UW Cholesterol gallstones

Question 1

3 types of gallstones?

Answer 1

Cholesterol

Pigment:

a) brown (aka mixed)
b) black

Question 2

Cholesterol stones are formed when the ability of bile salts to solubilize cholesterol is overwhelmed by …..

Answer 2

high concentrations of cholesterol in bile.

Question 3

Cholesterol stones appearance?

Answer 3

yellow to pale gray and hard

Question 4

black pigment gallstones are composed of …

Answer 4

calcium salts of unconjugated bilirubin (calcium bilirubinate)

Question 5

pigment gallstones appearance?

Answer 5

soft, and are dark brown to black.

Question 6

Brown pigment stones typically arise secondary to .2

Answer 6

bacterial (eg, Escherichia coli) or helminthic (eg, Ascaris lumbricoides, Clonorchis sinensis) infection of the biliary tract.

Question 7

why infections of billiary tracts leads to formation of brown gallstones?

Answer 7

infection of the biliary tract results in the release of beta-glucuronidase by injured hepatocytes and bacteria (microbial enzyme).

Question 8

function of beta-glucuronidase?

Answer 8

This enzyme hydrolyzes bilirubin glucuronides and increases the amount of unconjugated bilirubin.

Question 9

what blirubin increases in the presence of beta-glucoronidase?

Answer 9

unconjugated

Question 10

liver fluke C sinensis is common in what countries?

Answer 10

East Asian countries

Question 11

apart from infection in what cases pigment gallstones may also occur?

Answer 11

when excess bilirubin is excreted, such as with chronic hemolytic anemia.

Question 12

endogenous beta-glucuronidase in the biliary tract does what?

Answer 12

A small amount of conjugated bilirubin normally becomes deconjugated

Question 13

When large amounts of conjugated bilirubin are excreted into the bile, enough becomes deconjugated to promote black pigment stone formation.

Answer 13

.

Question 14

what conditions leads to black stones?

Answer 14

chronic hemolysis (sickle cells, spherocytosis)
Increased enterohepatic cycling of bilirubin (eg ileal disease)

Question 15

What tissue attaches gallbladder to liver?

Answer 15

The cystic plate is a fibroareolar tissue that attaches the superior surface of the gallbladder to the liver.

Question 16

in which squares of liver lies gallblader?

Answer 16

lies on the cystic plate (gallbladder bed) under the liver segments IVB and V.

Question 17

Most common gallstones?

Answer 17

cholesterol

Question 18

Cholesterol presentation on xray?

Answer 18

Radiolucent with radiopaque areas due to calcifications.

Question 19

Cholesterol stones composition?

Answer 19

Cholesterol monohydrate crystals and calcium carbonate

Question 20

Black stones presentation on xray?

Answer 20

Radiopaque

Question 21

Brown stones presentation on xray?

Answer 21

Radiolucent

Question 22

Black stones composition?

Answer 22

calcium bilirubinate

Question 23

Hemolysis –> what stones?

Answer 23

black

Question 24

infection –> what stones?

Answer 24

brown

Question 25

what solubilizes cholesterol in bile? 2

Answer 25

Bile salts and phosphatidylcholine

Question 26

what conditions (incr and decr) predispose for cholest. stones formation since cholesterol cannot be dissolved?

Answer 26

incr. cholesterol concentration; decr. bile salts; decr. phosphatidylcholine.

Question 27

Risk factors for gallstone formation?

