Understanding blood flow in the heart and body
The right side of the heart pumps blood to the lungs while the left side pumps blood to the rest of the body. Blood from the body enters the right atrium though the venacava. It then flows into the right ventricle where it is pumped to the lungs through the pulmonary artery. In the lungs, oxygen is loaded onto red blood cells and returns to the left atrium of the heart via the pulmonary artery. Blood then flows into the left ventricle where it is pumped to the organs and tissues of the body. Oxygen is downloaded from red blood cells while carbon dioxide, a waste product of metabolism, is added to be removed in the lungs. Blood then returns to the right atrium to start the cycle again.