home Zoology Partial pressure difference. Partial pressure of carbon dioxide. Partial pressure of oxygen and carbon dioxide in the human body in terrestrial conditions

Partial pressure difference. Partial pressure of carbon dioxide. Partial pressure of oxygen and carbon dioxide in the human body in terrestrial conditions

Arterial hypertension is a chronic disease that affects a large number of modern people.

The difficulty is that many patients neglect preventive measures and a healthy lifestyle.

It is necessary to know what arterial hypertension is in order to start therapeutic procedures in a timely manner, preventing large-scale complications fraught with death.

The vascular system of the body is similar to a tree, where the aorta is a trunk that branches into arteries, which are subdivided into small branches - arterioles.

Their task is to carry blood to the capillaries that supply nutrients and oxygen to every cell of the human body. After the transfer of oxygen to the blood, they again return to the heart through the venous vessels.

In order for blood to flow through the system of veins and arteries, you need to expend a certain amount of energy. The force acting on the walls of blood vessels during the flow of blood is pressure.

The pressure depends on the functioning of the heart and on the arterioles, which are able to relax if you need to lower blood pressure, or contract if you need to increase it.

Arterial hypertension is a condition that is determined by a persistent increase in systolic pressure up to 140 mm Hg. st and more; and diastolic pressure up to 90 mm Hg. Art. and more.

There are such periods of changes in blood pressure:

drops from 1 am to 5 am,
rises from 6 to 8 in the morning,
drops from 23:00 to 00:00.

Pressure changes with age:

indicators in children are 70/50 mm Hg. Art.,
rates in the elderly are over 120/80.

Causes of arterial hypertension

In many cases, it is not possible to understand how arterial hypertension arose. In this case, we speak of primary essential hypertension. Some doctors believe that the stimulating factors of primary hypertension are:

accumulation of salt in the kidneys,
the presence of vasoconstrictors in the blood,
hormonal imbalance.

Approximately 10% of people develop severe hypertension due to the use of certain drugs or the development of another disease. Such arterial hypertension is called secondary hypertension.

Allocate the most common causes hypertension:

kidney disease,
renovascular hypertension,
adrenal tumor,
pheochromocytoma,
Side effects of drugs
Increased blood pressure during pregnancy.

If the kidneys retain a lot of salt, then the volume of fluid in the body increases. As a result, blood pressure and volume increase. The kidneys also produce the enzyme renin, which plays a key role in determining blood pressure readings.

Renin also increases the production of aldosterone, a hormone responsible for the reabsorption of water and salt.

Severe renovascular hypertension is quite rare, it affects the following groups of people:

elderly people,
smokers,
Small children.

Renovascular hypertension is diagnosed by injecting a contrast agent into an artery or vein and then examining blood flow in the kidneys with x-rays.

The adrenal glands are two glands that secrete many hormones, including aldosterone, located at the top of each kidney. Aldosterone, produced by the adrenal glands, regulates the salt and water balance in the body.

In extremely rare cases, an adrenal tumor provokes an increase in the production of aldosterone, which contributes to the retention of water and salt in the body, thereby increasing pressure. Such arterial hypertension most often affects young women. There are additional symptoms:

intense thirst,
profuse urination.

Another rare type of hypertension is pheochromycytoma, which is caused by another type of adrenal tumor. At the same time, more adrenaline hormone is produced in the pancreas.

Adrenaline is a hormone that helps the body respond fully to stressful situations. This hormone has the following properties:

speeds up the heart rate
increases the pressure
promotes blood transport to the muscles of the lower extremities.

In pheochromocytoma, adrenaline causes:

frequent heartbeat,
shiver,
heat.

Certain drugs and substances can increase blood pressure, such as:

steroids,
antipyretics,
glyceric acid.

Symptoms of arterial hypertension

As you know, arterial hypertension has the second name "silent killer", since its symptoms do not manifest themselves for a long time. Chronic hypertension is one of the main causes of strokes and heart attacks.

Hypertension syndrome has the following symptoms:

Pressive headache that comes on intermittently
Whistling or tinnitus
Fainting and dizziness
"Flies" in the eyes,
Cardiopalmus,
Pressing pains in the region of the heart.

With hypertension, symptoms of the underlying disease can be expressed, especially for kidney disease. Only a doctor can choose drugs for the treatment of hypertension.

Arterial hypertension largely contributes to the hardening of the arteries. Great pressure on the walls of blood vessels leads to their susceptibility to a set of fatty elements. This process is called vascular atherosclerosis.

Over time, the appearance of atherosclerosis provokes a narrowing of the lumen of the arteries and angina pectoris. Narrowing of the arteries of the lower extremities causes the following symptoms:

pain,
stiffness while walking.

Also, due to hypertension, blood clots occur. So, if a blood clot is in the coronary artery, then it leads to a heart attack, and if it is in the carotid artery, to a stroke.

Arterial hypertension, which has not been treated for a long time, often leads to the formation of a dangerous complication - aneurysm. Thus, the wall of the artery protrudes. An aneurysm often ruptures, causing:

internal bleeding
brain bleeding,
stroke.

A persistent increase in blood pressure is the cause of deformation of the arteries. The muscular layer, from which the walls of the arteries are made, begins to thicken, compressing the vessel. This prevents blood from circulating inside the vessel. Over time, thickening of the walls of the vessels of the eyes leads to partial or complete blindness.

The heart is always affected, due to prolonged arterial hypertension. High pressure stimulates the heart muscle to work harder to ensure adequate oxygen saturation of the tissues.

This condition causes the heart to enlarge. In the early stages, the enlarged heart has more strength to optimally pump blood into the arteries at high pressure.

But over time, the enlarged heart muscle can weaken and become stiff, ceasing to fully supply oxygen. The circulatory system must provide a constant supply of nutrients and oxygen to the brain.

If the human body feels a decrease in the amount of blood that enters the brain, then compensatory mechanisms quickly turn on, they increase pressure, and blood from systems and organs is transferred to the brain. The following changes take place:

heart starts beating faster
the blood vessels of the lower extremities and the abdominal region are reduced,
goes to the brain large quantity blood.

As you know, with hypertension, the arteries that supply the brain with oxygen can narrow due to the accumulation of fat-like substances in them. Thus, the risk of strokes increases.

If the arteries of the brain are clogged for a short time, then there is a break in the blood supply to a separate part of the brain. This phenomenon in medicine is called a microstroke.

Even if the condition lasts only a minute, it requires immediate medical attention. If treatment is not performed, this is fraught with the development of a full-fledged stroke. Repetitive microstrokes lead to a weakening of brain function. This is how dementia develops in people with hypertension.

Each kidney is made up of millions of tiny filters called nephrons. Every day, over one and a half thousand liters of blood passes through the kidneys, where waste and toxins are filtered and excreted in the urine. Useful substances go into the bloodstream.

High blood pressure makes the kidneys work harder. In addition, damage to the small vessels within the nephrons reduces the volume of filtered blood. After some time, this leads to a reduction in the filtering function of the kidneys.

Thus, the protein is excreted in the urine before being returned to the bloodstream. Waste products that need to be excreted can enter the bloodstream. This process leads to uremia, and then to kidney failure, which requires constant dialysis and blood purification.

As mentioned earlier, at the bottom of the eyeball there are a large number of blood vessels that are very sensitive to increased blood pressure. After several years of hypertension, the process of destruction of the eye retina can begin. Deformation may be due to:

accumulation of cholesterol in blood vessels
insufficient blood circulation
local bleeding.

The diagnosis of arterial hypertension, as a rule, is not made after a single measurement of pressure, except when it is higher than 170-180 / 105-110 mm Hg. Art.

Measurements are taken over a set period to confirm the diagnosis. It is necessary to take into account the circumstances during which measurements are taken. The pressure gets higher

after smoking or drinking coffee,
against the backdrop of stress.

