Low blood pressure is vegetovascular dystonia or hypotension.

What happens with hypotension? When the heart contracts, blood enters the vessels. They expand and then gradually narrow. Thus, the vessels help the blood to move further along circulatory system. The pressure is normal. For a number of reasons, vascular tone may decrease. They will remain expanded. Then there is not enough resistance for the movement of blood, because of which the pressure drops.

The level of blood pressure in hypotension: upper - 100 or less, lower - 60 or less.

If the pressure drops sharply, then the blood supply to the brain is limited. And this is fraught with such consequences as dizziness and fainting.

Symptoms may be:

• increased fatigue and lethargy;
• darkening in the eyes;
• frequent shortness of breath;
• cold feeling in hands and feet;
• hypersensitivity to loud sounds and bright light
• muscle weakness;
• motion sickness in transport;
• frequent headaches.

What is the reason for low blood pressure?

Poor joint tone and low blood pressure (hypotension) can be present from birth. But more often the culprits reduced pressure become:

• Severe fatigue and stress. Congestion at work and at home, stress and lack of sleep cause a decrease in vascular tone.
• Heat and stuffiness. When you sweat, it leaves the body a large number of liquids. For the sake of maintaining water balance it pumps water out of the blood that flows through the veins and arteries. Its volume decreases, vascular tone decreases. The pressure drops.
• Taking medication. Heart drugs, antibiotics, antispasmodics and painkillers can “drop” the pressure.
• emergence allergic reactions anything with possible anaphylactic shock.

If you have not had hypotension before, do not leave unpleasant symptoms without attention. They can be dangerous "bells" of tuberculosis, stomach ulcers, complications after a concussion and other diseases. Contact a therapist.

What to do to normalize the pressure?

These tips will help you feel whole hearty day if you are hypotonic.

1. Don't rush to get out of bed. Wake up - do a little warm-up lying down. Move your arms and legs. Then sit down and stand up slowly. Perform actions without sudden movements. they can cause fainting.
2. Take a contrast shower in the morning for 5 minutes. Alternate water - a minute warm, a minute cool. This will help to cheer up and is good for blood vessels.
3. A good cup of coffee! But only natural tart drink will raise the pressure. Drink no more than 1-2 cups per day. If you have heart problems, drink coffee instead green tea. It invigorates no worse than coffee, but does not harm the heart.
4. Sign up for a pool. Go at least once a week. Swimming improves vascular tone.
5. Buy a tincture of ginseng. This natural "energy" gives tone to the body. Dissolve 20 drops of tincture in ¼ cup of water. Drink half an hour before meals.
6. Eat sweets. As soon as you feel weak - eat ½ teaspoon of honey or a little dark chocolate. Sweets will drive away fatigue and drowsiness.
7. Drink clean water. Daily 2 liters of pure and non-carbonated. This will help maintain pressure on normal level. If you have diseased heart and kidneys drinking regimen must be prescribed by a doctor.
8. get enough sleep. A rested body will work as it should. Sleep at least 7-8 hours a day.
9. Get a massage. According to experts oriental medicine, there are special points on the body. By acting on them, you can improve your well-being. Pressure is controlled by the point between the nose and upper lip. Gently massage it with your finger for 2 minutes in a clockwise direction. Do this when you feel weak.

First aid for hypotension and hypertension

If you feel dizzy severe weakness, tinnitus, call an ambulance. In the meantime, the doctors go, act:

1. Open the collar of your clothes. The neck and chest should be free.
2. Lie down. Lower your head down. Place a small pillow under your feet.
3. Smell ammonia. If it is not available, use table vinegar.
4. Have some tea. Definitely strong and sweet.

If you feel close hypertensive crisis, it is also necessary to call doctors. In general, this disease should always be supported preventive treatment. As first aid measures, you can resort to the following actions:

1. Organize foot bath With hot water, in which mustard was previously added. An alternative would be to overlay mustard compresses on the region of the heart, neck and calves.
2. Lightly bind the right, and then the left arm and leg for half an hour each side. When the tourniquet is applied, a pulse should be felt.
3. Have a drink from chokeberry. It can be wine, compote, juice. Or eat jam from this berry.

