Hepatocyty

Hepatocyty, or hepatocytes, are the main parenchymal cells of the liver, comprising a large portion of the organ’s mass. They are polygonal cells, typically about 20–30 micrometers in diameter, with a large central nucleus and abundant cytoplasm rich in mitochondria and endoplasmic reticulum. Hepatocytes are arranged in plates one to two cells thick and are separated by fenestrated sinusoids that facilitate exchange with the blood.

In the classic liver lobule, hepatocytes receive blood from the portal triads at the periphery, and blood flows toward a central vein. The bile produced by hepatocytes is secreted into canaliculi formed between adjacent cells and drains into bile ducts within the portal triads. The sinusoids contain Kupffer cells, and the space of Disse lies between hepatocytes and the sinusoidal endothelium where hepatic stellate (Ito) cells reside.

Functions: Hepatocytes carry out most of the liver’s metabolic, synthetic, and detoxification activities. They regulate carbohydrate metabolism via glycogen storage and glucose release, synthesize plasma proteins (including albumin and many clotting factors), and participate in lipid metabolism. They detoxify drugs and xenobiotics through cytochrome P450–mediated reactions, conjugate and excrete bilirubin, and secrete bile acids and other components into bile.

Regeneration and clinical relevance: Hepatocytes have a high regenerative capacity and can proliferate after injury. Damage to hepatocytes from viral hepatitis, alcohol-related disease, or drug-induced injury elevates liver enzymes (ALT, AST) and may progress to inflammation, fibrosis, and cirrhosis if injury persists.