The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.[1][2]
The inferior vena cava is the lower ("inferior") of the two venae cavae, the two large veins that carry deoxygenated blood from the body to the right atrium of the heart: the inferior vena cava carries blood from the lower half of the body whilst the superior vena cava carries blood from the upper half of the body. Together, the venae cavae (in addition to the coronary sinus, which carries blood from the muscle of the heart itself) form the venous counterparts of the aorta.
It is a large retroperitoneal vein that lies posterior to the abdominal cavity and runs along the right side of the vertebral column.[1] It enters the right auricle at the lower right, back side of the heart. The name derives from Latin: vena, "vein", cavus, "hollow".
Structure
The IVC is formed by the joining of the left and right common iliac veins and brings collected blood into the right atrium of the heart.[1] It also joins with the azygos vein (which runs on the right side of the vertebral column) and venous plexuses next to the spinal cord.
Because the inferior vena cava is located to the right of the midline, drainage of the tributaries is not always symmetrical. On the right, the gonadal veins and suprarenal veins drain into the inferior vena cava directly.[1] On the left, they drain into the renal vein which in turn drains into the inferior vena cava.[1] By contrast, all the lumbar veins and hepatic veins usually drain directly into the inferior vena cava.[1]
Development
In the embryo, the inferior vena cava and right auricle are separated by the valve of the inferior vena cava, also known as the Eustachian valve. In the adult, this valve typically has totally regressed or remains as a small fold of endocardium.[4]
Variation
Rarely, the inferior vena cava may vary in its size and position. In transposition of the great arteries the inferior vena cava may lie on the left.
In between 0.2% to 0.3% of people,[5] the inferior vena cava may be duplicated beneath the level of the renal veins.[6]
Function
The inferior vena cava is a vein. It carries deoxygenated blood from the lower half of the body to the right atrium of the heart.[6]
The corresponding vein that carries deoxygenated blood from the upper half of the body is the superior vena cava.
^ abSusan Standring; Neil R. Borley; et al., eds. (2008). Gray's anatomy : the anatomical basis of clinical practice (40th ed.). London: Churchill Livingstone. ISBN978-0-8089-2371-8.