The cardiovascular system consists of the heart, blood vessels, and blood. It functions to transport nutrients, gases, hormones, and waste products throughout the body. The heart pumps oxygen-rich blood through arteries and oxygen-poor blood returns via veins. Blood flows through a closed circulatory loop, being pumped from the heart through arteries, passing through capillaries where gas exchange occurs, and returning to the heart via veins. The document provides details on the components, circulation patterns, and clinical relevance of the cardiovascular system.