What is the blood circulation process throughout the body?

The blood in the body is constantly flowing, providing the body with oxygen and nutrients, which makes the body healthier. However, some people are not very clear about how the blood circulates in the body, but they are very interested and want to learn more. So the editor shares the blood circulation process throughout the body below, hoping to be helpful to those who are interested.

Systemic circulation (macrocirculation): When the ventricles contract, fresh blood (arterial blood) containing oxygen and nutrients flows from the left ventricle into the aorta, and then along the arterial branches at all levels to reach the capillaries throughout the body. Here, the blood exchanges substances with the surrounding cells and tissues. The nutrients and oxygen in the blood are absorbed by the cells and tissues, and their metabolic products and carbon dioxide enter the blood. The blood changes from bright red arterial blood to dark red venous blood. It then flows through veins at all levels and finally returns to the right atrium through the superior and inferior vena cava. The main characteristics of systemic circulation are: long distance, wide range of flow, nourishing all parts of the body with arterial blood, and transporting its metabolic products back to the heart.

Pulmonary circulation (small circulation): venous blood returning to the heart from the systemic circulation enters the right ventricle from the right atrium. When the ventricle contracts, blood is ejected from the right ventricle, enters the lungs through the pulmonary artery, and then enters the capillary network around the alveoli through the branches of the pulmonary artery. Through the capillary walls and the extremely thin alveolar walls, the blood exchanges gases with the air in the alveoli, expelling carbon dioxide and inhaling fresh oxygen, turning venous blood into oxygen-rich arterial blood, which then leaves the lungs through the pulmonary veins and is injected into the left atrium. Blood flows from the left atrium into the left ventricle. The characteristics of pulmonary circulation are: short distance, passing only through the lungs, and its main function is to convert venous blood into oxygen-rich arterial blood.

There are mainly two types of blood circulation in the body. One is the systemic circulation, also known as the large circulation, in which arterial blood circulates to nourish various parts of the body. There is also the pulmonary circulation, which is the small circulation, which is the circulation of venous blood. Its main function is to convert venous blood into arterial blood and then participate in the systemic circulation. These cycles are in motion all the time, which can make the body healthier.