Human heart chambers: description, structure, functions and types

The heart is the most important organ in the human body. His study deals with scientists of all fields of knowledge. People are trying to find a way to prolong the health of the heart muscle, improve its performance. Knowledge of the anatomy, physiology and pathology of the heart, even to the average person, will help to better understand the processes that occur in our body. How many cameras are in the heart of a person? Where do the circles of circulation begin and end? How does the blood supply the heart? All of these questions will be answered in this article.

Anatomy of the heart

The heart is a three-layered sac. Outside it covers the pericardium (protective bag), followed by the myocardium (contracting muscle) and endocardium (a thin mucous plate covering the inside of the heart chamber).

In the human body, the organ is located in the center of the thorax. It is somewhat deviated from the vertical axis, so most of it is on the left. The heart consists of chambers - four cavities, which communicate with each other by means of valves. These are the two atriums (right and left) and two ventricles that are underneath them. Between them, they are separated by valves, which prevent the reverse flow of blood.

The walls of the ventricles are thicker than the walls of the atria, and they are larger in volume, since their work consists in pushing blood into the vasculature, while the atria passively take up the liquid.

Features of heart structure in fetus and newborn

How many cameras are in the heart of a person who has not yet been born? They are also four, but the atria are communicating with each other through an oval hole in the septum. At the stage of embryogenesis, it is necessary for the discharge of blood from the right parts of the heart to the left, since there is still a small circle of circulation - the lungs are not straightened. But the blood in the developing respiratory organs still arrives, and it goes directly from the aorta through the botalla duct.

The fetal heart chambers are thinner and much smaller than in the adult, and only thirty percent of the total mass of the myocardium is reduced. Its functions are closely related to the intake of glucose into the mother's bloodstream, since the child's heart muscle uses it as a nutrient substrate.

Blood supply and circulation

The blood supply of the myocardium occurs at the time of systole, when blood under pressure enters the main vessels. Vessels of the chambers of the heart are located in the thickness of the myocardium. Large coronary arteries depart directly from the aorta and when the ventricles contract, part of the blood goes to feed the heart. If this mechanism is broken at any stage, myocardial infarction occurs.

Human heart cells perform a pumping function. From the point of view of physics, they simply pump liquid in a closed circle. The pressure that is created in the cavity of the left ventricle, during its contraction, will bring blood acceleration in order for it to reach even the smallest capillaries.

There are two circles of blood circulation:

- large, designed to nourish body tissues;

- small, functioning exclusively in the lungs and supporting gas exchange.

Bearing and bearing vessels has every chamber of the heart. Where does blood flow through the great circle of blood circulation? From the left atrium fluid enters the left ventricle and fills it, thereby increasing the pressure in the cavity. When it reaches 120 mm of water column, a semilunar valve separating the ventricle from the aorta opens and blood enters the systemic circulation. After all capillaries have been filled, the process of cellular respiration and nutrition takes place. Then, through the venous system, the blood flows back to the heart, or more precisely, to the right atrium. The upper and lower hollow veins that collect blood from the entire body approach it. When the fluid accumulates a sufficient amount, it rushes into the right ventricle.

From it begins a small circle of blood circulation. Saturated with carbon dioxide and metabolic products, the blood enters the pulmonary trunk. And thence to the arteries and capillaries of the lungs. Through the hematoalveolar barrier, gas exchange occurs with the external environment. Already rich in oxygen, the blood returns to the left atrium to re-enter the large circle of circulation. The whole cycle takes less than thirty seconds.

Cycle of work

In order for the body to constantly receive the necessary nutrients and oxygen, the chambers of the heart should work very well. There is a nature of the order of action.

1. Systole is the contraction of the ventricles. It is divided into several periods:

• Stress: individual myofibrils contract, the pressure in the cavity rises, the valve between the atria and the ventricles closes. Because of the simultaneous reduction of all muscle fibers, the configuration of the cavity changes, the pressure rises to 120 mm of water column.
• Exile: open the semilunar valves - the blood enters the aorta and pulmonary trunk. The pressure in the ventricles and atria is gradually leveled, and the blood completely leaves the lower chambers of the heart.

2. Diastole is a relaxation of the myocardium and a period of passive blood intake. The upper chambers of the heart communicate with the receiving vessels and accumulate a certain amount of blood. Then the atrioventricular valves open and the fluid enters the ventricles.

Diagnosis of disorders in the structure and work of the heart

1. Electrocardiography. This is the registration of electronic phenomena that accompany muscle contractions. Chambers of the heart consist of cardiomyocytes, which before each contraction generate an action potential. It is this that is fixed by the electrons superimposed on the chest. Due to this method of visualization, it is possible to detect gross violations in the work of the heart, its organic or functional damage (heart attack, vice, widening of the cavities, the presence of additional abbreviations).
2. Auscultation. Listening to the knocking of the heart was the most ancient way to reveal his diseases. Experienced doctors using only this method can reveal the majority of structural and functional pathologies.
3. Ultrasonography. Allows you to see the structure of the chambers of the heart, the distribution of blood, the presence of defects in the muscle and many other nuances that help to diagnose. The method is based on the fact that ultrasonic waves are reflected from solids (bones, muscles, parenchyma of organs) and freely pass through the liquid.

