Task of the heart valves
The heart has four heart valves, whereby one differentiates between pocket and sail valves. The two sail valves separate the atria of the heart from the ventricles. The so-called tricuspid valve lies between the right atrium and the right ventricle, the mitral valve forms the border between the left atrium and the left ventricle.
These two valves are closed during the tensing phase of the heart and thus prevent the blood in the heart from being pumped backwards. In the relaxation phase, the two sail valves open to allow the ventricles to fill with blood again. The pocket valves separate the heart chambers from the vascular system behind them.
The pulmonary valve lies between the right ventricle and the pulmonary circulation. The aortic valve separates the left ventricle from the circulatory system of the body. Both valves are closed during the relaxation phase, also the filling phase, as the heart chambers fill up.
The tension of the heart causes these valves to be pushed open and the blood enters the circulation. The valves become problematic if they leak. This is then called insufficiency of the heart valve. In addition, a narrowing in the area of the valves can occur, which is called stenosis in the technical language. In both cases the heart has to do more work.
Task of the coronary arteries
The human heart is supplied by two main vessels: the left and the right coronary artery. The coronary arteries, or coronary arteries in technical terms, are responsible for supplying the heart muscle with blood. This ensures that sufficient nutrients and oxygen are transported to the muscle cells.
In addition, the waste products produced by the work of the heart are removed from the muscles. In most muscles, the supplying vessels form many cross connections. This means that even in the event of a blockage in one vessel, the entire muscle continues to be supplied with sufficient blood.
The coronary vessels also form these so-called collateral circulation systems. However, these are not sufficient to supply the heart completely. Therefore, the occlusion of a branch of the coronary vessels leads to a reduced supply of blood to the muscles behind it.
Due to the pumping activity of the heart, the coronary vessels are not supplied with blood all the time. Only in the relaxation phase of the heart does blood enter the vessels. Under stress the heartbeat becomes faster, which also means that the relaxation phase is shortened. This means that the time in which the coronary vessels are supplied with blood is also shorter.
Task of the cardiac septum
The cardiac septum is the part of the heart that lies between the two ventricles. Its first task is therefore to separate the two chambers. Like the outer parts of the heart, the cardiac septum is made up of muscles and, together with the rest of the heart, pumps the blood into the circulation during the contraction phase.
Since the left ventricle has to do considerably more work than the right, the cardiac septum mainly supports the left ventricle in its pumping function. Parts of the excitation conduction system also run through the cardiac septum. The electrical signal runs from the atria to the tip of the heart.