[Anatomy and physiology of the liver secretory apparatus]

Bile secretion by the liver is thoroughly reviewed on its histologic and functional aspects. Regarding biliary flux, it is quantified as dependent or independent from bile acids. The mechanisms of excretion of other compounds like organic anions, cholesterol and phospholipids, are described. Such aspects allow the classification of intrahepatic cholestasis, based on their mechanisms, which can encompass the following: 1) decreased bile acid synthesis; 2) qualitative changes of bile acids; 3) enzymatic changes of the canalicular membrane; 4) changes in the permeability of the canalicular membrane; 5) dysfunction of the contractile microfilaments of the hepatocyte.