The Vena Cava carries de-oxygenated blood from the body to the right-side of the heart. The Pulmonary Artery then carries de-oxygenated blood from the right side of the heart to the lungs to get oxygenated. Once oxygenated, the blood returns from the lungs to the left-side of the heart through the Pulmonary Veins. Oxygenated blood is then pumped out of the left-side of the heart to the body through the Aorta. This answer would clearly demonstrate an understanding of flow through the heart as well as sufficient knowledge of anatomy for a GCSE student. Once mastered, this could be further developed by discussing the atria and ventricles of the heart and the valvular structures.