In placental mammals, the umbilical cor (also called the birth cord or funiculus umbilicalis) is the connecting cord between the developing embryo or fetus to the placenta. Developed from the same zygote as the fetus, the umbilical cord normally contains two arteries (the umbilical arteries) and one vein (the umbilical vein), buried within Wharton's jelly. The umbilical vein supplies the fetus with oxygenated, nutrient-rich blood from the placenta. Conversely, the umbilical arteries return the deoxygenated, nutrient-depleted blood.