Content of Bile and Bile Release into Small Intestine

1. Content of Bile (made in Liver, released by Gall Bladder)
1. bile salts, bile pigments, cholesterol, neutral fats, phospholipids, electrolytes
2. bile salts - derivatives of cholesterol (cholic acid, chenodeoxycholic acid)
• emulsify fats - separate fats into tiny droplets for digestion & absorption
• enterohepatic circulation - conservation of bile salts by re-processing
• reabsorbed at in distal small intestine
• to liver via hepatic portal blood
• resecreted as bile from gall bladder
3. bile pigment (bilirubin) - waste product of heme from broken-down erythrocytes
• urobilinogen - breakdown product of bilirubin, causes darker coloration of feces
2. Regulation of Bile Release to Small Intestine
1. hepatocytes - cells of the liver that produce 0.5-1.0 liters of bile each day
2. parasympathetic - stimulates gall bladder release
3. cholecystokinin (CCK) - hormone released by cells of the mucosa of the duodenum
• acidic, fatty chyme enters duodenum -----> duodenal mucosa secretes CCK ----->
• gall bladder contracts to release bile
• pancreas secretes pancreatic juices
• hepatopancreatic sphincter opens
4. gallstones - crystallized formation of cholesterol and salts, causing obstruction of bile release

Category: Physiology Notes