To reduce the risk of occurrence and development of hypotension and hypertension, you should adhere to a regimen healthy eating, prevent the appearance excess weight, exclude harmful products from the list, move more.

Pressure should be measured from time to time. When observing a trend of high or low blood pressure, it is recommended to consult a doctor to determine the causes and prescribe treatment. Prescribed therapies may include methods to normalize blood pressure, such as taking special medications and herbal infusions diet, exercise, and so on.

Nobody likes to be under pressure. And it doesn't matter which one. Queen also sang about this along with David Bowie in their famous single "Under pressure". What is pressure? How to understand pressure? In what it is measured, by what instruments and methods, where it is directed and what it presses on. The answers to these and other questions - in our article about pressure in physics and not only.

If the teacher puts pressure on you by asking tricky problems, we will make sure that you can answer them correctly. After all, understanding the essence of things is the key to success! So what is pressure in physics?

By definition:

Pressure is a scalar physical quantity equal to the force acting per unit area of ​​the surface.

In the international system, the SI is measured in Pascals and is marked with the letter p . Pressure unit - 1 Pascal. Russian designation - Pa, international - Pa.

According to the definition, to find pressure, you need to divide the force by the area.

Any liquid or gas placed in a vessel exerts pressure on the walls of the vessel. For example, borscht in a saucepan acts on its bottom and walls with some pressure. Formula for determining fluid pressure:

where g is the acceleration of free fall in the gravitational field of the earth, h- the height of the borscht column in the pan, Greek letter "ro"- the density of borscht.

The most commonly used instrument for measuring pressure is the barometer. But what is pressure measured in? In addition to pascal, there are other off-system units of measurement:

• atmosphere;
• millimeter of mercury;
• millimeter of water column;
• meter of water column;
• kilogram-force.

Depending on the context, different off-system units are used.

For example, when you listen to or read the weather forecast, there is no question of Pascals. They talk about millimeters of mercury. One millimeter of mercury is 133 Pascal. If you drive, you probably know that normal pressure in the wheels of a car - about two atmospheres.

Atmosphere pressure

The atmosphere is a gas, more precisely, a mixture of gases that is held near the Earth due to gravity. The atmosphere passes into interplanetary space gradually, and its height is approximately 100 kilometers.

How to understand the expression "atmospheric pressure"? Above every square meter of the earth's surface is a hundred-kilometer column of gas. Of course, the air is transparent and pleasant, but it has a mass that presses on the surface of the earth. This is atmospheric pressure.

Normal atmospheric pressure is considered to be equal to 101325 Pa. This is the pressure at sea level at 0 degrees Celsius. Celsius. The same pressure at the same temperature is exerted on its base by a column of mercury with a height 766 millimeters.

The higher the altitude, the lower the atmospheric pressure. For example, on top of a mountain Chomolungma it is only one-fourth of normal atmospheric pressure.

Arterial pressure

Another example where we face pressure in Everyday life is a measurement of blood pressure.

Blood pressure is blood pressure, i.e. The pressure that blood exerts on the walls of blood vessels, in this case arteries.

If you have measured your blood pressure and you have it 120 on the 80 , then all is well. If a 90 on the 50 or 240 on the 180 , then it will definitely not be interesting for you to figure out what this pressure is measured in and what it generally means.

However, the question arises: 120 on the 80 what exactly? Pascals, millimeters of mercury, atmospheres or some other units of measurement?

Blood pressure is measured in millimeters of mercury. It determines the excess pressure of the fluid in the circulatory system over atmospheric pressure.

Blood exerts pressure on the vessels and thereby compensates for the effect of atmospheric pressure. Otherwise, we would simply be crushed by a huge mass of air above us.

But why are there two digits in the blood pressure measurement?

By the way! For our readers there is now a 10% discount on

The fact is that the blood moves in the vessels not evenly, but in jolts. The first digit (120) is called systolic pressure. This is the pressure on the walls of blood vessels at the time of contraction of the heart muscle, its value is the largest. The second digit (80) defines smallest value and called diastolic pressure.