Answer 27

``` Obesity rapid weight loss female sex glucose intolerance hypomotility of the gallbladder (eg, pregnancy, prolonged fasting). ```

Question 28

Obesity. Stones?

Answer 28

Cholesterol

Question 29

Rapid weight loss. stones?

Answer 29

Cholesterol

Question 30

female sex. stones?

Answer 30

Cholesterol

Question 31

glucose intolerance. Stones?

Answer 31

Cholesterol

Question 32

hypomotility of the gallbladder (eg, pregnancy, prolonged fasting). stones?

Answer 32

Cholesterol

Question 33

pregnancy, stones?

Answer 33

Cholesterol

Question 34

prolonged fasting, stones?

Answer 34

Cholesterol

Question 35

total parenteral nutrition (TPN) leads to what enteral physiologic changes? 2

Answer 35

decreased CCK release and subsequent biliary stasis.

Question 36

enteral passage of what substances leads to trigger to CCK?

Answer 36

enteral passage of fat and amino acids into the duodenum

Question 37

in what part of intestines fat and amino acids stimulate CCK?

Answer 37

duodenum

Question 38

extensive resection of the ileum can have disruption to .....

Answer 38

the normal enterohepatic circulation of bile acids

Question 39

extensive resection of the ileum --> disruption to the normal enterohepatic circulation of bile acids --> what result on gallbladder?

Answer 39

leading to inadequate solubilization of biliary cholesterol and formation of cholesterol crystals.

Question 40

cirrhosis. stones?

Answer 40

black

Question 41

Why advanced liver disease can impair cholesterol conversion to bile acids?

Answer 41

due to the diminished synthetic ability of injured hepatocytes, leading to supersaturation of the bile with cholesterol

Question 42

cirrhosis increase risk of cholesterol gallstones. what symptoms seek?

Answer 42

hepatocellular dysfunction!!!

Question 43

how changes cholesterol levels in total parenteral nutrition (TPN)?

Answer 43

Serum triglyceride levels may rise on TPN, but TPN does not contain significant amounts of cholesterol, and serum cholesterol levels do not usually change significantly. cholesterol stones - due to lack of enteral stimulation and decr. release of CCK.

Question 44

gastrin effect on gallstones?

Answer 44

none

Question 45

what catalyzes the rate-limiting step in the synthesis of bile acids?

Answer 45

Cholesterol 7α-hydroxylase

Question 46

Cholesterol 7α-hydroxylase catalyzes what?

Answer 46

Rate-limiting step in the synthesis of bile acids

Question 47

what medications increase cholesterol content in bile, which increases the risk of gallstones?

Answer 47

Fibrate (fenofibrate, gemfibrozil)

Question 48

what does fibrate?

Answer 48

upregulate lipoprotein lipase, resulting in increased oxidation of fatty acids

Question 49

fibrate effect on cholesterol stone formation and why?

Answer 49

fibrates inhibit cholesterol 7α-hydroxylase, which catalyzes the rate-limiting step in the synthesis of bile acids

Question 50

fibrate effect on bile acid?

Answer 50

decreased productio

Question 51

Estrogens increase the biosynthesis of cholesterol by upregulating ....

Answer 51

upregulating hepatic HMG-CoA reductase activity

Question 52

estrogen medication effect on cholesterol gallstones?

Answer 52

increase the amount of cholesterol secreted in bile and contribute to formation of gallstones

Question 53

Aromatase function?

Answer 53

Aromatase catalyzes the conversion of androgens to estrogen

Question 54

Inhibition of aromatase leads to ....

Answer 54

lead to reduced gallstone formation (aromatase catalyzes conversion of androgens to estrogens)

Question 55

β-glucuronidase does what on bilirubin?

Answer 55

deconjugates bilirubin, and the resulting free bilirubin precipitates with calcium in the bile to form pigmented gallstones

Question 56

Decreased activity of β-glucuronidase on gallstones formation?

Answer 56

Decreased activity of this enzyme would reduce the formation of pigmented stones but would not affect the formation of cholesterol gallstones.

Question 57

HMG-CoA reductase does what in cholesterol synthesis?

Answer 57

catalyzes the conversion of HMG-CoA to mevalonate, the rate-limiting step in cholesterol synthesis

Question 58

decr HMG-CoA reductase activity on cholest stones?

Answer 58

Decreased activity would reduce cholesterol synthesis and the amount of cholesterol secreted in bile, discouraging cholesterol stone formation

Question 59

what medications for cholest stones?

Answer 59

hydrophilic bile acids (eg, ursodeoxycholic acid)

Question 60

effect of hydrophilic bile acids (eg, ursodeoxycholic acid)?

Answer 60

reduces cholesterol secretion and increases biliary bile acid concentration. This improves cholesterol solubility and promotes gallstone dissolution

Question 61

Bile acid sequestrants (eg cholestyramine) net result on gallstones?

Answer 61

The net result is no significant change in the risk of gallstones.

Question 62

Bile acid sequestrants (eg cholestyramine) effect on enterohepatic recirculation of bile acids?

Answer 62

Decrease enterohepatic recirculation of bile acids (increase gallstone risk).

Question 63

Bile acid sequestrants (eg cholestyramine) effect on conversion of cholesterol to bile acids and motility?

Answer 63

stimulate the conversion of cholesterol to bile acids and increase biliary motility (decrease gallstone risk).

Question 64

Progesterone on bile acids?

Answer 64

progesterone reduces bile acid secretion

Question 65

Estrogen on cholesterol?

Answer 65

Estrogen increases cholesterol secretion

Question 66

Progesterone on bile emptying?

Answer 66

Progesterone slows gallbladder emptying

Question 67

what gallbladder actively absorbs?

Answer 67

water from bile

Question 68

conditions that cause gallbladder hypomotility result in .....

Answer 68

excessive dehydration of bile --> bile becomes concentrated -->viscous biliary sludge.

Question 69

viscous biliary sludge results from what?

Answer 69

hypomotility result in excessive dehydration of bile --> bile becomes concentrated

Question 70

Biliary sludge symptoms?

Answer 70

asymptomatic biliary colic (RUQ abdominal pain associated with nausea) also precursor to stone formation (particularly cholesterol stones). Complications such as acute cholecystitis and cholangitis can also occur in patients with biliary sludge.