Washington Master Esthetics Practice Exam

The heart is considered the central organ of the circulatory system because it is responsible for pumping blood throughout the body. This process supplies oxygen and nutrients to tissues and helps remove waste products. The heart functions as a crucial hub, coordinating the flow of blood through two primary circuits: the pulmonary circuit, which transports blood to and from the lungs for oxygenation, and the systemic circuit, which delivers oxygen-rich blood to the rest of the body.

The other options play supportive but less central roles in the circulatory system. The liver processes nutrients and detoxifies the blood but is not involved in the actual circulation. The lungs are essential for gas exchange, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled, but they do not pump blood. The kidneys filter blood to remove waste and regulate fluid balance but also do not have a primary role in driving circulation.