When measuring, the values ​​​​of systolic and diastolic pressures are recorded. For example, for a healthy person, a typical blood pressure value is 120 to 80 millimeters of mercury. It means that systolic pressure equals 120 mm. rt. Art., and diastolic - 80 mm Hg. Art. The difference between systolic and diastolic pressure is called pulse pressure.

physical vacuum

Vacuum is the absence of pressure. More precisely, its almost complete absence. Absolute vacuum is an approximation, like an ideal gas in thermodynamics and a material point in mechanics.

Depending on the concentration of the substance, low, medium and high vacuum are distinguished. The best approximation to the physical vacuum is space, in which the concentration of molecules and pressure are minimal.

Pressure is the main thermodynamic parameter of the state of the system. It is possible to determine the pressure of air or another gas not only by instruments, but also using equations, formulas and laws of thermodynamics. And if you don’t have time to figure it out, the student service will help you solve any problem of determining pressure.

Pressure This term has other meanings, see Pressure (meanings). Dimension Units SI CGS

Pressure- a physical quantity numerically equal to the force F acting per unit surface area S perpendicular to this surface. At a given point, pressure is defined as the ratio of the normal component of the force acting on a small surface element to its area:

The average pressure over the entire surface is the ratio of the force to the surface area:

Pressure characterizes the state of a continuous medium and is the diagonal component of the stress tensor. In the simplest case of an isotropic equilibrium stationary medium, the pressure does not depend on the orientation. Pressure can also be considered a measure of the potential energy stored in a continuous medium per unit volume and measured in units of energy per unit volume.

The pressure is intense physical quantity. Pressure in the SI system is measured in pascals (newtons per square meter, or, equivalently, joules per square meter). cubic meter); The following units are also used:

• Technical atmosphere (ata - absolute, ati - excess)
• physical atmosphere
• millimeter of mercury
• Water column meter
• inch of mercury
• Pound-force per square inch

Pressure units Pascal
(Pa, Pa) Bar



(mmHg,mmHg, Torr, Torr) Water column meter
(m water column, m H 2 O) Pound-force
per sq. inch
(psi) 1 Pa 1 bar 1 atm 1 atm 1 mmHg 1 m water Art. 1psi

Measurement of the pressure of gases and liquids is carried out using pressure gauges, differential pressure gauges, vacuum gauges, pressure sensors, atmospheric pressure - barometers, blood pressure - tonometers.

see also

• Arterial pressure
• Atmosphere pressure
• barometric formula
• Vacuum
• light pressure
• Diffusion pressure
• Bernoulli's law
• Pascal's law
• Sound pressure and sound pressure
• Pressure measurement
• critical pressure
• pressure gauge
• Mechanical stress
• Molecular Kinetic Theory
• Head (hydrodynamics)
• Oncotic pressure
• Osmotic pressure
• Partial pressure
• State equation
• Materials science of ultrahigh pressures

Notes

1. English E.R. Cohen et al., "Quantities, Units and Symbols in Physical Chemistry", IUPAC Green Book, 3rd Edition, 2nd Printing, IUPAC & RSC Publishing, Cambridge (2008). - p. fourteen.

Hi all!

Weather Seasons Precipitation Forecast and Clouds Humidity (absolute and relative) Pressure Air temperature Wind direction Wind Thunderstorm Tornado Hurricane Storm Categories:

• Physical quantities alphabetically
• Pressure units

Pressure units

• Pascal (newton per square meter)
• Millimeter of mercury (torr)
• Micron of mercury (10−3 Torr)
• Millimeter of water (or water) column
• Atmosphere
  • physical atmosphere
  • Atmosphere technical
• Kilogram-force square centimeter, kilogram-force per square meter
• Dyne per square centimeter (barium)
• Pound-force per square inch (psi)
• Pieza (ton-force per square meter, walls per square meter)

Pressure units Pascal
(Pa, Pa) Bar
(bar) Technical atmosphere
(at, at) Physical atmosphere
(atm, atm) Millimeter of mercury
(mm Hg, mm Hg, Torr, Torr) Water column meter
(m water column, m H 2 O) Pound-force
per sq. inch
(psi) 1 Pa 1 bar 1 atm 1 atm 1 mmHg Art. 1 m water Art. 1psi

Links

• Converting pressure units to each other
• Conversion table for pressure units.

