The cardiovascular system is a complex network that includes the heart, blood vessels, and blood. Its primary function is to transport oxygen, nutrients, hormones, and waste products throughout the body. The heart pumps blood through two main circuits: the pulmonary circuit, which carries blood to the lungs for oxygenation, and the systemic circuit, which delivers oxygen-rich blood to the rest of the body. Blood vessels are categorized into three types: arteries, which carry blood away from the heart; veins, which return blood to the heart; and capillaries, where the exchange of gases and nutrients occurs. This system plays a crucial role in maintaining overall health and supporting bodily functions.