How heart working

The heart is a muscular organ that pumps blood throughout the body. It has four chambers: two atria and two ventricles. Blood low in oxygen returns to the right atrium, then flows to the right ventricle and is pumped to the lungs to get oxygen. Oxygen-rich blood returns to the left atrium, passes to the left ventricle, and is pumped into the body through arteries. The heart's contractions (systole) and relaxation (diastole) create the heartbeat, ensuring blood circulation.