If the blood pressure in an adult is more than 140/90 mm Hg. Art., then re-measurement, as a rule, is performed after a year. In people whose pressure is from 140/90 to 160/100 mm Hg. st, re-measurement is carried out after a short time. With high diastolic pressure from 110 to 115 mm Hg. Art. urgent treatment is needed.

Elderly people sometimes develop a rare type of hypertension called isolated systolic hypertension. Indicators of systolic pressure, while exceeding 140 mm Hg. Diastolic pressure remains at around 90 mm Hg. st or lower. This type of disease is considered dangerous because it provokes strokes and heart failure.

In addition to measuring blood pressure, the doctor should check for changes in other organs, especially if the pressure is constantly at high values.

The eyes are the only organ of the human body in which blood vessels are clearly visible. With the help of a bright stream of light, the doctor examines the fundus of the eye with a special device - an ophthalmoscope, which allows you to clearly see the narrowing or expansion of blood vessels.

The doctor can see small cracks, hemorrhages, which are the consequences of high blood pressure.

The inspection also includes:

listening with a stethoscope for heart sounds
measuring the size of the heart by palpation,
The use of an electrocardiogram helps to examine the electrical activity of the heart and also to assess its size.

In addition to instrumental studies, the doctor prescribes:

examination of urine to rule out kidney infections,
blood sugar test,
blood test for cholesterol.

The fundus of the eye, kidneys and blood vessels act as target organs for abnormal blood pressure.

Treatment of arterial hypertension

Around the 1950s of the last century, the pharmaceutical industry recorded an increase in the production and synthesis of new groups of antihypertensive drugs.

Previously, the treatment of hypertension involved:

salt free diet
surgical interventions,
phenobarbital as a stress reliever.

There is information that in the early 1940s, every third or fourth place in the hospital was occupied by a patient with hypertension or its consequences. In recent years, a large number of studies have been carried out, which has led to an increase in the effectiveness of the treatment of arterial hypertension. Now the number of deaths and serious consequences of the disease has significantly decreased.

In Russia and Europe, the best medical professionals worked on research and confirmed that only drug treatment of high blood pressure makes it possible to reduce the risk of:

cardiovascular disease,
strokes
lethal outcomes.

However, some people are convinced that arterial hypertension is not treated with medications, as this reduces the quality of life and leads to the development of various side effects, up to depressive states.

Almost all drugs have side effects, but studies show that when using drugs that reduce blood pressure, side effects are recorded in only 5-10% of patients.

The existing variety of groups of drugs that reduce blood pressure allows the doctor and the patient to choose the most optimal treatment. The doctor is obliged to warn the patient about the possible side effects of the drugs used.

Diuretics or pressure diuretics treat blood pressure by increasing the excretion of water and salt by the kidneys. Thus, relaxation of the blood vessels is created.

Diuretics are considered the oldest group of antihypertensive drugs. These drugs have been used since the 50s of the 20th century. They are now also widely used, often in combination with other drugs.

Beta blockers appeared in the 1960s. With the help of drugs, angina pectoris was treated. Beta-blockers reduce blood pressure by acting on the nervous system. They block the influence of beta-nerve receptors on the cardiovascular system.

As a result, the heart rate becomes less active and the volume of blood that is ejected by the heart per minute decreases, which reduces pressure. Beta-blockers also lower the effect of some hormones, so the pressure also normalizes.

Because beta-blockers can constrict peripheral blood vessels, they are not recommended for people with upper or lower extremity circulatory problems.

Calcium channel blockers are a group of drugs that block the flow of calcium within muscle cells. Thus, the frequency of their contractions decreases. All muscle cells need calcium, if it is absent, then the muscles cannot contract normally, the vessels relax and blood flow improves, which lowers blood pressure.

Angiotensin II receptor blockers are the most modern group drugs. Angiotensin II is an effective vasoconstrictor, its synthesis is carried out under the influence of renin, a renal enzyme. Angiotensin II has the main property, it stimulates the production of aldosterone, which delays the excretion of water and salt by the kidneys.

Drugs that block angitensin II receptors. Treatment of hypertension is not complete without these drugs, because they:

prevent further vasoconstriction
facilitate the removal of excess water and salt from the body.

Treatment with ACE inhibitors is widely used for arterial hypertension. With the help of drugs, there is a change in the ratio of compounds in favor of vasodilating biologically active substances. Medicines in this group are usually prescribed to people with hypertension due to kidney disease or heart failure.

Alpha blockers act on the nervous system, but through different receptors than beta blockers. Alpha receptors cause arterioles to contract, so they relax and blood pressure decreases. Alpha-blockers have a side effect - orthostatic hypotension, that is, a sharp decrease in pressure after a person assumes an upright position.

Imidazoline receptor agonists are one of the most promising antihypertensive drugs. Treatment with drugs of this group allows you to eliminate vasospasm, as a result of which the pressure begins to decrease.

Imidazoline receptor agonists are used to treat moderate forms of hypertension and are routinely prescribed in combination therapy.

Non-drug treatment

Therapy of arterial hypertension without medication involves, first of all, reducing salt intake. It is also important to reconsider the amount of alcoholic beverages taken. It is known that drinking more than 80 grams of alcohol per day increases the risk of developing cardiovascular diseases and hypertension.

Overweight is recognized if it exceeds 20% or more of normal body weight, depending on height. Obese people are often prone to developing arterial hypertension. They usually have high cholesterol levels in their blood.

The elimination of excess weight will help not only reduce pressure, but also help prevent dangerous diseases:

atherosclerosis,
diabetes.

It is important to remember that there is no one set diet that will never bring back the weight you have lost.

Arterial hypertension can reduce symptoms if you adhere to such therapy: sports activities,

restriction of salt intake,
diet food intake.

Exercising for half an hour three or four times a week will allow you to achieve weight loss and normalize blood pressure. The educational video in this article will tell you about the dangers of arterial hypertension.

on the

What is hypoxemia and how is it treated?

Hypoxemia is a pathology that can occur at any age. It can affect both adults and unborn children. Lack of oxygen cannot be called a disease, but it is quite possible to give a definition of a pathological condition. Usually, hypoxemia occurs due to diseases associated with cardiovascular, as well as respiratory systems oh. At first glance, a harmless condition is fraught with a threat to the life of the patient, so doctors approach this problem responsibly.

Hypoxemia and its causes

What is hypoxemia? Hypoxemia has a second name - oxygen deficiency. Such a diagnosis is made if the patient has insufficient oxygen in the blood. But for each organ, this component is so important. With its lack, all normal processes are disrupted, the redox balance is gradually disturbed.

It is important to know that an excess of oxygen is also dangerous, so it is necessary to find the very "golden mean" in order to avoid any deviations. In the absence of health problems, the volume of oxygen in the blood should not exceed 65%. This figure is calculated from the total body weight. If we take a standard person, then the weight of oxygen in the blood should be about 40 kg.

Causes of hypoxemia include:

Excess carbon dioxide in the environment. When this component prevails in the air, oxygen is not able to reach the tissues of the human body. The one and only source of oxygen for the blood is air. It is on its qualitative composition that the flow of O2 into the blood depends.

Diseases associated with the lungs. When any pathology occurs in the lung tissue, they are unable to cope with the incoming oxygen. Their work is significantly slowed down, because of this gas is consumed more than it comes in.
Heart defects of various origins, and the circulation of the discharge of blood is disturbed from right to left. If there are violations in the septum of the ventricles of the heart, then there is a mixture of arterial and venous blood, as a result of which the tissues begin to starve. In this case, hypoxemia or hypoxia develops.
Disorders of oxygen metabolism. In this case, a small percentage of O2 is delivered from the patient's blood to the tissues. Such a state may even be quite healthy person. For example, if he overloads his body with physical exercises. Blood circulation is accelerated, and oxygen, in turn, does not have time to properly absorb in the tissues.
Anemia. With this disease, the occurrence of hypoxemia is very common. This is because only hemoglobin is involved in the process of transporting O2 in the body. A decrease in this indicator leads to oxygen starvation of tissues.

