So this is the way that blood circulates inside that developing fetus before the birth of that fetus. So we have three important shunting processes taking place. And the reason we need the shunting processes is because the liver and the lungs are not functional in that developing fetus. So to redirect the blood and conserve that oxygen nutrients, we have the Ductus Venus that redirects the blood and bypasses the liver. And the blood enters the inferior veneca. Now, between the right atrium and the left atrium, we have this small door like structure known as the forayman O'Valley.