Liver: lobule, acinus, hepatocytes, sinusoids, Kupffer cells !
- Organ
The liver is built of cords of cells that blood flows past slowly; where a cell sits in that flow decides what it does and what can hurt it.
Updated 2026-11-01
See it in 3D: Liver
What it is
Hepatocytes form plates between sinusoids that carry mixed portal and arterial blood toward a central vein. This can be drawn as a hexagonal lobule (central vein in the middle, portal tracts at the corners) or as the acinus, a functional unit divided into zones 1 to 3 by distance from the portal tract. Zones explain why ischemia, drugs, viruses and iron injure different parts of the liver, and the space of Disse explains cirrhosis.
Structure
- Portal tract (portal triad): a branch of the portal vein, a branch of the hepatic artery and a bile duct, plus lymphatics, in connective tissue.
- Hepatocytes: large polygonal cells with eosinophilic cytoplasm, often two nuclei, rich in mitochondria, smooth endoplasmic reticulum and glycogen.
- Sinusoids: wide capillaries with fenestrated endothelium and no continuous basement membrane.
- Space of Disse: the gap between endothelium and hepatocytes, with microvilli of hepatocytes and stellate (Ito) cells that store vitamin A.
- Kupffer cells: resident macrophages inside the sinusoids.
- Bile canaliculi: tiny channels between neighbouring hepatocytes, sealed by tight junctions; bile flows toward the portal tract, opposite to blood.
Liver zones 1–3 (acinus)
| Zone | Position | Oxygen | Main activities | Typical injury |
|---|---|---|---|---|
| Zone 1 | Periportal, next to the portal tract | Highest | Oxidative metabolism, gluconeogenesis, bile formation | Viral hepatitis, early iron in hemochromatosis |
| Zone 2 | Middle | Intermediate | Mixed | Yellow fever (midzonal necrosis) |
| Zone 3 | Pericentral (centrilobular), next to the central vein | Lowest | Cytochrome P450 drug metabolism, fat synthesis | Ischemia, acetaminophen, alcohol, congestion |
Markers
- Reticulin (collapse, plate thickness)
- Masson trichrome (fibrosis)
- PAS (glycogen)
- Perls Prussian blue (iron)
Clinical notes
- Cirrhosis: activated stellate cells turn into myofibroblasts and lay down collagen in the space of Disse, forming fibrous bands around regenerative nodules.
- Zone 3 is the first to die in shock and in heart failure (nutmeg liver) because it receives the least oxygen.
- Yellow fever, endemic in parts of Colombia, causes midzonal necrosis with Councilman bodies (apoptotic hepatocytes).
Test yourself
Think of the answer, then tap the question to see it.
Which acinar zone is most sensitive to ischemia and why?
Zone 3 (pericentral), because blood reaches it last, after zones 1 and 2 have taken most of the oxygen.
What three structures make up the portal triad?
A branch of the portal vein, a branch of the hepatic artery and a bile duct.
Which cell in the space of Disse stores vitamin A and causes fibrosis when activated?
The hepatic stellate (Ito) cell, which becomes a collagen-producing myofibroblast.
In which direction does bile flow relative to blood in the lobule?
Opposite: blood runs from the portal tract toward the central vein, bile runs in canaliculi toward the portal tract.
See it in 3D
The structures of Durgical's 3D anatomy where it is found.
Related
Related conditions
Microorganisms
Educational content on normal microscopic structure and its clinical relevance; no substitute for studying slides or for a health professional's advice.
Sources: 23.6 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder - Anatomy and Physiology 2e | OpenStax (OpenStax (Rice University), 2022); Microscopic anatomy of the liver (Clinical Liver Disease (Wiley), via PubMed Central, 2013); Accessory Organs | SEER Training (National Cancer Institute (SEER Training), 2026).
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Representative model, for educational purposes only.