Symptoms of hypoxemia

Symptoms of hypoxemia are usually divided into early and late.

Early ones include:

accelerating breathing;
expansion of blood vessels;

increased heart rate;
pressure drop;
rapid fatigue;
indifference to everything around;
frequent headaches turning into dizziness;
very pale skin.

Late symptoms include:

Symptoms may vary. It all depends on the mechanism of hypoxemia. For example, frequent cough, fever, and intoxication of the body appear with pathologies of the lungs. They are what cause oxygen starvation.

If the cause of hypoxemia is anemia, then a few more symptoms are added:

Aversion to food.
Dry skin.
Deterioration of hair and nails.

If arterial hypoxemia manifests itself in children, then the symptoms develop much faster than in adults. This is due to the fact that the child consumes almost twice as much O2. Since the body of babies is growing and all systems are still developing, the suspicion of hypoxemia should be carefully checked.

If the diagnosis is confirmed, then the specialists as soon as possible establish the cause of this condition and begin active treatment. In the absence of the necessary therapy, a small organism will not be able to cope with such a disease on its own. Unpleasant consequences include disturbances in the functioning of the brain, respiratory failure and coma.

During the period of bearing a baby, every expectant mother should be aware of the dangers of hypoxemia. Throughout pregnancy, the fetus is fed with oxygen through the placenta. If there is not enough oxygen in the blood of a pregnant woman, then after a while hypoxemia will develop not only in her, but also in the child.

The causes of hypoxemia in women during the period of bearing a baby include:

neglect of daily walks;
constant stressful situations;
anemia;
pathology of the heart and blood vessels;
kidney disease;
diabetes;

incorrect location of the umbilical cord or placental abruption;
lung pathology;
labor activity that began earlier or later than the due date.

The consequences of intrauterine hypoxemia for a child include:

Slow pulse and breathing.
No crying after birth.
Blue skin tone.
Partial absence of reflexes.
Decreased muscle activity.

Diagnosis of hypoxemia

Methods for diagnosing hypoxemia for newborns, as well as for adult patients include:

hemoximetry, which shows the amount of O2 in arterial blood. The normal rate ranges from 95 to 98%. If they are lowered, then the patient is prescribed the necessary treatment;

a detailed blood test, which determines the number of red blood cells, and also sets the level of hemoglobin;
x-ray of the lungs, with which a specialist can determine the presence of problems with the respiratory system;
an electrocardiogram and an echocardiogram are done to confirm or rule out heart defects.

Methods for determining fetal oxygen deficiency include:

Observation of the movements of the unborn baby. A woman must keep track of her movements herself. When the number of movements is less than 10 times per hour, you should pay attention to this and see a doctor.
A geo-invasive procedure called a non-stress test. This study shows the response of the pulse to fetal movements. In the absence of acceleration, hypoxemia can be judged.
Ultrasound examination of the unborn baby, which is carried out several times during the entire pregnancy. It determines all parameters, including the presence of oxygen deficiency.
Doppler ultrasound is used to determine blood flow pathologies.
Examination of amniotic fluid. This test determines the transparency of amniotic fluid. When their color differs from normal, the doctor can diagnose intrauterine hypoxia.

After identifying a problem with the flow of oxygen into the blood, specialists look for the cause that caused this condition. Treatment must begin immediately, otherwise life-threatening consequences will occur.

Treatment of hypoxemia

When determining a very low oxygen content in the blood, the patient is sent for inpatient treatment. At home, this problem cannot be dealt with. The patient must comply with bed rest, as well as sleep. If complications or respiratory arrest occur, the patient is prescribed artificial ventilation.

If immediately after birth the child does not show signs of life, a special electric pump is used, then the following actions are necessary:

The baby is placed in an incubator in which a humid environment is constantly maintained and oxygen is supplied.
Control of all components of the blood, which is carried out by biochemical analysis.
Particular attention is paid to breathing, as well as the heart and blood vessels.

There are cases when acute arterial hypoxemia develops. These include bronchial asthma, pulmonary edema, accumulation of oxygen in the pleural cavity or when a foreign object enters the respiratory tract. In this situation, the patient needs urgent help.

Everyone should know what it is:

First, it is necessary to rid the upper respiratory tract of all unnecessary.
Second, do artificial respiration and wait for an ambulance.

In the hospital, the patient is connected to a ventilator.

The purpose of drugs also depends on the cause that caused oxygen starvation.

The most popular drugs include:

The list of medications is far from complete. Each of them performs its own action, some complement each other. It is not surprising that in this case it will not do without vitamins. Everyone knows their positive effect on immunity.

For patients with hypoxemia, oxygen therapy is carried out, during which the blood is saturated with O2. This gas is passed through a special tube that is attached to a mask or nasal catheter. The percentage of blood oxygen saturation after this procedure should not exceed 80%. At the same time, antihypoxic drugs are prescribed.

As for alternative medicine, in this case, one should be careful about such therapy. "Grandma's recipes" are not able to cure the problem. These funds will help to get rid of the symptoms for a while, but not from hypoxemia. It is good to combine drug treatment with folk remedies.

Many herbal preparations are able to dilate blood vessels, thin the blood and slow down oxidative processes. Also known plants that have the necessary components for a patient with hypoxemia.

These herbs include:

Infusion of hawthorn helps to actively reduce pressure. To prepare this remedy, you will need about 30 g of hawthorn berries and 1 liter of boiled water. Fruits should be steamed in boiling water for at least 8 hours. The prepared infusion is drunk up to four times a day, 100 ml each.
Nettle tea. You will need a teaspoon of this plant, which must be poured with boiling water. In this state, the broth is kept for an hour, then they drink it instead of regular tea. This drink should not be taken by patients who suffer from kidney disease.
Freshly squeezed juice from black rowan has a beneficial effect on blood vessels. It should be consumed no more than three times a day, one tablespoon.

If the patient decides to try one of the traditional medicine, then you should definitely consult with your doctor. He will evaluate the benefit or futility of this therapy. Independent decisions made about treatment are categorically excluded, since even more harm can be done to health.

The outcome of treatment and the occurrence of complications

What will be the prognosis depends on the type and course of the disease. Arterial hypoxemia in acute form is completely cured very rarely. With fulminant hypoxemia, the patient's body is in a state of shock, in such cases the mortality rate is high. Time runs Not even for minutes, but for seconds. The sooner qualified assistance is provided, the more likely recovery is.

Complications of this disease include:

malfunctions nervous system- the occurrence of convulsions, organic damage to the brain, suppression of breathing, as well as the work of the heart and blood vessels;
a sharp drop in blood pressure, irregular pulse;
pulmonary edema.

Complex arterial hypoxemia in a child in the womb can also provoke death. Death can occur both during gestation and during childbirth. In practice, there are few cases when little patients were saved, whose mothers neglected planned appointments and did not follow all the recommendations of the doctor leading the pregnancy.

Prevention of hypoxemia

Preventive measures include the following:

Every day you need at least half an hour to be in the fresh air. Especially this point should not be neglected by expectant mothers. In this case, walking is important not only for them, but also for the fetus.
Each person should remember about planned receptions. It is on them that the onset of the disease can be detected. The sooner treatment begins, the less likely there will be any complications. Hypoxemia is not to be trifled with.
Gymnastic exercises that contribute to the development of the respiratory system. Many experts recommend adhering to the diaphragmatic breathing technique. This exercise involves vigorous exhalation and inactive inhalation.
Physical activity should be treated with caution. The heart should not be overloaded. Useful activities include swimming in the pool, yoga, and running.
Nutrition must be approached with great responsibility. The diet should contain a lot of vitamins in order to replenish the body with the necessary energy. Healthy foods include fresh fruits and vegetables.

