Normal Fetal Vascular System

1. Amniotic cavity

2. Amnion

3. Heart

4. Aortic sac

5. Aortic arches

6. Sinus venosus

7. Anterior, posterior and common cardinal veins

8. Dorsal intersegmental arteries

9. Aorta

10. Umbilical arteries

11. Umbilical cord

12. Umbilical vein

13. Vitelline artery

14. Vitelline vein

15. Yolk sac