Lec 15 Flashcards
What makes up majority of bile?
mostly water, then bile salts
What is effect of bile on biliary flow?
more bile acids in biliary tree = better flow
What are the 2 primary bile acids?
cholic acid, chenodeoxycholic acid
How are primary bile acids synthesized?
synthesized in liver from cholesterol
rate limiting enzyme = 7 alpha hydroxylase
What are the secondary bile acids?
deoxycholic acids and lithocholic acid
How are secondary bile acids formred?
- conjugation of primary bile acid with AA glycine or taurine
- secreted in bile
- oxidized by intestinal bacteria
What happens to bile salts in intestine?
70-80% reabsorbed in distal ileum and return to liver via portal vein
10-15% reabsorbed in colon after bacterial deconjucation
10-15% lost in feces
What percent of bile salts in circulation are recirculated vs new?
> 95% recirculated
< 5% are from new synthesis
What mediates gallbladder contraction?
CCK
What are some of bile duct disease?
things get backed up; have cholestasis = bile standing still
- -> excess bile acids –> hepatocyte injury
- -> excess bilirubin –> jaundice
- -> excess cholesterol –> xanthomata
What is the effect of ileal disease or ingestion of bile acid-binding resins [cholestyramine]
have insufficient reabsorption of bile acids
What is the effect of bile acid depletion?
steatorrhea, gallstones
What is the effet of bile acid free-flow into colon?
diarrhea
What happens if you get bile acid accumulation in skin?
itching –> pruritis
What are gallstones composed of?
bilirubin [pigmented]
cholesterol
both
When do you get pigmented gallstones?
when high concentrations of unconjugated bilirubin in bile
due to hemolysis, liver disease, infected bile, starvation of total parenteral nutrition
What are pigmented gallstones made of?
bilirubin and calcium = not crystals
What is relationship acidity of gallbladder and likelihood of stone precipitation?
more acidic –> less likely to get stones
When do you get cholesterol gallstones?
40, female, fat, fertile
Where do cholesterol vs pigmented stones localize?
cholesterol stone = in gallbladder not ducts
pigmented = can arise in either gallbladder of bile ducts
What is biliary colic?
stone stuck in cystic duct causes pain
Are you more likely to get gallstone in fed or fasting state?
fasting
What is acute cholecystitis?
cystic duct obstruction + infection
80% subside w/ antibiotics alone
What can you give to dissolve cholesterol gallstones?
ursodeoxycholic acid = main constituent of bear bile; liquefies the bile
side effect = diarrhea
What is biliary sludge?
history looks like biliary colic but may not have an actual stone yet