Hypoxemia can be prevented if caught early. This condition can really be avoided if you follow the rules prescribed by doctors.

If you neglect prevention, as well as visiting scheduled appointments with specialists, the consequences can become the most unpleasant. Irreversible processes will begin in all body systems. In this case, it will become much more difficult to deal with the problem.

Violation of the blood circulation of the artery of the retina of the eye

Occlusion of the central retinal artery is an acute blockade, which leads to circulatory disorders, retinal ischemia. It develops in patients older than 60 years. It is noted that men experience this disorder twice as often as women. Most often, occlusion is unilateral. Basically, the development of circulatory disorders occurs precisely in the central artery, and the result is a permanent loss of vision, fortunately, only in one eye.

The reasons
Symptoms
Treatment

The occlusion may involve the central retinal vein. It accompanies the corresponding artery, has the same distribution. In the trunk of the optic nerve, it connects to the central retinal artery. All this leads to a violation of the patency of the vessels of the eye, that is, its occlusion. We can also talk about eye stroke, which occurs just when obstructions form in the arteries and veins, which causes a violation of blood circulation and a decrease or distortion of vision.

How severe the loss of vision will be depends on where the pathology is localized and to what extent it is expressed. An eye stroke develops due to the fact that the blood flow is blocked. Vision problems can occur if structures such as the optic nerve and retina do not receive the nutrients and oxygen they need. When the place of blocking is determined, the type and tactics of its elimination are determined.

It is customary to combine problems with an artery and a vein under a common name - vascular occlusion. Of course, there are differences between the lesions of these vessels. It is important to remember that the obstruction of the central vein does not pose a serious danger to vision, although it certainly requires attention, diagnosis and treatment. But occlusion of the artery leads to unpleasant consequences and visual problems.

The reasons

If we consider the common causes of retinal occlusion, the following should be highlighted:

plaque migration to the arterial site;
giant cell arteritis and other inflammatory diseases;
thrombus in the venous cavity;
other diseases that affect the state of blood vessels, for example, hypertension, diabetes mellitus.

Now we can consider the situation in more detail. The development of an acute disorder of the retinal circulation is associated with thrombosis, spasm, embolism, and collapse of the retinal arterioles. Basically, complete or incomplete occlusion occurs due to the fact that the retinal vessels are clogged with calcified, cholesterol or fibrinous emboli. In any case, occlusion of the central retinal artery is a consequence of systemic chronic or acute pathological processes.

The main risk factors for the development of occlusion largely depend on the person himself. When people lead the wrong way of life, they may assume that they will have problems with the heart, blood vessels, other systems and organs, but they hardly think that because of this their vision may be impaired.

It would seem, how is the way of life connected with the eyes? But every person wants to know the world and receive information with his own eyes, that is, to possess good eyesight. I don't want to lose my sight even for a short period of time, let alone experience it all my life, even with one eye.

In fact, lifestyle also greatly affects the condition of the eye. Risk factors in the elderly and young age are different. In older age, risk factors such as:

persistent high blood pressure;
atherosclerosis;
giant cell arteritis.

At a young age, this may be:

Thrombosis of the central retinal vein

Local provoking factors can also be distinguished, such as retinovasculitis, papilledema, high intraocular pressure, vascular compression of the orbit by retrobulbar hematoma, tumor, ophthalmic surgery, and so on.

As you can see, many of these reasons depend on the person himself. Drinking alcohol frequently and in large quantities, day after day, smoking cigarettes, experiencing frequent stress, a person does not see what processes are taking place in his body. The same applies to a sedentary lifestyle, malnutrition. Meanwhile, first of all, his vessels suffer.

Because of this, blood pressure rises, hypertension develops, and sometimes diabetes mellitus. This applies to all vessels, since blood flows through them throughout the body, delivering nutrients and oxygen to all systems and organs, which are necessary for life. Some people develop heart problems, such as a heart attack, for these and other reasons. A stroke can also occur. And someone is faced with ocular occlusion and it does not bring him anything good.

It is impossible not to take into account the situation when the vessels of the orbit are compressed by the tumor, as well as other reasons that were described earlier. The risk of developing venous occlusion is increased due to retinal periphlebitis, which in turn develops due to Behçet's disease, sarcoidosis.

Systemic diseases, in addition to the already mentioned diabetes mellitus and high blood pressure, include:

hyperlipidemia;
obesity;
thrombophilia;
high blood viscosity and some others.

Again, some of these factors depend on the person himself, other situations are objective. In any case, treatment should be immediate. It is impossible not to mention that fractures of tubular bones, intravenous infections that are associated with the risk of thromboembolism, and a number of other diseases and injuries represent a certain danger in arterial occlusion. Collapse of the retinal arterioles can occur with a large loss of blood, which is due to internal, uterine or gastric bleeding.

With arterial occlusion, blood flow in the affected vessel slows down or stops, which leads to acute retinal ischemia. If blood flow is restored within forty minutes, visual functions may be partially restored. If hypoxia lasts longer than this time, the changes become irreversible, that is, necrosis of ganglion cells, nerve fibers and their subsequent autolysis occur. As a result, occlusion of the central retinal artery leads to atrophy of the optic nerve and permanent loss of vision.

Symptoms

Most often, arterial ocular occlusion develops suddenly and without pain. This means that a person notices an unexpected loss of vision in one eye. Everything happens in just a few seconds. Some people have episodes of short, transient visual impairment. If there is thrombosis of the CAS, visual functions may be impaired after flashes of light. Patients may experience varying degrees of decreased visual acuity. Someone can distinguish objects, but someone does not immediately see anything.

Symptoms of central vein occlusion also do not bring pain, or it occurs very rarely. Unlike arterial occlusion, venous occlusion does not cause vision loss very rapidly. Usually the development of the process occurs within a few hours and even days, in rare cases - weeks.

Treatment

Treatment of arterial ocular occlusion must be started in the first hours! This means that as soon as a person complains of a sharp and painless decrease in vision, you should immediately go to the hospital! You can not pull, otherwise you will have to part with part of the vision. Is there any way to provide first aid? Yes! It consists in the implementation of a massage of the eyeball, which will restore blood flow in the CAS. To lower IOP, doctors instill eye drops, diuretics, and paracentesis of the cornea.

If the disorder is caused by spasm of arterioles, the ophthalmologist treats with the use of vasodilators, performs inhalations of carbogen. If there is thrombosis of the CAS, it is necessary to use thrombolytics and anticoagulants, probing of the branches of the artery is also prescribed.

If there is an occlusion of the central retinal vein, the treatment is carried out in an ophthalmology hospital, and then on an outpatient basis. The goal of intensive therapy is to restore venous blood flow, resolve hemorrhage, reduce edema, and improve retinal trophism. Antiplatelet agents, diuretics, vasodilators are prescribed. Sometimes thrombolytics and drugs that dilate blood vessels are administered with the help of a catheter.

Prevention of occlusion is associated with timely treatment of the existing pathology. It is necessary to exclude provoking factors, such as smoking, alcohol, stress. It is better not to visit baths, saunas, or take hot baths. You should also abandon long flights by plane, scuba diving. Of course, such measures are not necessary for everyone. They are useful for those who have already had occlusion, but managed to avoid loss of vision. The indicated prevention should be followed if there are risk factors and the likelihood of developing occlusion.

This vision disorder is not fatal, but very unpleasant. Most of the time it can be avoided. If this did not work out, you need to immediately deal with occlusion, using modern methods of treatment.

