Final answer:
The umbilical cord has two arteries that carry oxygen-depleted blood from the fetus to the placenta, and one vein that carries oxygen-rich blood from the placenta to the fetus.
Step-by-step explanation:
The umbilical cord typically contains two arteries and one vein. The umbilical arteries are responsible for carrying blood that is low in oxygen and high in waste from the fetus to the placenta. Here, an exchange with the maternal blood occurs, allowing for the disposal of fetal waste and the replenishment of oxygen and nutrients. Following this exchange, the single umbilical vein carries oxygenated, nutrient-rich blood from the placenta back to the fetus. This circulation is crucial for the development of the fetus during pregnancy, and is severed when the umbilical cord is cut following birth, eventually leading to the formation of the navel.