Development of the Inferior Vena Cava
The inferior vena cava actually develops from 4 segments! The cardiovascular system starts developing during the 3rd week. In embryonic life, 3 main veins are present in the embryo - the umbilical veins carrying oxygenated blood from the placenta, vitelline veins carrying deoxygenated blood from the umbilical vesicle and common cardinal veins which drain the embryo. Out of the cardinal veins, posterior cardinal veins disappear and subcardinal and supracardinal veins appear and replace them. The IVC forms from 4 different segments of these different vein as shown in the picture above. Hepatic segment - proximal part of right vitelline vein Pre-renal segment - right subcardinal vein Renal segment - subcardinal-supracardinal anastomosis Post - renal segment- right supracardinal vein Image via: https://images.app.goo.gl/kS3e1RjHwtPxwdH59