So inside developing fetus, there are two important shuns that are used by the circulatory system of that fetus to redirect blood away from the nonfunctional lungs and to the functional organs of that fetus, such as, for example, the brain. Now, these two shuns include the foramen ovaly as well as the ductus arteriosis. So let's briefly discuss how the blood actually actually travels within the heart of that vetus. So we have the inferior venecrava and the superior venecrava. And as the partially oxygenated blood makes its way via these two blood vessels and into the right atrium, once inside the right atrium, that blood goes into the left atrium via the Foramin or valley. And that's because on the right side of the heart, we have a higher pressure than the left side as a result of those nonfunctional lungs.