We have these Corianic villi which are in contact with the mother's blood. And we have these maternal blood vessels, which essentially have ruptured and created the pooling of that blood within the endometrium in our placenta. Now, we also have the Biblical cord, which contains those two blood vessels, the two types of blood vessels. We have the umbilical vein, and we have the umbilical artery. And the umbilical cord also actually contains two types of extra embryonic membranes. It contains the lantos and it also contains the umbilical vesicle, also known as the yolksac.