Figure 9.

The figure illustrates the heterogeneity of the structure and function of the biliary tree and bile duct epithelial cells. Canalicular bile secreted by hepatocytes enters the biliary tree by joining upstream with the canals of Hering. As branches of the biliary tree join, the luminal diameter increases (values in parentheses) and the bile duct epithelial cells become larger. The range of receptors and transporters on medium and large bile duct cells is similar although secretin receptor expression and Cl⁻/HCO₃⁻ exchange activity is greater in the median and large size bile duct cells. Reprinted, with permission, from Ref. (76).