Inferior vena cava
From Free net encyclopedia
Current revision
Template:Infobox Vein The inferior vena cava (or IVC) is a large vein that carries de-oxygenated blood from the lower half of the body into the heart. It is formed by the left and right common iliac veins and transports blood to the right atrium of the heart. It is a retroperitoneal structure, meaning it is posterior to the abdominal cavity, and runs along side of the vertebral column on its right side.
The IVC anastomoses with the azygos vein system (which runs on the left side of the vertebral column) and the venous plexuses next to the spinal cord. It drains the lower limbs, perineum and pelvic structures, the retroperitoneal structures (e.g. kidneys) and the digestive organs (via the hepatic veins).
The vein that carries de-oxygenated blood from the upper half of the body is the superior vena cava.
Contents |
Pathologies associated with the IVC
Health problems attributed to the IVC are typically associated with it being compressed; it very rarely ruptures because it has a low intraluminal pressure. Sources of (external) pressure are an enlarged aorta (abdominal aortic aneurysm), a fetus (pregnancy) and abdominal maligancies, such as colorectal cancer, renal cell carinoma and ovarian cancer. Since the inferior vena cava is primarily a right-sided structure, unconconscious pregnant females should be turned on to their left side (the recovery position), to relieve pressure on it and facilitate venous return. In rare cases, straining associated with defecation can lead to restricted blood flow through the IVC and result in syncope (fainting).<ref>Brophy CM, Evans L, Sumpio BE. Defecation syncope secondary to functional inferior vena caval obstruction during a Valsalva maneuver. Ann Vasc Surg. 1993 Jul;7(4):374-7. PMID 8268080.</ref>
Occlusion of the IVC is rare, but considered life-threatening and is an emergency. It is associated with deep vein thrombosis, IVC filters, liver transplantation and instrumentation (e.g. catheter in the femoral vein).<ref>Geehan DM, Inferior Vena Caval Thrombosis, emedicine.com, URL: http://www.emedicine.com/med/topic2718.htm, Accessed: August 3, 2005.</ref>
Embryology
In the embryo, the IVC and right atrium are separated by the Eustachian valve, also known in Latin as the valvula venae cavae inferiore (valve of the inferior vena cava). In the adult, this structure typically has totally regressed or remains as a small endocardial fold.<ref>Yavuz T, Nazli C, Kinay O, Kutsal A. Giant eustachian valve with echocardiographic appearance of divided right atrium. Tex Heart Inst J. 2002;29(4):336-8. PMID 12484622 Full Text.</ref>
See also
References
<references/>
External links
- The Veins of the Lower Extremity, Abdomen, and Pelvis - Gray's Anatomy.
- Eustashian valve - whonamedit.com
| Circulatory system - edit |
|---|
| Blood → Heart → Aorta → Arteries → Arterioles → Capillaries → Venules → Veins → Vena cava → Heart → Pulmonary arteries → Lungs → Pulmonary veins |