Figure 19-4 Relationship of branches of the portal vein (PV), hepatic artery (HA), and bile duct (BD). Notice the peribiliary capillary plexus that envelops the bile ducts. These three structures constitute a portal triad, which is a transverse section of a portal canal. (Reprinted with permission from Jones AL: Anatomy of the normal liver. In Zakim D, Boyer T [eds]: Hepatology: A Textbook of Liver Disease, 3rd ed. Philadelphia, WB Saunders, 1996, p 3.)