Refer to sinus venosus in development of heart:

1. Vitelline veins – drain blood from yolk sac, enter via yolk sac stalk
2. Umbilical vein – oxygenated blood from placenta, divides into right and left branch and enters via umbilical cord
3. 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)