Cardiovascular system: Schematic (English)

The cardiovascular system is divided into two major circuits: pulmonary and systemic. The pulmonary circuit begins in the right ventricle of the heart by carrying deoxygenated blood into the lungs for gaseous exchange and ends by bringing oxygenated blood from the lungs into the left atrium of the heart. The distribution of the blood to the body starts via a systemic circuit that begins with the left ventricle of the heart, which pumps blood through the aorta and systemic arteries to the capillary beds of peripheral tissues and organs. Deoxygenated blood is then drained by the systemic veins of the circuit to superior and inferior vena cava which empty their contents back into the right atrium of the heart.