Blood pressure - what is it? What blood pressure is considered normal

What does blood pressure mean? Everything is quite simple. It is one of the main indicators of the activity of the cardiovascular system. Let's look at this issue in more detail.

What is BP?

Blood pressure is the process of squeezing the walls of capillaries, arteries and veins under the influence of blood circulation.

Types of blood pressure:

• upper, or systolic;
• lower, or diastolic.

When determining the level of blood pressure, both of these values ​​\u200b\u200bmust be taken into account. The units of its measurement remained the very first - millimeters of a mercury column. This is due to the fact that mercury was used in the old devices to determine the level of blood pressure. Therefore, the BP indicator looks like this: upper blood pressure (for example, 130) / lower blood pressure (for example, 70) mm Hg. Art.

Circumstances that directly affect the range of blood pressure include:

• the level of strength of contractions performed by the heart;
• the proportion of blood pushed out by the heart during each contraction;
• resistance of the walls of blood vessels, which is the flow of blood;
• the amount of blood circulating in the body;
• fluctuations in pressure in the chest, which are caused by the respiratory process.

Blood pressure levels can change throughout the day and with age. But for most healthy people, a stable blood pressure indicator is characteristic.

Definition of types of blood pressure

Systolic (upper) blood pressure is a characteristic of the general condition of the veins, capillaries, arteries, as well as their tone, which is caused by contraction of the heart muscle. It is responsible for the work of the heart, namely, with what force the latter is able to expel blood.

Thus, the level of upper pressure depends on the strength and speed with which heart contractions occur.

It is unreasonable to assert that arterial and cardiac pressure is the same concept, since the aorta also participates in its formation.

Lower (diastolic) pressure characterizes the activity of blood vessels. In other words, this is the level of blood pressure at the moment when the heart is maximally relaxed.

Lower pressure is formed as a result of the contraction of peripheral arteries, through which blood enters the organs and tissues of the body. Therefore, the state of blood vessels is responsible for the level of blood pressure - their tone and elasticity.

How to know the level of blood pressure?

You can find out your blood pressure level using a special device called a blood pressure monitor. This can be done both at the doctor's (or nurse's) and at home, having previously bought the device at the pharmacy.

There are the following types of tonometers:

• automatic;
• semi-automatic;
• mechanical.

A mechanical tonometer consists of a cuff, a pressure gauge or display, a pear for pumping air and a stethoscope. Principle of operation: put the cuff on your arm, put a stethoscope under it (while you should hear the pulse), inflate the cuff with air until it stops, and then start to lower it gradually, unscrewing the wheel on the pear. At some point, you will clearly hear pulsating sounds in the stethoscope headphones, then they will stop. These two marks are the upper and lower blood pressure.

The semi-automatic tonometer consists of a cuff, an electronic display and a pear. Principle of operation: put on the cuff, pump up the air to the maximum with a pear, then let it out. The electronic display shows the upper and lower values ​​of blood pressure and the number of beats per minute - the pulse.

The automatic blood pressure monitor consists of a cuff, an electronic display and a compressor that performs inflation and deflation manipulations. Principle of operation: put on the cuff, start the device and wait for the result.

It is generally accepted that a mechanical tonometer gives the most accurate result. It's also more affordable. At the same time, automatic and semi-automatic blood pressure monitors remain the most convenient to use. Such models are especially suitable for older people. Moreover, some types have the function of voice notification of pressure indicators.

It is worth measuring blood pressure indicators no earlier than thirty minutes after any physical exertion (even minor ones) and one hour after drinking coffee and alcohol. Before the measurement process itself, you need to sit quietly for a couple of minutes, catch your breath.

Blood pressure - the norm by age

Every person has individual norm BP, which may not be associated with any disease.

The level of blood pressure is determined by a number of factors that are of particular importance:

• age and gender of the person;
• personal characteristics;
• life style;
• lifestyle features labor activity, preferred type of vacation, and so on).

