The heart


The heart (Latin Cardia) pumps blood through our body and thus keeps the blood circulation upright for life. The heart pumps around 5 liters of blood per minute through the body, which corresponds approximately to the total blood volume. It is quite likely that the heart or the heartbeat has been a symbol of life since the earliest beginnings of humanity. And rightly so, because without a heart - at least for humans - no life is possible.
But what exactly does the heart do? Through the contraction of the heart muscle, the heart pumps blood through the main artery into the arteries and arterioles up to the capillaries, the smallest blood vessels in the body. For metabolism, every single body cell requires oxygen. The blood carries the oxygen through the body to the cells, and also transports the waste products (e.g., carbon dioxide) again. Via the veins, the oxygen-poor blood flows back to the heart, is re-enriched in the lungs with oxygen and pumped back through the body. In this way, the cells are not only supplied with oxygen, but also with important nutrients.

Construction / anatomy: heart

The connective tissue heart bag surrounds the entire heart. The outer layer is fused in places with the surrounding tissue, so that the pericardial pouch holds the heart in its approximate position. The inner layer, wetted with a liquid film, protects the heart from contact with other body tissues. Within the pericardium, the heart thus has a certain freedom of movement, without the risk of bumping against other organs.
The blood is collected from the two circulations of blood in the two vessels before it flows into the respective ventricle. Functionally, they are thus to a certain extent the end of the respective cycle
In the right atrium low-oxygen blood flows from the body cycle. The left atrium, he oxygenated blood from the pulmonary circulation flows here
The blood from the appendages flows through the heart valves into the heart chambers. The heart valves prevent the blood from flowing back into the atrium.
The right ventricle is part of the pulmonary circulation and ends in the pulmonary artery. The left ventricle is part of the body circulation and ends in the aorta. In contrast to the other ventricle, the left ventricle is significantly stronger, because the body cycle requires a much higher pressure, because the blood must flow against the force of gravity from below (legs, feet), back up (vena cava). At the pulmonary circulation this way is much shorter.
Also between the right ventricle and the pulmonary artery, as well as between the left ventricle and the aorta, heart valves again prevent a return to the ventricle.
pulmonary artery
The pulmonary artery leads the oxygenated blood to the lungs. In the capillaries of the pulmonary alveoli, the blood finally binds oxygen.
The aorta (main artery) is the largest artery of the body. It leads the oxygen-rich blood from the right ventricle to the subsequent body arteries.
heart valves
Heart valves prevent the return of blood, allowing blood to flow in one direction only. The heart has the following four flaps:
Tricuspid valve (right atrium -> right ventricle of the heart)
Pulmonary valve (right ventricle -> pulmonary artery)
Mitral valve (left atrium -> left ventricle of the heart)
Aortic valve (left ventricle -> aorta)