The basic process through which blood travels through the heart is known as circulation. Blood is pumped by the heart in a continuous loop, moving through two main circuits: the pulmonary circuit and the systemic circuit. In the pulmonary circuit, deoxygenated blood is sent from the right side of the heart to the lungs for oxygenation. The oxygenated blood then returns to the left side of the heart, where it is pumped out to the rest of the body through the systemic circuit. Efficient circulation is essential for transporting nutrients and oxygen to tissues.