The heart brings blood from two different locations before pumping it to the body:
From the body: After circulating through the body and delivering oxygen and nutrients to the tissues, the blood returns to the heart through the veins. Deoxygenated blood, which has given up its oxygen and picked up carbon dioxide and waste products, enters the right side of the heart through the superior and inferior vena cava. These are large veins that collect blood from the upper and lower parts of the body, respectively.
From the lungs: The blood that has returned to the right side of the heart is then pumped into the lungs through the pulmonary artery. In the lungs, the blood releases carbon dioxide and picks up fresh oxygen through a process called gas exchange. As a result, the blood becomes oxygenated.
After oxygenation, the blood returns to the left side of the heart through the pulmonary veins. These are unique because they carry oxygenated blood, while other veins in the body generally carry deoxygenated blood. The left side of the heart then pumps the oxygen-rich blood out to the rest of the body through the aorta, the main artery that distributes blood to various organs and tissues.
So, in summary, the heart receives deoxygenated blood from the body through the superior and inferior vena cava and sends it to the lungs through the pulmonary artery for oxygenation. Once oxygenated, the blood returns to the left side of the heart through the pulmonary veins and is then pumped out to the rest of the body via the aorta. This cycle of blood flow is essential for the body's oxygen and nutrient supply and waste removal.