The embryo gets nutrition front he mothers blood with the help of a special tissue called placenta. This is a disc which is embedded in the uterine wall. It contains villi on the embryos side of the tissue. on the mothers side are blood spaces, which surround the villi. This provides a large surface area for glucose and oxygen to pass from the mother to the embryo. the developing embryo will also generate waste substances which can be removed by transferring them into the mothers blood through the placenta.
