Cardiovascular system – one of the major systems of the body, ensuring its vital activity the cardiovascular system circulates blood in the human body. Blood with oxygen, hormones and nutrients is carried through the vessels of the body. Along the way, she shares this wealth with all organs and tissues. Then takes away all that is left of metabolism for further recycling.
Blood circulates through the heart. It is rhythmically reduced as a pump, driving the blood through the blood vessels and providing all organs and tissues with oxygen and nutrients. A living motor is a tireless worker, in one minute the heart pumps about 5 liters of blood through the body, in an hour – 300 liters, in a day runs 7 000 liters.
Blood flowing through the cardiovascular system can be compared to an athlete who runs at different distances. When it passes through the small (pulmonary) circle of blood circulation – it is a sprint. A large circle – this is a marathon. These circles Englishman William Harvey described it in 1628. During the big circle blood runs up on all body, without forgetting to provide it with oxygen and to take away carbon dioxide. During this race arterial blood becomes venous.
The small circle of blood circulation is responsible for the flow of blood into the lungs, where it without regret breaks up with carbon dioxide and takes oxygen. Ends small circle in the left atrium. From there, the blood returns to the great circle.
Blood vessels are like water pipes. Everyone has a role in the body. Through the arteries the blood runs from the heart to the organs, through the veins back to the heart, and the thinnest vessels – capillaries – bring blood to the tissues.
No cell can do without nutrients and oxygen. Delivery is carried out by the arteries. They generously carry oxygen-rich blood throughout the body. When breathing, oxygen enters the lungs, where it is already waiting for red blood cells. Then begins the rapid journey of oxygen through the body. First to the heart, then in a large circle of blood circulation to all parts of the body. There, the blood changes oxygen to carbon dioxide and returns to the heart with a sense of accomplishment. A live motor pumps it back into the lungs, which take the carbon dioxide and give off the oxygen, and so on endlessly. And then there are the pulmonary artery of the pulmonary circulation, they are in the lungs and the blood, poor in oxygen and rich in carbon dioxide enters the lungs where gas exchange occurs. Then this blood through the pulmonary veins returns to the heart.
Blood with carbon dioxide and metabolic products from the capillaries enters the veins first, and on them moves to the heart. Valves, which are almost all veins, make the movement of blood one-way.
Even in the small circle of blood circulation there are so-called pulmonary veins. According to him, the blood rich in oxygen flows from the lungs to the heart.
The blood coagulation system is designed to stop bleeding as quickly as possible in case of any injury or wound. A key role in blood clotting is played by platelets, which are activated when the walls of blood vessels are damaged, thickening blood, as well as blood clotting factors that are activated in trauma and other pathological conditions. Hemostasis system is a biological system of the body, the function of which is to preserve blood in the vessels, prevent bleeding and restore blood flow when the vessel is clogged with a thrombus.