what is the umbilical cord attached to

The umbilical cord is a tube-like structure that connects the developing fetus to the placenta. It is composed of two small arteries and one larger vein, which are surrounded by a gelatin-like extracellular matrix known as Wharton’s jelly. The umbilical vein carries oxygenated, nutrient-rich blood from the placenta to the fetus, while the umbilical arteries carry waste from the fetus back to the placenta. The umbilical cord is not directly connected to the mothers circulatory system, but instead joins the placenta, which transfers materials to and from the maternal blood without allowing direct mixing. The umbilical cord starts to form at about 4 weeks of pregnancy and usually grows to be about 50 to 60 centimeters in length, 2 centimeters in diameter, with up to 40 helical turns. The umbilical cord is cut soon after birth, and the remaining umbilical cord stump will dry and fall off one to three weeks after birth.