The movement of blood in the large and small circles of blood circulation. Changes in the composition of the blood in them.

The human circulatory system consists of a large and a small circle. All blood makes a complete bypass of the vessels of the body in just 27 seconds. A small circle takes 6 seconds, and a large one, respectively, 21 seconds. In the pulmonary circulation, erythrocytes cease to retain carbon dioxide and replace these bonds with oxygen ones. In a big circle, the opposite happens. The blood transfers oxygen to the tissues. In this case, bonds with oxygen are replaced by bonds with carbon dioxide. It is formed during the life of cells. For example – in the process of oxidation of substances.