UW Cholesterol gallstones Flashcards
3 types of gallstones?
Cholesterol
Pigment:
a) brown (aka mixed)
b) black
Cholesterol stones are formed when the ability of bile salts to solubilize cholesterol is overwhelmed by …..
high concentrations of cholesterol in bile.
Cholesterol stones appearance?
yellow to pale gray and hard
black pigment gallstones are composed of …
calcium salts of unconjugated bilirubin (calcium bilirubinate)
pigment gallstones appearance?
soft, and are dark brown to black.
Brown pigment stones typically arise secondary to .2
bacterial (eg, Escherichia coli) or helminthic (eg, Ascaris lumbricoides, Clonorchis sinensis) infection of the biliary tract.
why infections of billiary tracts leads to formation of brown gallstones?
infection of the biliary tract results in the release of beta-glucuronidase by injured hepatocytes and bacteria (microbial enzyme).
function of beta-glucuronidase?
This enzyme hydrolyzes bilirubin glucuronides and increases the amount of unconjugated bilirubin.
what blirubin increases in the presence of beta-glucoronidase?
unconjugated
liver fluke C sinensis is common in what countries?
East Asian countries
apart from infection in what cases pigment gallstones may also occur?
when excess bilirubin is excreted, such as with chronic hemolytic anemia.
endogenous beta-glucuronidase in the biliary tract does what?
A small amount of conjugated bilirubin normally becomes deconjugated
When large amounts of conjugated bilirubin are excreted into the bile, enough becomes deconjugated to promote black pigment stone formation.
.
what conditions leads to black stones?
chronic hemolysis (sickle cells, spherocytosis) Increased enterohepatic cycling of bilirubin (eg ileal disease)
What tissue attaches gallbladder to liver?
The cystic plate is a fibroareolar tissue that attaches the superior surface of the gallbladder to the liver.
in which squares of liver lies gallblader?
lies on the cystic plate (gallbladder bed) under the liver segments IVB and V.
Most common gallstones?
cholesterol
Cholesterol presentation on xray?
Radiolucent with radiopaque areas due to calcifications.
Cholesterol stones composition?
Cholesterol monohydrate crystals and calcium carbonate
Black stones presentation on xray?
Radiopaque
Brown stones presentation on xray?
Radiolucent
Black stones composition?
calcium bilirubinate
Hemolysis –> what stones?
black
infection –> what stones?
brown
what solubilizes cholesterol in bile? 2
Bile salts and phosphatidylcholine
what conditions (incr and decr) predispose for cholest. stones formation since cholesterol cannot be dissolved?
incr. cholesterol concentration;
decr. bile salts;
decr. phosphatidylcholine.
Risk factors for gallstone formation?
Obesity rapid weight loss female sex glucose intolerance hypomotility of the gallbladder (eg, pregnancy, prolonged fasting).
Obesity. Stones?
Cholesterol