In ductus venous, the fetal blood from the placenta reaches to the liver through
when there is an increase in placental circulation, to facilitate the rapid transpo of blood through the liver ,a large passage is formed between left umbilical vein and right hepato cardiac channel.This passage is called ductus venosus REFERENCE: TEXTBOOK OF CLINICAL EMBRYOLOGY... VISHRAM SINGH SECOND EDITION....PAGE NO:241
Poal vein
Right umbilical vein
Inferior vena cava
Left umbilical vein
General anatomy