Oxygen goes into the blood and carbon dioxide is expelled as a waste product. And so that leads us directly into function three, waste product removal or function four, waste product removal. What that basically means is not only carbon dioxide is removed by the placenta from the blood of that embryo but also other byproducts wasteful byproducts such as urea. Uric, acid and creepine are all released by the blood of that fetus and into the blood of the mother. And the blood of the mother eventually dumps those waste products into the kidneys where the kidneys essentially recycle and excrete those waste products to the outside environment. So these are the many important functions of the placenta.