Inferior vena cava
The inferior vena cava (IVC) is the largest vein of the human body. It is located at the posterior abdominal wall on the right side of the aorta. The IVC’s function is to carry the venous blood from the lower limbs and abdominopelvic region to the heart.
The inferior vena cava anatomy is essential due to the vein’s great drainage area, which also makes it a hot topic for anatomy exams. For that reason, this page will cover the IVC anatomy in a way that’s easy to read and understand.
|Definition and function||The vein that collects deoxygenated blood from the abdomen, pelvis and lower limbs and carries it to the right atrium of the heart|
|Source||Common iliac veins (L5)|
Phrenic, right Suprarenal, Renal, right Testicular (gonadal), Lumbar, common Iliac and Hepatic veins
Mnemonic: Portal System Returns To Liver In Humans
|Clinical relations||Inferior vena cava thrombosis|
The inferior vena cava arises from the confluence of the common iliac veins at the level of L5 vertebra, just inferior to the bifurcation of the abdominal aorta. It then ascends the posterior abdominal wall, to the right side of the aorta and the bodies of the L3-L5 vertebrae. After passing through its fossa on the posterior liver surface, the IVC enters the thorax by traversing the inferior vena caval foramen of the diaphragm.
The tributaries of the IVC correspond to the branches of the abdominal aorta. Note that some professors will want you to know at which vertebral level the IVC gets its direct tributaries, so they are as follows:
- The direct tributaries are the inferior phrenic veins (T8), right suprarenal (L1), renal (L1), right testicular (gonadal) (L2), lumbar (L1-L5), common iliac (L5) and hepatic (T8). If you want an easy way to remember them just memorise the mnemonic ' Portal System Returns To Liver In Humans'.
- Left gonadal and left suprarenal renal veins drain first into the left renal vein
- The veins of the stomach, spleen, pancreas, small and large intestines first empty into the hepatic portal vein. The hepatic portal vein carries this blood to the liver to be processed and detoxified. Then, the blood reaches the IVC through the hepatic veins.
Feel overwhelmed by all of the tributaries to the IVC? We have an article about how to learn anatomy with mind maps to help you learn anatomy more efficiently.
Learn more about the tributaries of the IVC and its anatomy.
The IVC’s function is to convey the blood from the abdomen, pelvis, and lower limbs to the right atrium of the heart. Additional IVC functions are noticeable during some health disturbances, such as hepatic portal vein obstruction or the obstruction of the IVC itself.
Specialized vessels called the portocaval (portosystemic) anastomoses open if the hepatic portal vein is obstructed. The intestinal blood then bypasses the liver and empties into the IVC directly. In cases where the IVC is occluded, the collateral vessels to the superior vena cava open.
Learn more about portocaval anastomoses with our article, then take this specially designed quiz to consolidate everything you’ve learned about the IVC and its tributaries.
Inferior vena cava thrombosis
Thrombosis of the inferior vena cava (IVCT) is a condition in which a blood clot (thrombus) impedes the blood flow through the IVC. The thrombus can be formed within the IVC itself, which is rare, or, more commonly, travel from the deep veins of the legs in a condition called deep venous thrombosis (DVT).
IVC thrombosis may be caused by all the conditions that lead to venous stasis. These include congenital abnormalities of the IVC, immobilization, obesity, pregnancy, sedentary lifestyle, and tumors of surrounding organs. IVCT presents with symptoms of venous obstruction, such as pain and swelling of lower limbs and scrotum. IVCT is diagnosed by ultrasound, CT,and MRI.
Depending on the severity of the condition, the IVCT can be treated by surgical removal of the thrombus, thrombolytic therapy, and anticoagulant therapy. The treatment is necessary to prevent disseminating of the thrombus into the pulmonary circulation (pulmonary thromboembolism), which is an urgent medical condition.