Even blood pressure tends to rise when performing unusual physical exertion and emotional stress. And if a person constantly performs physical activity (for example, an athlete), then the level of blood pressure can also change both for a while and for a long period. For example, when a person is under stress, his blood pressure can rise to thirty mm Hg. Art. from the norm.

However, there are still certain limits of normal blood pressure. And even every ten points of deviation from the norm indicate a violation of the body.

Blood pressure - the norm by age

You can also calculate the individual value of blood pressure using the following formulas:

1. For men:

• upper BP \u003d 109 + (0.5 * number of full years) + (0.1 * weight in kg);
• lower BP \u003d 74 + (0.1 * number of full years) + (0.15 * weight in kg).

2. For women:

• upper BP \u003d 102 + (0.7 * number of full years) + 0.15 * weight in kg);
• lower blood pressure \u003d 74 + (0.2 * number of full years) + (0.1 * weight in kg).

The resulting value is rounded to an integer according to the rules of arithmetic. That is, if it turned out to be 120.5, then when rounded it will be 121.

Elevated blood pressure

High blood pressure is a high level of at least one of the indicators (lower or upper). It is necessary to judge the degree of its overestimation, taking into account both indicators.

Regardless of whether the lower blood pressure is high or upper, it is a disease. And it's called hypertension.

There are three degrees of the disease:

• the first - SAD 140-160 / DBP 90-100;
• the second - SAD 161-180 / DBP 101-110;
• the third - GARDEN 181 and more / DBP 111 and more.

It is worth talking about hypertension when there is a high level of blood pressure values ​​for a long period.

According to statistics, an overestimated indicator of systolic pressure is most often observed in women, and diastolic - in men and the elderly.

Symptoms of high blood pressure can be:

• decrease in working capacity;
• appearance of fatigue;
• frequent feelings of weakness;
• morning pain in the back of the head;
• frequent dizziness;
• occurrence of bleeding from the nose;
• noise in ears;
• decreased visual acuity;
• the appearance of swelling of the legs at the end of the day.

Causes of high blood pressure

If the lower blood pressure is high, then most likely this is one of the symptoms of a disease of the thyroid gland, kidneys, adrenal glands, which began to produce renin in large quantities. It, in turn, increases the tone of the muscles of the blood vessels.

Elevated lower blood pressure is fraught with the development of even more serious diseases.

High upper pressure indicates too frequent contractions of the heart.

A jump in blood pressure can be caused by a number of reasons. This is for example:

• vasoconstriction due to atherosclerosis;
• overweight;
• diabetes;
• stressful situations;
• malnutrition;
• excessive consumption of alcohol, strong coffee and tea;
• smoking;
• lack of physical activity;
• frequent weather changes;
• some diseases.

What is low BP?

Low blood pressure is vegetovascular dystonia or hypotension.

What happens with hypotension? When the heart contracts, blood enters the vessels. They expand and then gradually narrow. Thus, the vessels help the blood to move further through the circulatory system. The pressure is normal. For a number of reasons, vascular tone may decrease. They will remain expanded. Then there is not enough resistance for the movement of blood, because of which the pressure drops.

The level of blood pressure in hypotension: upper - 100 or less, lower - 60 or less.

If the pressure drops sharply, then the blood supply to the brain is limited. And this is fraught with such consequences as dizziness and fainting.

Symptoms of low blood pressure may include:

• increased fatigue and lethargy;
• darkening in the eyes;
• frequent shortness of breath;
• cold feeling in hands and feet;
• hypersensitivity to loud sounds and bright lights;
• muscle weakness;
• motion sickness in transport;
• frequent headaches.

What is the reason for low blood pressure?

Poor joint tone and low blood pressure (hypotension) can be present from birth. But more often the culprits of low blood pressure are:

• Severe fatigue and stress. Congestion at work and at home, stress and lack of sleep cause a decrease in vascular tone.
• Heat and stuffiness. When you sweat, a large amount of fluid comes out of the body. In order to maintain water balance, it pumps water out of the blood that flows through the veins and arteries. Its volume decreases, vascular tone decreases. The pressure drops.
• Taking medication. Heart drugs, antibiotics, antispasmodics and painkillers can “drop” the pressure.
• The occurrence of allergic reactions anything with possible anaphylactic shock.

