Diagrammatic illustration of microscopic canaliculi, the first components of the intrahepatic biliary tree. Bile flows from canaliculi into cholangioles (minute bile ductules lined by cuboidal relative undifferentiated biliary epithelium that have a basement membrane but no designated capillary). These merge into interlobular bile ducts, accompanied by a branch of the hepatic artery and portal vein, and then into progressively larger ducts until hepatic ducts form.