Liver Lobule

Description

Radiating hepatocyte plates (cords) converge on a centrally placed terminal hepatic venule (central vein), while the lobule’s periphery is organized into six portal tracts at the corners of a hexagonal unit. Each portal triad logically includes a branch of the portal vein, a branch of the hepatic artery, and an interlobular bile duct, set in connective tissue and positioned peripheral to the sinusoids that run centripetally toward the central vein. Sinusoidal channels course between the hepatocyte cords from portal to central, placing Kupffer cells and the space of Disse in the expected interface between blood and parenchyma. Spatially, blood flows from the lobular periphery to the center, while bile flows in the opposite direction via canaliculi toward the bile ductules. That countercurrent arrangement is the teaching point, and it maps cleanly onto clinical patterns of hepatic injury. Zone 3 hepatocytes, adjacent to the central vein, see the lowest oxygen tension and are the first to show centrilobular necrosis in ischemic hepatitis and in congestive hepatopathy from right-sided heart failure. The same pericentral region is also where CYP450 activity concentrates, explaining why acetaminophen toxicity classically targets centrilobular hepatocytes, while cholestatic processes localize to the portal tracts and bile ducts at the lobule’s edge. Short and memorable. Use this illustration to anchor lectures on liver histology, portal triad anatomy, and hepatic microcirculation in preclinical anatomy and pathology courses, or as a figure for hepatology chapters discussing zonation, ischemic patterns, and drug-induced liver injury. It also supports surgical and radiology teaching on portal inflow versus hepatic venous outflow when correlating lobular structure with segmental vascular anatomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.