Refer to sinus venosus in development of heart:
- Vitelline veins – drain blood from yolk sac, enter via yolk sac stalk
- Umbilical vein – oxygenated blood from placenta, divides into right and left branch and enters via umbilical cord
- Cardinal veins – body of embryo:
- Anterior cardinal veins – drain head and neck and upper limbs
- Posterior cardinal veins – drain lower limbs
- Common cardinal vein – branches into anterior and posterior cardinal veins
- Subcardinal veins – anastomose infront of aorta
- Supracardinal veins – dorsilateral to aorta
- Azygous cardinal veins – dorsilateral to aorta



Development of Inferior Vena Cava:
- Right vitelline vein
- Intersubcardinal anastomosis
- Right supracardinal vein
- Iliac anastomosis
Anomalies of IVC:
- Forms on left side instead of right due to persistent left veins mentioned above
- Double IVC – persistence of both
- Absent IVC – Lower body drained by azygous vein
Development of renal veins:
Right – Right metanephric vein
Left – Left metanephric vein and intersubcardinal anastomosis (since its longer than right)