Answer:
Blood (deoxygenated) from the upper parts of the body above the diaphragm collect into the superior vena cava, blood(deoxygenated) from the lower part of the body collect into the inferior vena cava. These two vena cavae empty their contents alongside the coronary sinus (veins from the heart itself) into the right atrium. The blood is then pumped into the right ventricle via the tricuspid valve. From here,blood goes into pulmonary circulation thus,to the Lungs via the pulmonary semilunar valves through the pulmonary arteries. The oxygenated blood returns to the left atrium through the pulmonary veins and is pumped into the left ventricle via the mitral valve. Oxygenated blood is now pumpued under high pressure through the aorta via the aortic semilunar valves into systemic circulation