04c: Biliary Tree, Autoimmune Flashcards
Bile composed mainly of (water/lipid). The major components are:
Water
- Bile acids
- Phospholipids (lecithins)
- Cholesterol
- Bile pigments (BR)
T/F: Cholesterol accounts for over 50% of the organic components of bile.
False - present only in small amounts (4%)
T/F: Bile acids account for over 50% of the organic components of bile.
True
Cholic and chenodeoxycholic acid are examples of (X), synthesized from (Y).
X = Primary bile acids Y = cholesterol
Deoxycholic and lithocholic acid are examples of (X), synthesized from (Y).
X = Secondary bile acids Y = primary bile acids
Bile acids are made more (hydrophobic/hydrophilic) by (X) process in the liver, which converts them to (Y).
Hydrophilic
X = conjugation (with taurine or glycine)
Y = bile salts
What’s the purpose of bile acid conjugation in the liver?
Permits their accumulation within intestine to facilitate fat digestion/absorption
Bile salts are more (hydrophilic/hydrophobic) than bile acids, with (higher/lower) pKa and (increased/decreased) resistance to pancreatic enzyme hydrolysis.
Hydrophilic;
Lower (remain ionized in intestine at physiological pH);
Increased
T/F: Bile acids returning to liver is negative feedback for additional secretion of bile.
False - potent stimulus of additional bile secretion
T/F: Bile acids returning to liver is negative feedback for additional synthesis of bile acids.
True
(Liver/gallbladder) concentrates bile by actively (reabsorbing/secreting) (X).
Gallbladder
Reabsorbing
X = Na, Cl, HCO3
(Water follows)
Major stimulus for gallbladder contraction and (X) sphincter relaxation.
X = sphincter of Oddi
CCK
(Active/passive) bile acid reabsorption occurs specifically at (X) whereas (active/passive) reabsorption occurs throughout (small/large) intestine.
Active (Na-bile ATPase/cotransporter);
X = terminal ileum
Passive;
Small (and some in large) intestine
Two basic types of gallstones: (star the more common type in Western societies)
- Cholesterol* (75%)
2. Pigment
Basic underlying problem in cholesterol gallstone formation is:
Failure of bile constituents to maintain cholesterol in solution
RFs for cholesterol gallstone formation.
- MAINLY: 4F’s (forty, fat, F, fertile)
- Increasing age
- Rapid weight loss
- Ileal disease
- Genetics
- Certain drugs
FHx of cholesterol gallstone formation indicates potential mutation in gene encoding (X), leading to extremely (high/low) (Y).
X = hepatocanalicular phosphatidylcholine transporter (ABCB4)
Low;
Y = biliary phosphatidylcholine
List some drugs that increase risk of cholesterol gallstone formation.
- Fibrates
- Estrogen
- Oral contraceptives
Pigment gallstones are (black/brown).
Both can occur (two different subtypes)
Major component in pigment gallstones:
Ca bilirubinate
Pathogenesis of pigment gallstones is believed to involve (conjugation/deconjugation) and (X) of (Y).
Deconjugation;
X = precipitation
Y = BR
RFs associated with black pigment gallstones.
- Chronic hemolysis (SCD, thalassemia)
- Cirrhosis
- CF
- Long-term total parenteral nutrition
RFs associated with brown pigment gallstones.
- Biliary stasis/infection
- Choledochal cysts
- Periampullary diverticulum
T/F: Most (2/3) of patients with gallstones are asymptomatic.
True
Biliary colic is (relieved/provoked) by food intake. How might the patient describe nature/location of pain?
Provoked;
Episodic and severe with sudden onset, steep rise, and steady plateau that lasts for hours; usually located in epigastrium or RUQ (radiates to upper back)
T/F: Biliary colic is thought to be the result of hypoxia.
False - tonic spasm around a transiently obstructed cystic duct