galkanaaltjes

Galkanaaltjes, in Dutch anatomy, refer to the bile canaliculi: microscopic channels in the liver formed by the apical membranes of adjacent hepatocytes. They collect bile produced by hepatocytes and drain it into the intrahepatic biliary system, first through the canal of Hering and then into progressively larger bile ducts within the portal areas.

Anatomy and histology: Each canaliculus is a narrow channel bounded by the opposing hepatocyte membranes and sealed by tight junctions between neighboring cells. The canalicular surface often has a dense brush border of microvilli that increases secretory surface area, supporting the excretion of bile into the canalicular lumen as part of the biliary network.

Physiology and transport: Bile acids and other secretory products are released into the canaliculi by hepatocytes. The canalicular membranes contain transport proteins such as the Bile Salt Export Pump (BSEP, ABCB11) and MDR3 (ABCB4), which drive bile formation by exporting bile acids and phospholipids, respectively. Water follows osmotically, aiding the movement of bile through the network.

Clinical relevance and terminology: Proper function of galkanaaltjes is essential for bile production and liver excretion. Impairment can lead to cholestasis, jaundice, and malabsorption of fats. Drug-induced cholestasis and some congenital cholestatic diseases involve defects in canalicular transporters. The term is used in Dutch-language medical literature and corresponds to the English term bile canaliculi.