New data on the process of circulation and blood oxygenation in the lungs under physiological conditions.

Blood flow through the human lungs weighing 600 g is about 5 to 6 liters per minute. Blood capacity of human lung is about 500 ml. Therefore, 500 ml blood is oxygenated for 5 sec. Questions arise how such a large volume of blood passes through such a small mass of the lungs and what causes very rapid blood oxygenation. Since the structure of the lungs in mammals is almost the same, the work was carried out on rats (in rats 20-22 ml of blood per minute passes through the lungs weighing 1.5-2.0 g). Intensive blood circulation was proved to be linked with a large diameter pulmonary arterioles and high blood flow velocity in them. The oxygenation rate is explained by special structure of the alveoli and special blood flow conditions, which creates ideal conditions for oxygen diffusion.