If you have not had hypotension before, do not leave unpleasant symptoms unattended. They can be dangerous "bells" of tuberculosis, stomach ulcers, complications after a concussion and other diseases. Contact a therapist.

What to do to normalize the pressure?

These tips will help you feel alert all day if you are hypotensive.

1. Don't rush to get out of bed. Wake up - do a little warm-up lying down. Move your arms and legs. Then sit down and stand up slowly. Perform actions without sudden movements. they can cause fainting.
2. Take a contrast shower in the morning for 5 minutes. Alternate water - a minute warm, a minute cool. This will help to cheer up and is good for blood vessels.
3. A good cup of coffee! But only a natural tart drink will raise the pressure. Drink no more than 1-2 cups per day. If you have heart problems, drink green tea instead of coffee. It invigorates no worse than coffee, but does not harm the heart.
4. Sign up for a pool. Go at least once a week. Swimming improves vascular tone.
5. Buy a tincture of ginseng. This natural "energy" gives tone to the body. Dissolve 20 drops of tincture in ¼ cup of water. Drink half an hour before meals.
6. Eat sweets. As soon as you feel weak - eat ½ teaspoon of honey or a little dark chocolate. Sweets will drive away fatigue and drowsiness.
7. Drink clean water. Daily 2 liters of pure and non-carbonated. This will help keep your blood pressure at a normal level. If you have a sick heart and kidneys, a doctor should prescribe a drinking regimen.
8. get enough sleep. A rested body will work as it should. Sleep at least 7-8 hours a day.
9. Get a massage. According to experts in oriental medicine, there are special points on the body. By acting on them, you can improve your well-being. The point that is located between the nose and the upper lip is responsible for the pressure. Gently massage it with your finger for 2 minutes in a clockwise direction. Do this when you feel weak.

First aid for hypotension and hypertension

If you feel dizzy, severe weakness, tinnitus, call an ambulance. In the meantime, the doctors go, act:

1. Open the collar of your clothes. The neck and chest should be free.
2. Lie down. Lower your head down. Place a small pillow under your feet.
3. Smell ammonia. If it is not available, use table vinegar.
4. Have some tea. Definitely strong and sweet.

If you feel the approach of a hypertensive crisis, then you also need to call the doctors. In general, this disease should always be supported by preventive treatment. As first aid measures, you can resort to the following actions:

1. Organize a foot bath with hot water, which is pre-added with mustard. An alternative would be to apply mustard compresses to the area of ​​the heart, back of the head and calves.
2. Lightly bind the right, and then the left arm and leg for half an hour each side. When the tourniquet is applied, a pulse should be felt.
3. Drink a drink from chokeberry. It can be wine, compote, juice. Or eat jam from this berry.

To reduce the risk of occurrence and development of hypotension and hypertension, you should adhere to a healthy diet, prevent the appearance of excess weight, exclude harmful products from the list, and move more.

Pressure should be measured from time to time. When observing a trend of high or low blood pressure, it is recommended to consult a doctor to determine the causes and prescribe treatment. Prescribed therapy may include methods to normalize blood pressure, such as taking special medicines and herbal infusions, dieting, performing a set of exercises, and so on.

What is atmospheric pressure, definition. Physics Grade 7

The atmosphere extends several thousand kilometers above our planet. Due to the action of gravity, the upper layers of air, like water in the ocean, compress the lower layers, as a result of which the earth's surface and the bodies on it experience pressure from the entire thickness of the air.
Atmospheric pressure is the pressure exerted by the Earth's atmosphere on all objects on it.

