Disorders of Gallbladder and Biliary Tract

Question 1

where is bile formed?

Answer 1

hepatocytes/canaliculus

Question 2

describe the course of bile after formation

Answer 2

1. formed in hepatocytes/bile ducts
2. modified in ductules and ducts
3. concentrated, stored, in gallbladder
4. delivery of bile to duodenum is regulated by Sphincter of Oddi

Question 3

describe the zones of the liver

Answer 3

zone I: portal area, effected first by toxic inj, viral hepatitis

zone II: in-between

zone III: central vein area; affected first by ischemia, alc hep.

Question 4

what are sinusoids?

Answer 4

irregular capillaries w/ fenestrated endothelium, no BM –> macromlecules have full access to basal surface of hepatocytes through Disse

Question 5

how does secretion into bile canaliculus work?

Answer 5

an active process “bile salt pump”

Question 6

what is bile made of?

Answer 6

bile acids, phospholipids, chol*, bilirubin, ions/water

*bile is the only relevant mechanism for cholesterol excretion

Question 7

how is bilirubin formed, how does it get to the hepatocyte?

Answer 7

breakdown of erythrocytes –> bilirubin. bilirubin bound by albumin in blood, delivered to hepatocytes –> conjugated by glucoronyl transferase –> conjugated bili –> secreted into bile canaliculus

Question 8

main function of the gallbladder

Answer 8

concentrates bile

Question 9

Contractile function of the gallbladder is impt b/c….

Answer 9

decreased emptying is a major risk factor for gallstone formation

Question 10

2 functions of bile

Answer 10

1. fat digestion and absorption (of fat soluble vitamins)
2. elimination of waste products (chol)

Question 11

what controls bile secretion?

Answer 11

mainly CCK: released from duodenum in response to fat, AA, peptides –>

• Gb contraction
• sphincter relaxation
• release of pancreatic enzymes
• inhibition of gastric emptying

also secretin

Question 12

micelles

Answer 12

in bile acid

emulsify lipids –> soluble

important for digestion, transport, absorption of lipid soluble substances (like ADEK)

Question 13

enterohepatic circulation of bile acids

Answer 13

bile acids are almost all recycled (little excreted)

99% taken up in terminal ileum

Question 14

what happens w/ loss of ileal function?

Answer 14

no longer retaining sufficient bile acids –>risk of….

• steatorrhea
• diarrhea
• nephrolithiasis
• cholelithiasis

Question 15

cholelithiasis sx

Answer 15

• epigastric/RUQ pain
• crescendo-plateau-decrescendo
• nausea/vomiting
• preceding pain attacks

Question 16

causes of jaundice

Answer 16

increased unconj bili

• overproduction of bilirubin (ex. hemolysis)
• defective uptake
• defective conjugation

increased conj bili

• defective excretion (intra/extra-hepatic)

Question 17

name and describe 3 hereditary hyperbilirubinemias

Answer 17

Gilbert’s: decreased GT

Crigler-Najar:

• type I: no GT
• type II: very low GT

Dubin-Johnson and Rotor syndrome: probelm w/ excretion of bili

Question 18

causes of cholestasis

Answer 18

intrahepatic or extrahepatic

Question 19

cholestasis sx

Answer 19

jaundice, gray stool, dark urine

pruritis

Question 20

cholestasis labs

Answer 20

increased bili, ALP, GGT

increased chol, xanthomas

malabsorption of fat and fat soluble vitamins

Question 21

causes of extrahepatic cholestasis

Answer 21

high direct/conj bili

• gallstones
• strictures
• neoplasia
• parasites

Question 22

risk factors for gallstones

Answer 22

• increasing age
• female gender (cholesterol stones): pregnancy, estrogens
• genetics, fam hx
• lifestyle: obesity, abstinence of ETOH, low physical activity, diet, rapid weight loss
• disease: DM, Crohn’s

Question 23

what % of the pop has gallstones?

Answer 23

10% of adults

mostly asymptomatic

Question 24

gallstones and pregnancy

Answer 24

pathophys: increased Gb volume, decreased Gb contractility

Sx: absent Murphy’s sign, AP normally elevated in pregnancy

management: safest time for cholecystectomy is 2nd trimester

Question 25

acute cholecystitis

Answer 25

acute inflammation of gallbladder wall, usually caused by obstruction from gallstone

Question 26

sx, exam, labs, imaging of acute cholecystitis

Answer 26

ongoing RUQ/epigastric pain Murphy's sign Labs: elevated bili, AST, ALT Imaging: US

Question 27

pathological finding in chronic cholecystitis

Answer 27

Rokitansky-Aschoff sinus

Question 28

acute acalculous cholecystitis

Answer 28

in pts w/ severe and acute systemic illnesses due to ischemia, gb stasis, biliary sludge, secondary bacterial contamination

Question 29

gangrenous (necrotizing) cholecystitis

Answer 29

rare, 10% mortality, perforation common coagulative necrosis of gb wall

Question 30

what is the most sensitive diagnostic procedure for gallstones and dilated bile ducts?

Answer 30

abdominal US

Question 31

why would you do an ERCP for gallstones?

Answer 31

only do it for tx b/c risk of pancreatitis (5%)

Question 32

choledocholithiasis sx, exam

Answer 32

sx: recurrent RUQ/epigastric pain, may resolve, preceding episodes exam nonspecific

Question 33

labs in choledocholithiasis

Answer 33

classic cholestatic picture: increased Bili, ALP, GGT, AST, ALT may be transient

Question 34

complications of choledocholithiasis

Answer 34

cholangitis, pancreatitis, cirrhosis

Question 35

pathogenesis of cholangitis

Answer 35

obstruction --\> stasis --\> bacterial overgrowth --\> infection

Question 36

cholangitis clinical picture

Answer 36

Charcot's triad: RUQ pain, jaundice, fever Reynold's pentad: Charcot + MS changes + shock on exam: very ill appearing, jaundice, tenderness labs: elevated bili, ALP, GGT, AST, ALT imaging: US - dilated CBD

Question 37

possible complications of gallstones

Answer 37

* cholecystitis: acute/chronic, empyema, perforation * choledocholtihiasis: obstructive jaundice, ascending cholangitis * pancreatitis * more rare: biliary enteric fistula, gallstone ileus, porcelain gallbladder

Question 38

gallbladder carcinoma

Answer 38

very rare late dx, poor prognosis risk factors: gallstones, other chole probs

Question 39

sclerosing cholangitis

Answer 39

primary: chronic, fibrosing, inflammatory process of bile ducts --\> obliteration of biliary tree and cirrhosis secondary: chronic biliary obstruction w/ secondary fibrosis --\> biliary cirrhosis

Question 40

sclerosing cholangitis is associated with....

Answer 40

UC (and more rarely, Crohn's)

Question 41

cholangiocarcinoma

Answer 41

tumor of cholangiocytes rare but increasing incidence (10-15% hepatic malignancies) poor survival

Question 42

Klatskin tumor

Answer 42

cholangiocarcinoma of bifurcation