The hepatic functional unit commonly shown as the classic hepatic lobule: hexagonal, with portal triads (artery, portal vein, bile duct) approximately positioned at the corners, and a central draining vein.
Blood flows from the periphery of the lobule, supplied by portal and arterial vessels, centrally toward the draining vein in the following order:
- zone 1 (periportal)
- zone 2 (intermediate)
- zone 3 (central, perivenular)
Stages of fibrosis in hepatitis:
- F0 (not shown) - no fibrosis
- F1 - fibrous expansion of portal triad
- F2 - fibrous septa extending from portal triad
- F3 - bridging fibrous septa extending from portal triad to central vein
- F4 - cirrhosis
Case Discussion
The specific histologic patterns of fibrosis vary according to the etiology. The pattern depicted here is classic for fibrosis induced by chronic viral hepatitis.
Alcoholic and adult non-alcoholic steatohepatitis begin with fibrosis adjacent to central vein, progressing in perisinusoidal pattern, eventually forming bridging septa and at end-stage often indistinguishable from viral hepatitis pattern (not shown).
Attribution
Portion of this image uses an image from "Human Physiology", Luciani, Luigi, 1842-,Welby, Frances A. (Frances Alice),Camis, Marie,Holmes, Gordon, Sir, 1876-1965,Pembrey, M. S. (Marcus Seymour), 1868-1934. https://archive.org/stream/humanphysiology02luci/humanphysiology02luci#page/133/mode/1up
The copyright is in the public domain because it has expired.