Pathology of the heart

Like in any other organ, in the heart with age, pathological changes accumulate, which provoke the development of diseases. Even with a healthy lifestyle and constant health control, no one is immune from cardiovascular problems. Pathological processes can be associated with a violation of the function or structure of the organ, capture one, two or three of its membranes.

There are the following nosological forms of pathologies:

- disturbances of rhythm and electrical conduction of the heart (extrasystole, blockade, fibrillation);

- Inflammatory diseases: endo-, myo-, peri-, pancarditis;

- Acquired or congenital malformations;

- hypertension and ischemic lesions;

- Vascular disease;

- pathological changes in the wall of the myocardium.

The latter kind of pathology needs to be disassembled in more detail, since it has a direct relationship to the chambers of the heart.

Dilatation of heart chambers

Over time, the myocardium, which forms the walls of the chambers of the heart, can undergo pathological changes, such as excessive stretching or thickening. This is due to the failure of compensatory mechanisms that allow the body to work with significant overloads (hypertension, increased blood volume or thickening).

The causes of dilated cardiomyopathy are:

1. Infections of various etiologies (fungi, virus, bacteria, parasites).
2. Toxins (alcohol, drugs, heavy metals).
3. Systemic diseases of connective tissue (rheumatism, systemic lupus erythematosus).
4. Tumor of the adrenal glands.
5. Hereditary muscular dystrophy.
6. The presence of metabolic or endocrine diseases.
7. Genetic diseases (idiopathic).

Ventricular expansion

The main cause of expansion of the cavity of the left ventricle is its overflow with blood. If the semilunar valve is damaged, or the ascending part of the aorta is narrowed, the heart muscle will need more time and effort to expel the fluid into the systemic pathway. Part of the blood remains in the ventricle, and over time, it stretches. The second reason can be an infection or pathology of the muscle fibers, because of which the wall of the heart becomes thinner, becomes flabby and is not capable of contraction.

The right ventricle can grow in size due to problems with the valve of the pulmonary artery and increase pressure in the small circle of the circulation. When the vessels of the lungs are too narrow, some of the blood from the pulmonary trunk returns to the ventricle. At this moment, a new portion of fluid comes from the atrium and the walls of the chamber are stretched. In addition, some people have congenital defects of the pulmonary artery. This leads to a constant increase in pressure in the right ventricle and an increase in its volume.

Atrial expansion

The cause of enlargement of the left atrium is the pathology of valves: atrioventricular or semilunar. In order to push blood into the ventricle through a small hole, a lot of strength and time is needed, so some of the blood remains in the atrium. Gradually, the amount of residual fluid increases, and a new portion of blood stretches the walls of the heart chamber. The second cause of enlargement of the left atrial walls is ciliary arrhythmia. In this case, the pathogenesis is not fully understood.

The right atrium expands in the presence of pulmonary hypertension. When the vessels of the lungs narrow, the probability of a reverse transfer of blood into the right ventricle is great. And since it is already filled with a new portion of liquid, the pressure on the walls of the chamber increases. The atrioventricular valve does not stand up and is turned out. So the blood gets back to the atrium. In the second place are congenital heart defects. In this case, the anatomical structure of the organ is disturbed, therefore it is possible to communicate between the two atria and mix blood. This leads to overstretching of the walls and their persistent expansion.

Expansion of the aorta

Aneurysm of the aorta can be a consequence of the expansion of the cavity of the left ventricle. It arises in the place where the wall of the vessel is most thinned. Increased pressure, as well as rigidity of surrounding tissues due to atherosclerosis, increase the load on the untenable parts of the vascular wall. A saccular protrusion forms, which creates additional swirls of blood streams. Aneurysm is dangerous because of a sudden rupture and internal bleeding, as well as a source of blood clots.

Treatment of dilation

Traditionally, the therapy is divided into medicamental and surgical. Since it is not possible to reduce stretched heart chambers with pills, the treatment is aimed at the etiologic factor: inflammation, high blood pressure, rheumatism, atherosclerosis or lung diseases. Patients should lead a healthy lifestyle and follow the doctor's recommendations. In addition, the patient is medicinally diluted with blood, which facilitates its passage through the altered chambers of the heart.

Surgical methods include the implantation of a stimulant, which will help to effectively reduce the stretched wall of the heart.

Prevention

In order to prevent the development of myocardial pathology, it is necessary to follow the elementary rules:

- abandon bad habits (tobacco, alcohol);

- to observe the mode of work and rest;

- Healthy food;

Returning to our questions: How many cameras are in the heart of a person? How does blood flow through the body? What nourishes the heart? And how does it all work? We hope that after reading the complex anatomy and physiology of the body has become a little clearer.