Flashcards in GB and Biliary Tree Diseases (Nichols/Tomb) Deck (61)
Function of bile acids in bile?
solubilization of cholesterol
Modulation of Intestinal motility
Function of phospholipid in bile?
Solubilization of cholesterol
Protection of bile duct epithelium
Function of IgA and IgM in bile?
Function of mucus in bile?
prevention of bacterial adhesion
Function of glutathione in bile?
induction of bile flow
Most frequent type of gallstones?
Pured and mixed cholesterol stones
What are pure and mixed cholesterol stones comprised of?
- Monohydrate cholesterol crystals
- Matrix of mucin glycoprotein
- Ca salts of unconjugated bilirubin
What are brown pigmented stones comprised of?
cytoeskeleton of bacteria
Brown pigmented stones most commonly occur in patients with:
Black pigmented stones most commonly occur in patients with:
liver disease, hemolysis, older age
What are black pigmented stones comprised of?
--Pure Ca bilirubinate
How does age cause cholesterol hypersecretion?
age-related decr in 7-alpha-hydroxylase
How does estrogen cause cholesterol hypersecretion?
Increased cholesterol uptake (Increased lipoprotein receptors B and E)
How does obesity cause cholesterol hypersecretion?
Incr cholesterol synthesis
(increase HMG coA activity)
How does progesterone cause cholesterol hypersecretion?
Increased free cholesterol
(Inhibitor of AcoA CAT, Decreased conversion of cholesterol to cholesteryl ester stores)
Bile acid Synthesis: The rate-limiting enzyme is :
How does marked weight reduction cause cholesterol hypersecretion?
Mobilization of tissue cholesterol
How does ileal disease/resection/bypass cause cholesterol hypersecretion?
Impaired bile acid absorption or excessive losses
What is "supersaturated" bile?
Bile that has a CSI greater than 1, which means the amt of cholesterol exceeds the max holding capacity of micelle
What are vesicles?
very large carriers of cholesterol, which do NOT contain bile salts
Multilamelar vesicles permit:
What is crystal formation?
Aggregation process by which a crystal particle is formed from supersaturated bile
How are crystals generated?
vesicular fusion and aggregation
What changes in bile composition enhance crystal formation?
high cholesterol saturation and an increased deoxycholate content
5 Factors which inhibit crystal formation:
1. low total lipid conc
2. decr cholesterol saturation
3. biliary proteins not binding Con-A
4. Apolipoprotein A-I and A-II
How does gallbladder emptying relate to gallstone formation?
delay in gallbladder emptying
4 GB-related abn that are risk factors for gallstones:
1. Defective acidification of gallbladder bile
2. > pH higher ppt of Ca salts
3. GB stasis can cause incr mucin, which interferes w/ mechanical emptying
4. Decr response to CCK
Cholesterol gallstone pathogenesis:
Hepatic chol hypersecretion causes:
1. GB hypomotility
2. mucin hypersecretion
3. chol gallstone formation
Incr intestinal conversion to deoxycholate,
1. directly causes GS formation
2. hepatic chol hypersecretion
Risk factors for black pigment stone formation:
Long term TPN