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Even people who are far from mountaineering and diving know that it becomes difficult for a person to breathe in certain conditions. This phenomenon is associated with a change in the partial pressure of oxygen in the environment, as a result, in the blood of the person himself.

mountain sickness

When a resident of the flat area comes on vacation to the mountains, it seems that the air there is especially clean and it is simply impossible to breathe it.

In fact, such reflex urges for frequent and deep breathing are caused by hypoxia. In order for a person to equalize the partial pressure of oxygen in the alveolar air, he needs to ventilate his own lungs as best as possible at first. Of course, staying in the mountains for several days or weeks, the body begins to get used to the new conditions by adjusting the work internal organs. So the situation is saved by the kidneys, which begin to secrete bicarbonate to enhance ventilation of the lungs and increase the number of red blood cells in the blood that can carry more oxygen.

Thus, in mountainous areas, the level of hemoglobin is always higher than in the plains.

acute form

Depending on the characteristics of the organism, the norm of partial pressure of oxygen may differ for each person at a certain age, state of health, or simply from the ability to acclimatize. That is why not everyone is destined to conquer the peaks, because even with a great desire, a person is not able to completely subjugate his body and make it work differently.

Very often, unprepared climbers with high-speed ascent may develop various symptoms of hypoxia. At an altitude of less than 4.5 km, they are manifested by headaches, nausea, fatigue and a sharp change in mood, since the lack of oxygen in the blood strongly affects the functioning of the nervous system. If such symptoms are ignored, then swelling of the brain or lungs is formed, each of which can lead to death.

Thus, it is strictly forbidden to ignore the change in the partial pressure of oxygen in the environment, because it always affects the performance of the entire human body.

Immersion under water

When a diver dives into conditions where the atmospheric pressure is below the usual level, his body also faces a kind of acclimatization. The partial pressure of oxygen at sea level is an average value and also changes with immersion, but nitrogen is a particular danger to humans in this case. On the surface of the earth in flat terrain, it does not affect people, but after every 10 meters of immersion, it gradually contracts and provokes various degrees of anesthesia in the diver's body. The first signs of such a violation may appear after 37 meters under water, especially if a person spends a long time at depth.

When atmospheric pressure exceeds 8 atmospheres, and this figure is reached after 70 meters under water, divers begin to feel nitrogen narcosis. This phenomenon is manifested by the feeling alcohol intoxication, which violates the coordination and attentiveness of the submariner.

To avoid the consequences

In the case when the partial pressure of oxygen and other gases in the blood is abnormal and the diver begins to feel signs of intoxication, it is very important to lift it as slowly as possible. This is due to the fact that with a sharp change in pressure, nitrogen diffusion provokes the appearance of bubbles with this substance in the blood. In simple terms, the blood seems to boil, and the person begins to feel severe pain in the joints. In the future, he may develop impaired vision, hearing and the functioning of the nervous system, which is called decompression sickness. To avoid this phenomenon, the diver should be lifted very slowly or replaced with helium in his breathing mixture. This gas is less soluble, has a lower mass and density, so the costs are reduced.

If such a situation has occurred, then the person must be urgently placed back in the environment with high pressure and wait for gradual decompression, which can last up to several days.

In order to change the gas composition of the blood, it is not necessary to conquer peaks or descend to the seabed. Various pathologies of the cardiovascular, urinary and respiratory systems can also affect the change in gas pressure in the main fluid of the human body.

To accurately determine the diagnosis, appropriate tests are taken from patients. Most often, doctors are interested in the partial pressure of oxygen and carbon dioxide, since they provide full breathing of all human organs.

Pressure in this case is a process of dissolving gases, which shows how efficiently oxygen works in the body and whether its performance is in line with the norms.

The slightest deviations indicate that the patient has deviations that affect the ability to use the gases entering the body to the maximum.

Pressure standards

The norm of the partial pressure of oxygen in the blood is a relative concept, since it can vary depending on many factors. In order to correctly determine your diagnosis and receive treatment, it is necessary to contact a specialist with the results of the tests, who can take into account all the individual characteristics of the patient. Of course, there are reference norms that are considered ideal for a healthy adult. So, in the patient's blood without deviations there is:

carbon dioxide in the amount of 44.5-52.5%;
its pressure is 35-45 mm Hg. Art.;
saturation of the liquid with oxygen 95-100%;
About 2 in the amount of 10.5-14.5%;
partial pressure of oxygen in the blood 80-110 mm Hg. Art.

In order for the results to be true during the analysis, it is necessary to take into account a number of factors that can affect their correctness.

Causes of deviation from the norm, depending on the patient

The partial pressure of oxygen in arterial blood can change very quickly depending on various circumstances, therefore, in order for the analysis result to be as accurate as possible, the following features should be considered:

the rate of pressure always decreases with increasing age of the patient;
when supercooling, the pressure of oxygen and the pressure of carbon dioxide decrease, and the pH level increases;
when overheating, the situation is reversed;
the actual indicator of the partial pressure of gases will be visible only when blood is taken from a patient with a body temperature within the normal range (36.6-37 degrees).

Causes of deviation from the norm, depending on health workers

In addition to taking into account such features of the patient's body, specialists must also comply with certain norms for the correctness of the results. First of all, the presence of air bubbles in the syringe affects the partial pressure of oxygen. In general, any contact of the assay with ambient air can change the results. It is also important to gently mix the blood in the container after taking the blood so that the erythrocytes do not settle at the bottom of the tube, which can also affect the results of the analysis, demonstrating the level of hemoglobin.

It is very important to adhere to the norms of the time allotted for the analysis. According to the rules, all actions must be carried out within a quarter of an hour after sampling, and if this time is not enough, then the blood container should be placed in ice water. This is the only way to stop the process of oxygen consumption by blood cells.

Specialists should also calibrate the analyzer in a timely manner and take samples only with dry heparin syringes, which are electrolytically balanced and do not affect the acidity of the sample.

Test results

As is already clear, the partial pressure of oxygen in the air can have a noticeable effect on the human body, but the level of gas pressure in the blood can be disturbed for other reasons. To determine them correctly, decoding should be trusted only by an experienced specialist who is able to take into account all the features of each patient.

In any case, hypoxia will be indicated by a decrease in the level of oxygen pressure. A change in blood pH, as well as carbon dioxide pressure or a change in bicarbonate levels, may indicate acidosis or alkalosis.

Acidosis is a process of acidification of the blood and is characterized by an increase in carbon dioxide pressure, a decrease in blood pH and bicarbonates. In the latter case, the diagnosis will be announced as metabolic acidosis.

Alkalosis is an increase in the alkalinity of the blood. It will be indicated by an increased pressure of carbon dioxide, an increase in the number of bicarbonates, and, consequently, a change in the pH level of the blood.

Conclusion

The performance of the body is affected not only by high-quality nutrition and physical activity. Each person gets used to certain climatic conditions of life in which he feels as comfortable as possible. Their change provokes not only poor health, but also a complete change in certain blood parameters. To determine the diagnosis from them, you should carefully select a specialist and monitor compliance with all norms for taking tests.

PaO2, along with two other quantities (paCO2 and pH), make up such a concept as "blood gases" (Arterial blood gases - ABG (s)). The value of paO2 depends on many parameters, the main of which are the age and height of the patient (partial pressure of O2 in atmospheric air). Thus, pO2 must be interpreted individually for each patient.
Accurate results for ABGs depend on the collection, processing, and actual analysis of the sample. Clinically important errors can occur at any of these steps, but blood gas measurements are particularly vulnerable to errors that occur prior to analysis. The most common problems include
- sampling of non-arterial (mixed or venous) blood;
- the presence of air bubbles in the sample;
- insufficient or excessive amount of anticoagulant in the sample;
- delaying the analysis and keeping the sample uncooled all this time.

