Bile secretion

摘要

The canalicular space forms a tube that is closed at one end near the center of the lobule. Its boundary is the apical 玞analicular? membrane of two or three adjacent hepato-cytes. Bile entering the canalicular space flows toward the portal region where individual canaliculi coalesce and connect through canals of Hering to portal interlobular bile ducts. Canalicular bile flow is enhanced by phasic contractions of the canaliculi in periportal areas. Intrahepatic bile ducts are formed by epithelial cells with histologic features of transporting epithelia including apical microvilli and tight junctions. Bile ducts are in intimate contact with branches of the hepatic artery from which they receive the majority of their blood supply. Intrahepatic biliary cells account for 3 to 5% of the nuclear mass of the liver but the combined length is estimated to be over 1 km in humans.