Bile Production

The liver is central to a multitude of physiologic functions, including bile production, sugar storage in the form of glycogen, nutrient inter-conversion among proteins, lipids and carbohydrates, detoxification and drug metabolism, phagocytosis, synthesis of many blood proteins, usually in combination with other systems and organs.

Hepatocytes excrete bile into bile canaliculi that join the bile duct in the portal triad, and finally coalesce to form the right and left bile ducts. They join outside the liver to form the common hepatic duct. The common hepatic duct unites with the cystic duct which drains the gallbladder to form the common bile duct. The latter one enters the duodenum at the duodenal papilla along with the pancreatic duct. Bile has several functions, mainly involved in fat absorption. When food enters the mouth, the sphincter around the duodenal papilla relaxes and when gastric contents enter the duodenum, the hormone from the small intestine causes the gallbladder to contract [119].

The liver produces and secretes about 600-1000 ml of bile per day, which circulates three times. Gallbladder, a small pouch that sits just under the liver, can store about 40-70 ml of bile that is five to ten times more concentrated than that of freshly secreted bile. There are no digestion enzymes in bile; the main components are bile salts, which neutralize and dilute stomach acid and emulsify fat. Cholesterol and alkaline phosphatase are excreted in the bile, many of which are subsequently reabsorbed into the enterohepatic circulation.

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