A proper blood sample for ABG analysis typically contains 1-3 ml of arterial blood drawn anaerobically from a peripheral artery into a special plastic container using a small diameter needle. Air bubbles that may enter during sampling must be removed immediately. The air in the room has a paO2 of about 150 mmHg. (at sea level) and paCO2 is practically equal to zero. Thus, air bubbles that mix with arterial blood shift (increase) paO2 to 150 mm Hg. and reduce (decrease) paCO2.

If heparin is used as an anticoagulant and the sampling is done with a syringe and not with a special container, the pH of heparin, which is approximately 7.0, should be taken into account. Thus, an excess of heparin can change all three ABG values (paO2, paCO2, pH). A very small amount of heparin is needed to prevent clotting; 0.05 - 0.10 ml of a dilute solution of heparin (1000 IU / ml) will counteract the clotting of approximately 1 ml of blood without affecting pH, paO2, paCO2. After flushing the syringe with heparin, a sufficient amount of heparin usually remains in the dead space of the syringe and needle, which is enough to anticoagulate without distorting the ABG values.

After collection, the sample should be analyzed as soon as possible. If a delay of more than 10 minutes occurs, the sample must be immersed in a container with ice. Leukocytes and platelets continue to consume oxygen in the sample after collection, and can cause a significant drop in paO2 when stored for long periods at room temperature, especially under conditions of leukocytosis or thrombocytosis. Cooling will prevent any clinically important changes for at least 1 hour by reducing the metabolic activity of these cells.

1.8 Partial tension of oxygen in the blood

PaO2 is the partial tension of oxygen in arterial blood. This is the tension of physically distributed oxygen in arterial blood plasma under the influence of a partial pressure equal to 100 mm Hg (PaO2 = 100 mm Hg). Every 100 ml of plasma contains 0.3 ml of oxygen. The content of O2 in arterial blood in trained athletes at rest does not differ from its content in non-athletes. During physical activity in the arterial blood flowing to the muscles, an accelerated breakdown of oxyhemoglobin occurs with the release of free O2, so PaO2 increases

PvO2 - partial tension of oxygen in venous blood. This is the tension of physically dissolved oxygen in the venous blood plasma flowing from the tissue (muscle). It characterizes the ability of tissue to utilize oxygen. At rest it is equal to 40-50 mm Hg. At maximum work, due to the intensive utilization of O2 by working muscles, it decreases to 10-20 mm Hg. Art.

The difference between PaO2 and PvO2 is the value of AVR-O2 - the arterial-venous oxygen difference. It characterizes the ability of tissue to utilize oxygen. ABP-O2 - the difference between the oxygen content in arterial blood ejected into the systemic arteries from the left ventricle and in venous blood flowing to the right atrium.

With the development of aerobic endurance, a pronounced sarcoplasmic hypertrophy of skeletal muscles occurs, which leads to a decrease in oxygen in the venous blood (PvO2), and a corresponding increase in ABP-O2. So if at rest PvO2 in men and women is 30 mm Hg, then after endurance exercise in untrained men PvO2 = 13 mm Hg, in untrained women 14 mm Hg. Accordingly, in trained men and women, 10 and 11 mm Hg. In women, the content of hemoglobin, bcc and oxygen content in arterial blood is less, therefore, with an equal oxygen content in venous blood, the total systemic ABP-O2 in women is less. At rest, it is equal to 5.8 ml of O2 per 100 ml of blood, against 6.5 in men. After the exercise, in untrained women, ABP-O2 = 11.1 ml O2 / 100 ml of blood, versus 14 in untrained men. As a result of training, ABP-O2 increases in both women and men as a result of a decrease in the oxygen content in venous blood (12.8 and 15.5, respectively).

According to Fick's formula (PO2(MPC)=CB*AVR-O2), the product of CB by AVR-O2 determines the maximum oxygen consumption and is an important indicator of aerobic endurance. Endurance athletes use their oxygen transport capabilities more efficiently, as they use more oxygen contained in each milliliter of blood than untrained people.

1.9 The influence of health training on the body's hemodynamics

As a result of health training, the functional capabilities of the cardiovascular system increase. There is an economization of the work of the heart at rest and an increase in the reserve capacity of the circulatory apparatus during muscle activity. One of the most important effects of physical training is a decrease in heart rate at rest (bradycardia) as a manifestation of the economization of cardiac activity and a lower myocardial oxygen demand. Increasing the duration of the diastole (relaxation) phase provides more blood flow and a better supply of oxygen to the heart muscle. In individuals with bradycardia, cases of coronary heart disease (CHD) were detected much less frequently than in people with a fast pulse. It is believed that an increase in heart rate at rest by 15 beats / min increases the risk of sudden death from a heart attack by 70%. The same pattern is observed with muscle activity.

When performing a standard load on a bicycle ergometer in trained men, the volume of coronary blood flow is almost 2 times less than in untrained men (140 vs. /min per 100g of fabric). Thus, with an increase in the level of fitness, myocardial oxygen demand decreases both at rest and at submaximal loads, which indicates the economization of cardiac activity. As fitness increases and myocardial oxygen demand decreases, the level of threshold load increases, which the subject can perform without the threat of myocardial ischemia and an angina attack.

The most pronounced increase in the reserve capacity of the circulatory apparatus during intense muscular activity: an increase in maximum heart rate, CO and CO, AVR-O2, a decrease in total peripheral vascular resistance, which facilitates the mechanical work of the heart and increases its productivity. Adaptation of the peripheral link of blood circulation is reduced to an increase in muscle blood flow at maximum loads (maximum 100 times), an arteriovenous difference in oxygen, the density of the capillary bed in working muscles, an increase in the concentration of myoglobin and an increase in the activity of oxidative enzymes.

A protective role in the prevention of cardiovascular diseases is also played by an increase in blood fibrinolytic activity during health-improving training (by a maximum of 6 times) and a decrease in the tone of the sympathetic nervous system. As a result, the response to neurohormones decreases under conditions of emotional stress, i.e. increases the body's resistance to stress.

In addition to a pronounced increase in the body's reserve capacity under the influence of health training, its preventive effect is also extremely important. With the growth of fitness (as the level of physical performance increases), there is a clear decrease in all major risk factors: blood cholesterol, blood pressure and body weight. There are examples when, as UFS increased, the cholesterol content in the blood decreased from 280 to 210 mg, and triglycerides from 168 to 150 mg%. At any age, with the help of training, you can increase aerobic capacity and endurance levels - indicators of the biological age of the body and its viability. For example, in well-trained middle-aged runners, the maximum possible heart rate is about 10 bpm more than in untrained ones. Physical exercises such as walking, running (3 hours per week), after 10-12 weeks, lead to an increase in BMD by 10-15%.

Thus, the healing effect of mass physical education is primarily associated with an increase in the aerobic capacity of the body, the level of general endurance and physical performance. An increase in working capacity is accompanied by a preventive effect on risk factors for cardiovascular diseases: a decrease in body weight and fat mass, cholesterol and triglyceride levels in the blood, a decrease in blood pressure and heart rate. In addition, regular physical training can significantly slow down the development of age-related changes in physiological functions, as well as degenerative changes in various organs and systems (including the delay and reverse development of atherosclerosis). Performing physical exercises has a positive effect on all parts of the motor apparatus, preventing the development of degenerative changes associated with age and physical inactivity. The mineralization of bone tissue and the calcium content in the body increase, which prevents the development of osteoporosis. Increased lymph flow to the articular cartilage and intervertebral discs, which is the best remedy prevention of arthrosis and osteochondrosis. All these data testify to the invaluable positive impact of health-improving physical culture on the human body.

