Blood flow refers to the movement of blood through the circulatory system, which includes the heart, arteries, veins, and capillaries. The heart pumps oxygen-rich blood from the left side to the body through the arteries, while oxygen-poor blood returns to the heart through the veins. This process is essential for delivering oxygen and nutrients to cells and removing waste products like carbon dioxide. The capillaries, tiny blood vessels, facilitate the exchange of these substances between blood and tissues. Proper blood flow is crucial for maintaining overall health and supporting bodily functions.