21. All the veins empty into the inferior vena cava at the back of the liver. 22. On the right, the gonadal veins and suprarenal veins drain into the inferior vena cava directly. 23. If the aneurysm stretches too far, it can narrow the opening of the inferior vena cava . 24. This was described in relation to retrocaval ureter ( now renamed as preureteric vena cava ). 25. Implantation involves anastomoses ( connections ) of the inferior vena cava , portal vein, and hepatic artery. 26. Following birth and separation from the placenta, the oxygen content in the inferior vena cava falls. 27. Blockage of the inferior vena cava is rare, and is treated urgently as a life-threatening condition. 28. Blood from here does not flow through the liver prior to entering the inferior vena cava . 29. The bottom evolves into : the inferior valve of the vena cava and the coronary sinus valve. 30. By contrast, all the lumbar veins and hepatic veins usually drain directly into the inferior vena cava .