Conclusion

In this course work, the main hemodynamic characteristics and their changes during physical activity were considered. Brief conclusions are summarized in Table 10.

Table10. Basic hemodynamic characteristics

	Definition	Characteristic.	training effect
heart rate	HR-frequency of the heart. beats per minute (heart rate).	resting heart rate avg. For men - 60 beats / min for women - 75, for trained. husband. -55, for outstanding athletes - 50 beats / min. Min. the recorded heart rate of rest in athletes is 21 beats/min. HR max avg. men 200 beats / min, for trained - 195, for supersportsmen -190 beats / min (exercise max. aerobic power), 180 beats / m (max. anaerobic power), heart rate max for untrained women - 205 beats / min, for athletes - 195 beats / min.	A decrease in heart rate (bradycardia) is an effect of endurance training and leads to a decrease in myocardial oxygen demand.
SO	CO=SV/HR The amount of blood ejected by each of the ventricles of the heart during one contraction.	Sopokoya in untrained men on average 70-80 ml, in trained men - 90 ml, in outstanding athletes - 100-120 ml. With a maximum aerobic load, COmax for untrained young men is 120-130 ml, trained - 150, for outstanding athletes - 190-210 ml. COmax for untrained women 90 ml, for outstanding athletes 140-150 ml.	An increase in CO as a result of training is a sign of an increase in the efficiency of the heart.
CB or IOC or Q	SV=SD*HR SV=PO2/AVR-O2 Amount of blood ejected by the heart in 1 min IOC - Volume of blood passing through. through the bloodstream. vessels in units of time Q=P/R- Blood flow	CV at rest in men = 4-5 l / min, in women - 3-5 l / min. CV max average in untrained men - 24 l / min, in super athletes (training endurance) and those with large volume heart (1200-1300 ml) - more than 30 l / min - for skiers CBmax \u003d 38–42 l / min. In untrained women, CB-18l / min. Outstanding sportswomen have CVmax=28-30. The basic equation of hemodynamics P-blood pressure, R-vascular resistance.	One of the main effects of endurance training is an increase in CBmax. The increase in CO is not due to heart rate, but due to CO
HELL	SBP - Systolic blood pressure - max. blood pressure on the aortic wall, achieved at the time of CO DBP-DiastolicBP blood pressure with which it returns to the atrium in diastole.	Standards AD-100-129 mm Hg. for max. and 60-79 mm Hg. for the minimum for persons under 39 years old The upper limit of normal systolic pressure from 21 to 60 years old is 140 mm Hg, for diastolic pressure - 90 mm Hg. With a slight physical load, ADmax rises to 130-140 mm Hg, with an average one up to 140-170, with a big one up to 180-200. ADmin, usually with physical. load is reduced. With hypertension and physical exertion, SBPmax = 250 mm Hg. An increase in blood pressure is associated with an increase in R and CO.	Sports activities help lower blood pressure, but blood pressure does not go beyond the normal range. Dynamic loads (exercise for endurance) contribute to a decrease in blood pressure, static loads (exercises for strength) - to increase blood pressure.
R	3.14*R^4-Vascular or peripheral. resisted	Depends on the L-length of the vessel, n-blood viscosity, R-radius of the vessel; 3.14 is the number of Pi.	Redistribution of blood flow, increased capillarization, slowing down of blood flow in highly trained athletes.
BCC	BCC - Circulating blood volume - the total amount of blood in the blood vessels.	It makes up 5-8% of the weight, at rest in women - 4.3 liters, in men - 5.5 liters. Under load, the BCC first increases and then decreases by 0.2-0.3 liters due to the outflow of part of the plasma from the capillaries into the intercellular space. In women with max. work BCC average = 4l, in men - 5.2l. With a load of max. aerobic power in trained men, BCC average \u003d 6.42 l.	Increase in BCC during endurance training.
PaO2, PvO2	PaO2, PvO2 - Partial tension of oxygen in arterial or venous blood. partial pressure. PaO2-PvO2 = AVR-O2 arterial-venous oxygen difference	PaO2-100mmHg PvO2pok-40-50mmHg PvO2max work=10-20mmHg If PvO2 of rest in men and women is 30 mm Hg, then after endurance exercise in untrained men PvO2 = 13 mm Hg, women 14 mm Hg. Accordingly, in trained men and women, 10 and 11 mm Hg. ABP-O2 at rest = 5.8 mlO2 / 100 ml of blood, against 6.5 in men. After exercise, in untrained women, ABP-O2 = 11.1 mlO2 / 100 ml of blood, versus 14 in men. As a result of training ABP-O2 in women - 12.8, in men - 15.51 mlO2 / 100 ml of blood.	Sarcoplasmic hypertrophy of skeletal muscles leads to a decrease in the oxygen content in the venous blood PvO2 and an increase in ABP-O2. Consequently, the BMD increases.

In column 3 is given a brief description of studied quantities and their limiting values.

The degree of change in hemodynamic parameters during exercise depends on the initial values at rest. Physical activity requires a significant increase in the functions of the cardiovascular, respiratory and circulatory systems. The provision of working muscles with a sufficient amount of oxygen and the removal of carbon dioxide from the tissues depends on this. The cardiovascular system has a number of mechanisms that allow delivering as much blood as possible to the periphery. First of all, these are hemodynamic factors: an increase in heart rate, CO, BCC, acceleration of blood flow, changes in blood pressure. These indicators are different for representatives of various sports. (According to sports specialization, sprinters train speed, stayers train endurance, weightlifters train strength.)

The use of the echocardiography method in sports medicine made it possible to establish the difference in the ways of heart adaptation, depending on the direction of the training process. In athletes training endurance, adaptation of the heart occurs mainly due to dilation with slight hypertrophy, and in athletes training strength - due to true myocardial hypertrophy and slight dilation. With increased physical work, cardiac activity increases. The heart should be trained gradually according to age.

Such a hemodynamic factor as a change in blood pressure is very important. The direction of the training process affects blood pressure. Physical loads of a dynamic nature contribute to its reduction, static loads - to its rise. Hypertension can be caused by physical and emotional stress. A low level of systolic pressure in the pulmonary artery is an indicator high state cardiovascular system of endurance athletes. It characterizes the potential readiness of the body, in particular hemodynamics, for large and prolonged physical exertion.

The physiological changes in the body caused by endurance training are the same in women as in men. So, in the oxygen transport system, the maximum indicators increase (LVmax, CBmax, COmax), lactate concentration at maximum work, and HRmax decreases due to increased parasympathetic influences. All this indicates an increase in efficiency and economy, as well as an increase in the reserve capacity of the oxygen transport system.

The state of the body both at rest and under load depends on many factors: on external conditions, the specifics of sports (swimming, winter sports, etc.), hereditary factors, gender, age, etc.

The limit of growth of training effects in each person is genetically predetermined. Even systematic intense physical training cannot increase the functional capabilities of the body beyond the limit determined by the genotype. Resting heart rate, heart size, left ventricular wall thickness, myocardial capillarization, coronary artery wall thickness are influenced by hereditary factors.

It must be borne in mind that physical exercises promote health, improve the biological mechanisms of protective and adaptive reactions, increase nonspecific resistance to various harmful environmental influences, only under the obligatory condition that the degree of physical activity in these classes is optimal for this particular person. Only the optimal degree of physical activity, corresponding to the capabilities of the person performing it, provides health promotion, physical improvement, prevents the occurrence of a number of diseases and increases life expectancy. Physical activity less than optimal does not give the desired effect, more than optimal becomes excessive, and excessive exercise, instead of a healing effect, can cause various diseases and even sudden death from heart overstrain. Sports achievements should grow due to improved health.

