The superior vena cava carries blood from the top portion of the body, and the inferior vena cava carries blood from the lower portion of the body. The left atrium receives blood from the lungs after they have oxygenated the blood. This blood is received through the pulmonary vein . There are 2 pulmonary veins. One flows from the right lung and one flows from the left lung.
Ventricles are the lower chambers.
They receive blood from the atria and push it outward through arteries. Arteries send blood away from the heart. The right ventricle pushes unoxygenated blood to the lungs through the pulmonary artery . There are 2 pulmonary arteries. One flows to the right lung and one flows to the left lung.