Organ
Hepatic lobule and acinus
Microscopic maps organized around blood and bile flow
High-yield
Sinusoidal blood travels toward central venous outflow; canalicular bile travels toward portal-tract ducts. Acinar zone numbers increase with distance from incoming blood.
Overview
A classic hepatic lobule is organized around a terminal hepatic venule, with portal tracts toward its edges. A portal lobule instead highlights bile drainage to one duct, while an acinus follows the territory supplied by terminal inflow vessels. These models describe the same tissue from different functional perspectives.
Reference facts
- Location
- Microscopic organization throughout hepatic parenchyma; portal tracts contain portal venous and arterial branches, bile ducts, connective tissue and other small structures.
- Parts
- Acinar zone 1 is periportal, zone 2 intermediate and zone 3 pericentral; these zones are functional regions without grossly visible boundaries.
- Blood supply
- Portal venous and hepatic arterial inflow mixes in sinusoids before reaching terminal hepatic venules and larger hepatic veins.
- Relations
- Canaliculi between hepatocytes communicate with canals of Hering and ductules toward portal tracts, separate from the sinusoidal blood pathway.
- Function
- Periportal and pericentral hepatocytes show different metabolic emphases, including oxidative/gluconeogenic activity nearer inflow and substantial xenobiotic metabolism pericentrally.
Clinical correlation
Pericentral zone 3 receives less oxygenated blood than periportal zone 1 and is vulnerable during severe hypoperfusion. Acetaminophen toxicity also commonly produces centrilobular injury, through metabolic mechanisms rather than oxygen supply alone.
Frequently asked questions
Where is the hepatic lobule and acinus located?
Microscopic organization throughout hepatic parenchyma; portal tracts contain portal venous and arterial branches, bile ducts, connective tissue and other small structures.
What does the hepatic lobule and acinus do?
Periportal and pericentral hepatocytes show different metabolic emphases, including oxidative/gluconeogenic activity nearer inflow and substantial xenobiotic metabolism pericentrally.
What are the parts of the hepatic lobule and acinus?
Acinar zone 1 is periportal, zone 2 intermediate and zone 3 pericentral; these zones are functional regions without grossly visible boundaries.
What is the blood supply of the hepatic lobule and acinus?
Portal venous and hepatic arterial inflow mixes in sinusoids before reaching terminal hepatic venules and larger hepatic veins.