Special mention should be made of the influence of health physical education on the aging body. Physical culture is the main means of delaying age-related deterioration in physical qualities and a decrease in the adaptive abilities of the body as a whole and the cardiovascular system in particular. Changes in the circulatory system, a decrease in the performance of the heart entail a pronounced decrease in the maximum aerobic capacity of the body, a decrease in the level of physical performance and endurance. The rate of age-related decrease in BMD in the period from 20 to 65 years in untrained men is on average 0.5 ml / min / kg, in women - 0.3 ml / min / kg per year. In the period from 20 to 70 years, the maximum aerobic productivity decreases by almost 2 times - from 45 to 25 ml / kg (or by 10% per decade). Adequate physical training, health-improving physical culture can largely stop age-related changes in various functions. Particularly useful are physical labor, physical education and sports in the fresh air, and smoking and alcohol abuse are especially harmful to the cardiovascular system.

The above material traced the patterns of changes in the main hemodynamic characteristics of the body. A simultaneous increase in the level of health and functional state of a person is impossible without the active, wide and comprehensive use of physical culture and sports.

Literature

1.A.S. Zalmanov. The secret wisdom of the human body (Deep Medicine) .- M .: Nauka, 1966.- 165p.

2.sports medicine(Guide for doctors) / edited by A.V. Chogovadze, L.A. Butchenko.-M.: Medicine, 1984.-384p.

3.Sports physiology: Textbook for institutes of physical culture / Ed. Ya.M.Kotsa.-M.: Physical culture and sport, 1986.-240s.

4. Dembo A.G. Medical control in sports.-M.: Medicine.1988.-288p.

5.A.M.Tsuzmer, O.L.Petrishina. Human. Anatomy. Physiology. Hygiene.-M.: Education, 1971.-255s.

6.V.I. Dubrovsky, Rehabilitation in sports. - M .: Physical culture and sport, 1991. - 208 p.

7. Melnichenko E.V. Guidelines to the theoretical study of the course "Sports Physiology". Simferopol. 2003.

8. Grabovskaya E.Yu. Malygina V.I. Melnichenko E.V. Guidelines for the theoretical study of the course "Physiology of muscle activity." Simferopol. 2003

9. Dembo A.G. Actual problems of modern sports medicine.-M.: Physical culture and sport, 1980.-295s.

10. Byleeva L.V. etc. Mobile games. Textbook for in-t of physical culture. M.: Physical culture and sport, 1974.-208s.

A.S. Zalmanov. Secret wisdom of the human body (Deep Medicine).- Moscow: Nauka, 1966.- C32.

Sports medicine (Guide for doctors) / edited by A.V. Chogovadze, L.A. Butchenko.-M.: Medicine, 1984.-C83.

Sports medicine (Guide for doctors) / edited by A.V. Chogovadze, L.A. Butchenko.-M.: Medicine, 1984.-C76.

Sports Physiology: Textbook for in-t fiz.kut./Ed. Ya.M.Kotsa.-M.: Physical culture and sport, 1986.-S.87.

Sports Physiology: Textbook for in-t fiz.kut./Ed. Ya.M.Kotsa.-M.: Physical culture and sport, 1986.-S.29

Dembo A.G. Medical control in sports.-M.: Medicine.1988.-C137.

Sports Physiology: Textbook for in-t fiz.kut./Ed. Ya.M.Kotsa.-M.: Physical culture and sport, 1986.-S.202

Sports medicine (Guide for doctors) / edited by A.V. Chogovadze, L.A. Butchenko.-M.: Medicine, 1984.-C97.

...) and relative (with significant dilatation of the left ventricle with aortic opening) insufficiency of the aortic valve. Etiology 1) RL; 2) FROM; 3) syphilitic aortitis; 4) diffuse diseases of the connective tissue; 5) aortic atherosclerosis; 6) injury; 7) congenital defect. Pathogenesis and changes in hemodynamics. The main pathological process leads to wrinkling (rheumatism, ...

Literature data on the issue under study; 2) evaluate the morphological and functional indicators of participants in groups of various trained orientations on initial stage; 3) to determine the effect of aerobic and anaerobic physical exercises on the morphological and functional capabilities of those involved; 4) to carry out a comparative analysis of the indicators of the studied group members in the dynamics of the training process. 2.2...

An electrocardiographic technique is mainly used to detect physiological and pathological changes in the heart, while we did not find any works where ECG indicators were used to determine fitness and the effect of physical activity on changes in heart rate and blood pressure. that at rest the studied values in gymnasts 15-16 years old ...

With a decrease in barometric pressure, the partial pressure of the main gases that make up the atmosphere also decreases. The quantitative composition of the air mixture in the troposphere remains virtually unchanged. So atmospheric air under normal conditions (at sea level) contains 21% oxygen, 78% nitrogen, 0.03% carbon dioxide, and almost % is inert gases: helium, xenon, argon, etc.

Partial pressure(lat. partialis - partial, from lat. pars - part) - the pressure of a single component of the gas mixture. The total pressure of a gas mixture is the sum of the partial pressures of its components.

The partial pressure of a gas in atmospheric air is determined by the formula:

Ph is the barometric pressure at the actual altitude.

A decisive role in maintaining human life is played by gas exchange between the body and the external environment. Gas exchange is carried out due to respiration and blood circulation: oxygen continuously enters the body, and carbon dioxide and other metabolic products are released from the body. In order for this process not to be disturbed, it is necessary to support partial pressure of oxygen in the inhaled air at a level close to the earth.

Partial pressure of oxygen (O 2) in air is called the part of the total air pressure attributable to O 2.

So, at sea level (Н=0m), in accordance with (1.1), the partial pressure of oxygen will be:

where αO 2 \u003d 21% is the gas content in atmospheric air in%;

P h \u003d 0 - barometric pressure at sea level

With increasing altitude, the total pressure of gases decreases, however, the partial pressure of such constituent parts, as carbon dioxide and water vapor in the alveolar air, remains virtually unchanged.

And equal, at a human body temperature of 37 0 C approximately:

· for water vapor РН 2 О=47mm Hg;

· for carbon dioxide РСО 2 =40 mm Hg.

This significantly changes the rate of oxygen pressure drop in the alveolar air.

Atmospheric pressure and air temperature at heights

according to international standard

Table 1.4

No. p / p	Height, m	Barometric pressure, mm Hg	Air temperature, 0 C
1.
2.		715,98	11,75
3.		674,01	8,5
4.		634,13	5,25
5.		596,17
6.		560,07	-1,25
7.		525,8	-4,5
8.		493,12	-7,15
9.		462,21	-11,0
10.		432,86	-14,25
11.		405,04	-17,5
12.		378,68	-20,5
13.		353,73	-24,0
14.		330,12	-27,25
15.		307,81	-30,5
16.		286,74	-33,75
17.		266,08	-37,0
18.		248,09	-40,25
19.		230,42	-43,5
20.		213,76	-46,75
21.		198,14	-50,0
22.		183,38	-50,25
23.		169,58	-56,5
24.		156,71	-56,5
25.		144,82	-56,5
26.		133,83	-56,5
27.		123,68	-56,5
28.		114,30	-56,5
29.		105,63	-56,5
30.		97,61	-56,5
31.		90,21	-56,5
32.		83,86	-56,5

Alveolar air- a mixture of gases (mainly oxygen, carbon dioxide, nitrogen and water vapor) contained in the pulmonary alveoli, directly involved in gas exchange with blood. The supply of oxygen to the blood flowing through the pulmonary capillaries and the removal of carbon dioxide from it, as well as the regulation of respiration, depend on the composition maintained in healthy animals and humans within certain narrow limits due to ventilation of the lungs (in humans, it normally contains 14-15% oxygen and 5-5.5% carbon dioxide). With a lack of oxygen in the inhaled air and some disease states, changes in the composition occur, which can lead to hypoxia.