Epatociti

Epatociti, also known as hepatocytes, are the main functional cells of the liver. They are large polygonal cells, typically 20–30 μm in diameter, and are frequently binucleate. They form plates one cell thick that radiate from the central vein within hepatic lobules and are separated by narrow sinusoids. The cytoplasm is eosinophilic and rich in mitochondria and endoplasmic reticulum. Bile canaliculi form between adjacent hepatocytes and drain into bile ducts.

Metabolic and synthetic roles: Hepatocytes metabolize carbohydrates, lipids, and proteins; they store glycogen, participate in gluconeogenesis, and contribute to the urea cycle. They synthesize most plasma proteins, including albumin and several coagulation factors, and secrete them into the bloodstream. They also process lipids and cholesterol, produce bile acids, and secrete bile via canalicular transporters.

Detoxification and signaling: Hepatocytes express Phase I and Phase II detoxification enzymes, notably cytochrome P450s, UDP-glucuronosyltransferases, and glutathione-S-transferases, enabling xenobiotic metabolism and conjugation. They conjugate and excrete bilirubin and other metabolites. They respond to hormones with receptor-mediated signaling and produce acute-phase proteins during inflammation.

Microenvironment and regeneration: Hepatocytes receive a dual blood supply from the portal vein and hepatic artery, with sinusoidal exchange enabling nutrient uptake and waste removal. The liver's regenerative capacity allows hepatocytes to proliferate after injury. Chronic damage can lead to steatosis, fibrosis, and cirrhosis.