Heart

Heart represents the hollow muscular body having the cone-shaped form. Its main function is pumping of the blood coming to it on venous trunks in an artery. Relaxation of a muscle of heart is called a diastole, and reduction – a systole.

Heart structure

Heart is located in the left part of a thorax. Outside of it covers the pericardium forming a cordial bag in which a small amount of serous liquid contains. The middle muscular part of heart is called a myocardium. Inside the cardial cavity by means of partitions is divided into four cameras: two auricles and two ventricles. Blood comes to the left auricle on pulmonary veins, and in right on venas cava. The left ventricle leaves the ascending aortic arch, and from right – the pulmonary arteries forming pulmonary a trunk. In the camera of heart are covered with extremely smooth cover – an epicardium.

The right auricle and left ventricle close a big circle of blood circulation, and the left auricle and a right ventricle – a small circle.

Heart structure in the right and left department variously. So, for example walls of a right ventricle are almost three times thinner, than a left ventricle. It is connected with the fact that at reduction of the last blood is pushed out in a big circle of blood circulation and goes to all bodies and body tissues. In addition resistance and pressure in a big circle are much higher, than in small.

Valve device of heart

The structure of heart is unique since blood in it flows only in one direction. It is provided with its valve device. Valves in the fullness of time open, passing a blood flow, or are on the contrary closed, interfering with the return current (regurgitation).

Between the left ventricle and an auricle the double-wing (mitral) valve is located. It has two shutters. At the time of its opening blood from the left auricle through an atrioventricular opening comes to a left ventricle. At reduction (systole) of a left ventricle of a shutter of the valve are closed, and blood directs in an aorta.

The three-leaved or tricuspid valve is located between the right ventricle and auricles. At the time of its opening blood freely passes from the right auricle in a right ventricle. Shutters of this valve are closed at the time of a systole of a right ventricle. As a result of it blood cannot back come to an auricle and the trunk is pushed out in pulmonary.

At the very beginning of a pulmonary trunk one more valve which function is prevention of the return blood flow in a right ventricle during its diastole is located.

The entrance to an aorta closes the aortal valve having three semi-lunar shutters. It opens at the time of a systole of a left ventricle and is closed at its diastole.

Many heart troubles are caused by pathology of its valve device.

Blood supply of heart

Directly two coronary (coronal) arteries depart from an aorta. They disperse on a set of branches which like a wreath braid all heart, providing intake of oxygen and nutrients to each its cell. Through coronary arteries there passes the fifth part of everything of the blood volume which is thrown out in an aorta.

Regulation of cardiac performance

Reductions and relaxations of heart are regulated by the potassium ions which are contained in blood and calcium, and also an endocrine and nervous system. The nervous system is directly involved in regulation of force and heart rate. The parasympathetic nervous system weakens effort of reductions, and sympathetic on the contrary strengthens them.

The endocrine system influences cardiac performance by means of hormones which can lead to change of heart rate, their strengthening or easing. For regulation of action of the heart adrenal hormones – acetylcholine and adrenaline which action is similar to impact on a myocardium of a parasympathetic and sympathetic nervous system have the greatest value.

Heart troubles

In recent years around the world cardiovascular diseases mortality grows. All heart troubles, depending on the reason and the nature of their emergence, can be divided into several groups conditionally:

• Functional;
• Inborn;
• Atherosclerotic and hypertensive;
• Syphilitic;
• Rheumatic.

In addition there is a number of heart troubles which do not get to the listed above categories and it is necessary to tell about them separately. Treat them:

• Acute dilatation (expansion) of heart. This pathology results from the expressed weakness of a myocardium and an overload of departments of heart in the large volume of blood;
• The atrial flutter – consists in the accelerated regular reduction of auricles behind which ventricles do not manage to be reduced;
• Fibrillation of auricles – at this state is observed the chaotic accelerated reduction of separate muscle fibers of auricles therefore the full-fledged systole is not observed. Fibrillation of auricles is observed against the background of heart failure;
• Bouveret's disease – periodically arising attacks of sharply speeded up reductions of heart;
• The thrombosis of coronal vessels arising against the background of atherosclerosis;
• Myocardial infarction;
• The heart failure which is a final outcome of any heart trouble.

Diagnosis of heart troubles

The modern medicine has great opportunities for carrying out exact and timely diagnosis of heart troubles. Among tool methods in cardiology X-ray, electrophysiologic and electrocardiographic inspections, catheterization of vessels of heart, an echocardiography, a positron and issue and magnetic resonance tomography are most often used. Diagnosis of heart troubles is accompanied by insignificant risk which increases at increase in severity of a disease and technical complexity of the procedure.

Cardiology: treatment of heart

Cardiologists are engaged in therapy of heart diseases. Treatment of heart can be conservative or surgical. An operative measure is shown at numerous defects of the valve device. In this case perform reconstructive operations or replace worn-out valves with artificial. Surgeries carry out also at a row inborn heart diseases.

Conservative treatment of heart is carried out in case of arrhythmias, coronary heart disease, heart failure. At inefficiency of conservative therapy there are indications to an operative measure.