Gallensekret

Gallensekret is a term used to refer to the bile secretion produced by the liver and delivered to the digestive tract through the biliary system. In humans, bile is produced by hepatocytes and secreted into bile canaliculi, then transported via the bile ducts to the gallbladder for storage and concentration between meals. During digestion, the gallbladder contracts and releases bile into the duodenum through the sphincter of Oddi.

Composition: Bile contains bile acids (bile salts), cholesterol, phospholipids, bilirubin, and electrolytes such as bicarbonate. Bile acids are amphipathic molecules that aid fat emulsification and micelle formation; conjugated bile acids are more water-soluble.

Regulation: Secretion is regulated by neural and hormonal signals. Cholecystokinin (CCK) stimulates gallbladder contraction and bile release; secretin stimulates bicarbonate secretion from cholangiocytes; vagal activity also modulates secretion during meals. The enterohepatic circulation recycles most bile acids from the ileum back to the liver, maintaining bile acid pool.

Function: The primary role of gallensekret is to digest fats by emulsification, enabling lipase activity, and to transport waste products like bilirubin for excretion. It also helps detoxify certain compounds and maintains intestinal sterol balance. The flow and composition adjust with diet.

Clinical relevance: Impaired secretion or flow leads to cholestasis; gallstones can form from cholesterol or bilirubin; gallbladder disease can alter bile storage; obstruction causes jaundice and malabsorption.