ductus arteriosus
small vessel connecting the pulmonary artery with the descending thoracic aorta – allows detour of blood around the lungs and directly into the system
foramen ovale
opening in the septum between the left and right atria – blood bypasses the fetal lungs
ductus venosus
continuation of the umbilical vein under the liver and drains into the inferior vena cava
umbilical vein
returns oxygenated blood from placenta into fetal body through the umbilical cord