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Gall bladder disease. Harrison 2012 Baghbanian M. MD . Bile Secretion and Composition. Hepatic bile : isotonic fluid with an electrolyte composition resembling blood plasma. Gallbladder : water reabsorption → concentration of bile increases. components of bile . - PowerPoint PPT Presentation

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Gall bladder diseaseHarrison 2012Baghbanian M. MD Bile Secretion and CompositionHepatic bile : isotonic fluid with an electrolyte composition resembling blood plasma.

Gallbladder: water reabsorption concentration of bile increasescomponents of bile bile acids (80%), lecithin and phospholipids (16%)cholesterol (4.0%).

In the lithogenic state, the cholesterol value can be as high as 810%.

components of bile conjugated bilirubin proteins (all immunoglobulins, albumin, metabolites of hormones)ElectrolytesMucusdrugs and their metabolites.

daily basal secretion 500600 mL. Many substances taken up or synthesized by the hepatocyte are secreted into the bileprimary bile acidscholic acid chenodeoxycholic acid

are synthesized from cholesterol in the liver,

conjugated with glycine or taurine

secreted into the bile.Secondary bile acidsdeoxycholate lithocholateursodeoxycholic acid (UDCA).

formed in colon as bacterial metabolites of the primary bile acids. Bile acids are detergent-like molecules Cholesterol solubility in bile depends on: lipid concentration percentages of bile acids and lecithin.

Normal ratios of these formation of solubilizing mixed micellesabnormal ratios cholesterol crystalsBile acids major physiologic force for hepatic bile flow

aid in water and electrolyte transport in the small bowel and colon.Enterohepatic Circulation

normal bile acid pool: 24 g. During digestion of a meal, one or more enterohepatic cyclesNormally: 510 times daily. 95% efficient; fecal loss of bile acids is in the range of 0.20.4 g/d.

Enterohepatic Circulation

fecal loss =daily synthesis of bile acids

bile acid pool is maintained.

the maximum rate of synthesis is 5 g/dGallbladder and Sphincteric Functions

capacity of gallbladder is 30 mL

In the fasting state, the sphincter of Oddi resistance to bile flowprevent reflux of duodenal contents into the pancreatic and bile ducts filling of the gallbladder.

cholecystokinin(CCK) major factor for : GB evacuationreleased from : duodenal mucosa In response to: fats and amino acids.

CCK produces (1) powerful contraction of the gallbladder, (2) decreased resistance of the sphincter of Oddi,(3) enhanced flow of bile into duodenum.

Phrygian cap partial or complete septum (or fold) separates the fundus from the body. Anomalies of position or suspension are not uncommon : left-sidedintrahepatic retrodisplacement

"floating" gallbladderpredisposes to acute torsion, volvulus, or herniation

GallstonesEpidemiology and Pathogenesis

prevalent in most western countries.

USA : 7.9% in men and 16.6% in women.

high in Mexican Americans low in African Americans

gallstonestwo major types:

cholesterol stones : > 80%

pigment stone < 20%.

gallstonesCholesterol gallstones : >50% cholesterol + calcium salts, bile pigments, and proteins.

Pigment stones : calcium bilirubinate;