Liver segment
anatomical unit of liver
A liver segment is one of eight segments of the liver as described in the widely used Couinaud classification (named after Claude Couinaud) in the anatomy of the liver. This system divides the lobes of the liver into eight segments based on a transverse plane through the bifurcation of the main portal vein, arranged in a clockwise manner starting from the caudate lobe.
Couinaud segments
There are four lobes of the liver. The Couinaud classification of liver anatomy then further divides the liver into eight functionally independent segments. Each segment has its own vascular inflow, outflow and biliary drainage. In the centre of each segment there is a branch of the portal vein, hepatic artery and bile duct. In the periphery of each segment there is vascular outflow through the hepatic veins. The division of the liver into independent units means that segments can be resected without damaging the remaining segments. To preserve the viability of the liver following surgery, resections follow the vessels defining the peripheries of each segment. This means that resection lines parallel the hepatic veins, leaving the portal veins, bile ducts, and hepatic arteries intact.
Begin with the source’s own compact description: “Liver segment” is anatomical unit of liver. The dossier treats that line as a proposition to test through Liver, segment and anatomical, not as a finished interpretation.
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This entry incorporates text from “Liver segment” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.