Fig. 2. Blood vessels passing through the umbilical cord in a human fetus. (From Quain's Anatomy, vol. 2.) L, liver; K, kidney; I, intestines; U C, umbilical cord; Ua, umbilical arteries. The posterior aorta coming from the heart passes backward and gives rise to the internal iliac arteries, and of these the umbilical arteries are branches. Uv, umbilical vein; this joins the portal vein, passes onward to the liver, breaks up into smaller vessels, which reunite in the hepatic vein; this empties into the posterior vena cava, which carries the blood back to the heart.
