Normal physiology

Topic Completed: 1 September 2012

Revised: 26 August 2019

Copyright: 2003-2019,, Inc.

PubMed Search: Gallbladder physiology[TIAB]

Hanni Gulwani, M.B.B.S.
Page views in 2018: 123
Page views in 2019 to date: 84
Cite this page: Gulwani H Normal physiology. website. Accessed September 16th, 2019.
Definition / general
  • Bile excretion is normally 500 - 1000 ml/day
  • Bile is concentrated 5 - 10x via active absorption of electrolytes accompanied by passive movement of water
  • Cholecystokinin causes gallbladder contraction and release of stored bile into gut
  • Bile is critical for intestinal absorption of dietary fat but the gallbladder is not
  • Bile is 2/3 bile salts, bicarbonate rich, has 3% organic solutes
  • 95% of secreted bile salts is reabsorbed in ileum and returned to liver via portal blood, called enterohepatic circulation of bile salts
  • Cholesterol is eliminated by loss of 0.5 g of bile salts per day
Bile constituents
Bile salts:
  • Cholates, chenodeoxycholates, deoxycholates, lithocholates, ursodeoxycholates
  • Major hepatic products of cholesterol metabolism
  • Family of water soluble sterols with carboxylated side chains
  • Are highly effective detergents, solubilize water insoluble lipids secreted by the liver (usually lecithin) into the biliary tree and promote dietary lipid absorption within the gut

Lecithin (phosphatidylcholine):
  • Hydrophobic, nonaqueous
  • Has minimal solubility in water
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