Vyatheslav nasyrov

Atmospheric pressure - the pressure of the atmosphere on all objects in it and the Earth's surface. Atmospheric pressure is created by the gravitational attraction of air to the Earth.
In 1643, Evangelista Torricelli showed that air has weight. Together with V. Viviani, Torricelli conducted the first experiment on measuring atmospheric pressure, inventing the Torricelli tube (the first mercury barometer), a glass tube in which there is no air. In such a tube, mercury rises to a height of about 760 mm.
On the earth's surface, atmospheric pressure varies from place to place and over time. Especially important are the non-periodic changes in atmospheric pressure that determine the weather, associated with the emergence, development and destruction of slowly moving high-pressure areas (anticyclones) and relatively fast moving huge eddies (cyclones), in which low pressure prevails. There were fluctuations in atmospheric pressure at sea level within 684 - 809 mm Hg. Art.
Normal atmospheric pressure is a pressure of 760 mm Hg. Art. (101 325 Pa).
Atmospheric pressure decreases as altitude increases, since it is created only by the overlying layer of the atmosphere. The dependence of pressure on height is described by the so-called. barometric formula. The height to which one must rise or fall in order for the pressure to change by 1 hPa is called the baric (barometric) step. Near the earth's surface at a pressure of 1000 hPa and a temperature of 0 °C, it is 8 m/hPa. With an increase in temperature and an increase in altitude above sea level, it increases, that is, it is directly proportional to temperature and inversely proportional to pressure. The reciprocal of the baric step is the vertical baric gradient, i.e., the change in pressure when raising or lowering 100 meters. At a temperature of 0 °C and a pressure of 1000 hPa, it is equal to 12.5 hPa.
On maps, pressure is shown using isobars - lines connecting points with the same surface atmospheric pressure, necessarily reduced to sea level. Atmospheric pressure is measured with a barometer.

Ivan Ivanov

We do not notice the air, because we all live in it. It's hard to imagine, but air has weight in the same way as all bodies on Earth. This is so because gravity acts on it. Air can even be weighed on a scale by placing it in a glass ball. Paragraph forty-two describes how to do this. We do not notice the weight of the air, nature arranged it that way.
Air is held near the Earth by gravity. He does not fly into space thanks to her. The multi-kilometer air shell around the Earth is called the atmosphere. Of course, the atmosphere presses on us and on all other bodies. The pressure of the atmosphere is called atmospheric pressure.
We do not notice it, because the pressure we have inside is the same as the air pressure outside. In the textbook you will find a description of several experiments proving that there is atmospheric pressure. And, of course, try some of them to repeat. Or maybe you can come up with your own or peep on the Internet to show in the lesson, to surprise classmates. There are very entertaining experiments about atmospheric pressure.

What is blood pressure definition?

Blood pressure is the pressure of blood on the walls of blood vessels - veins, arteries and capillaries. Blood pressure is necessary in order to ensure that blood can move through the blood vessels.
The value of arterial pressure (sometimes abbreviated as blood pressure) is determined by the strength of heart contractions, the amount of blood that is ejected into the vessels with each contraction of the heart, the resistance that the walls of blood vessels provide to blood flow and, to a lesser extent, the number of heartbeats per unit time. In addition, the value of blood pressure depends on the amount of blood circulating in the circulatory system, its viscosity. Fluctuations in pressure in the abdominal and chest cavities, Related respiratory movements, and other factors.
When blood is forced into the heart, the pressure in it increases until the moment when blood is ejected from the heart into the vessels. These two phases - pumping blood into the heart and pushing it into the vessels - make up, speaking medical language, systole of the heart. Then the heart relaxes, and after a kind of “rest”, it begins to fill with blood again. This stage is called diastole of the heart. Accordingly, the pressure in the vessels has two extreme values: the maximum - systolic, and the minimum - diastolic. And the difference in the value of systolic and diastolic pressure, more precisely, fluctuations in their values, is called pulse pressure. The norm of systolic pressure in large arteries is 110-130 mm Hg, and diastolic pressure is about 90 mm Hg. in the aorta and about 70 mm Hg. in large arteries. These are the same indicators that are known to us under the name of upper and lower pressure.

Muslimgauze

Blood pressure is the pressure that blood exerts on the walls of the blood vessels through which it travels. The value of blood pressure is determined by the strength of heart contractions, the amount of blood and the resistance of blood vessels.
Most high pressure observed at the time of ejection of blood into the aorta; the minimum - at the moment when the blood reaches the hollow veins. Distinguish between upper (systolic) pressure and lower (diastolic) pressure.