The pathway of blood circulation is broken into two different circulatory pathways, states the National Cancer Institute. The pulmonary circuit transports de-oxygenated blood from the right ventricle into the lungs to become oxygenated, while the systemic circuit carries oxygenated blood to the rest of the body.
The systemic circuit and the pulmonary circuit originate in the heart. De-oxygenated blood first enters the heart through the inferior and the superior vena cavae. Next, the blood moves into the right atrium and then flows into the right ventricle. Then, the de-oxygenated blood enters the pulmonary artery and flows into the lungs to become oxygenated. The blood then leaves the lungs and enters the left atrium. It then flows from the left atrium to the left ventricle to the aorta. The aorta pushes the blood out of the heart and sends oxygenated blood through the systemic circulation.