The cardiovascular system consists of the heart and the blood vessels. It is responsible for maintaining blood circulation in the body.
The cardiovascular system consists of the heart (lat. Cor) and the blood vessels. The blood circulation is formed by two successive circuits, the body and the pulmonary circulation. The body's circulation (also known as the "great circulation") distributes the oxygen-rich blood throughout the body from the left ventricle. The oxygen-poor blood is returned to the heart. The pulmonary circulation leads the oxygen-poor blood to the lungs and the oxygen-rich blood back to the heart.
The circulation of the body is also called "great circulation". The left atrium collects the oxygen-rich blood. The blood flows through the mitral valve into the left ventricle. From there, the oxygen-rich blood is pumped through the aortic valve into the aorta. The arteries transport the oxygen-rich blood through the body. During this process, the oxygen exchange in the blood takes place. The blood releases the fresh oxygen and absorbs carbon dioxide in return. After the oxygen exchange in the capillaries, the oxygen-poor blood is returned to the heart through the veins. There it arrives at the right atrium of the human body.
The pulmonary circulation, also known as "small circulation", begins in the right atrium of the heart. This is where the oxygen-poor blood, which has returned from the body's circulation, collects. The carbon-enriched blood flows through the tricuspid valve into the right ventricle and is pumped through the pulmonary valve into the pulmonary artery. This is how the blood reaches the lungs. In the lung, the alveoli are surrounded by capillaries, which enables gas exchange. The blood is enriched with oxygen and the carbon dioxide leaves the blood. The oxygen-rich blood is then transported through the pulmonary vein to the heart and enters the left atrium.
Low pressure system
The low pressure system of the human body includes the small circulation (pulmonary circulation), the capillaries, the venous vessels, the right heart and the left atrium as well as the left ventricle during diastole. The pressure in these vessels is significantly lower, which means that the blood pressure in the pulmonary circulation is only 20/8 mmHg. The low pressure system contains about 85% of the total human blood.
High pressure system
The high pressure system includes the left ventricle during systole, as well as the arterial vessels in the large circulation. There the blood pressure is approximately 120/70 mmHg. The body's high-pressure system contains about 15% of all human blood.