The biliary tree is dividable into extrahepatic and intrahepatic
bile ducts. The gallbladder drains into the
extrahepatic bile duct via the cystic duct. The right and
left hepatic ducts and their first to third branches are
collectively called “hilar and perihilar bile ducts”. The
intrahepatic bile ducts, proximal to the right or left hepatic
duct, are classified as intrahepatic large and small bile
ducts[16]. The former are visible grossly and consist of the
first to third branches of right or left hepatic bile ducts.
Peribiliary glands are physiologically distributed around
the large bile ducts and drain into the duct lumen via their
own conduits. The latter are recognizable microscopically
and consist of septal and interlobular bile ducts. The
interlobular bile ducts are connected to bile ductules.
The septal bile duct is surrounded by a fibrous wall and
is over 100 μm in size while the external diameter of
the interlobular bile duct is less than 100 μm. These two
bile ducts are accompanied by hepatic arterial branches
of similar size while bile ductules or canals of Hering
are located at the periphery of portal tracts and facing
hepatocytes[17].