Answer: 1. right atrium
Blood is transported into the heart via the inferior and superior vena cava — two large veins that pump deoxygenated blood into the heart. The superior vena cava empties this deoxygenated blood into the right atrium, while oxygenated blood is emptied into the left atrium of the heart by the pulmonary vein. From the right atrium, the blood is transported to the right ventricle, and subsequently into the pulmonary artery.