Gastro 16 - Biliary Tract

Question 1

Where is bile made?

Answer 1

In the liver by hepatocytes.

Question 2

Describe the flow of bile from the liver to the duodenum.

Answer 2

Bile flows from the left and right hepatic ducts into the common hepatic duct. Then it flows into the cystic duct into the gallbladder, where it is stored. When the gallbladder contracts, bile flows back into the cystic duct to the common bile duct (where the cystic duct and common hepatic duct come together). Then it joins the main pancreatic duct into the ampulla of Vater.

Question 3

What is the main hormone that causes contraction of gallbladder?

Answer 3

Cholecystokinin. Chole- means bile. Cyst- means bag. Kinin- moving.

Question 4

What does cholecystokinin do?

Answer 4

Makes the gallbladder contract. Delays gastric emptying. Stimulates pancreatic enzyme secretion.

Question 5

What is a bile salt?

Answer 5

Bile salts (cation {e.g. Na+} plus a bile acid (oxidized cholesterol like cholic acid, deoxycholic acid, chenodeoxycholic acid). Most bile acids are conjugated w/ glycine (making glycocholic acid) or taurine (making glycocholic acid).

Question 6

What is the use of bile?

Answer 6

To emulsify lipid particles so it can be digested. Excreting cholesterol and bilirubin. Copper excretion. Bactericidal for the food we ingest.

Question 7

What is the composition of bile?

Answer 7

Bile salts. Bilirubin (conjugated because unconjugated is not soluble in water). Cholesterol. Phospholipids. Electrolytes.

Question 8

Where does bilirubin comes from?

Answer 8

From the breakdown of hemoglobin in unconjugated state, where it binds to albumin to be transported to the liver. There, it is conjugated and excreted into the bile.

Question 9

What does the colon do to the bilirubin excreted in the duodenum?

Answer 9

The colonic bacteria convert it to urobilinogen which is oxidized to stercobilin (making the stool brown) and excreted in the stool. A small amount of urobilinogen is reabsorbed by the gut; this is called enterohepatic circulation. A tiny amount of the reabsorbed uribilinogen is converted to urobilin and excreted in the urine, and is what makes urine yellow.

Question 10

What would be the three causes of increased unconjugated hyperbilirubinemias?

Answer 10

Increased bilirubin production. Impaired bilirubin uptake and storage. Decreased UDP-GT activity.

Question 11

What would be three causes of increased bilirubin production?

Answer 11

Hemolytic anemia. Sickle cell disease. Hematoma breakdown.

Question 12

What would be the two causes of impaired bilirubin uptake and storage?

Answer 12

Viral hepatitis. Drugs.

Question 13

What would be the three causes of decreased UDP-GT activity?

Answer 13

Gilbert syndrome. Crigler-Najjar syndrome Type I and II. Neonatal physiologic jaundice.

Question 14

What would be the four causes of conjugated hyperbilirubinemias?

Answer 14

Impaired transport. Biliary epithelial damage. Intrahepatic biliary obstruction. Extrahepatic biliary obstruction.

Question 15

What would be two causes of impaired transport of conjugated hyperbilirubinemias?

Answer 15

Dubin-Johnson syndrome. Rotor syndrome.

Question 16

What would be the causes of biliary epithelial damage that would lead to conjugated hyperbilirubinemia?

Answer 16

Hepatitis. Cirrhosis. Liver failure.

Question 17

What would be three causes of biliary obstruction leading to conjugated hyperbilirubinemia?

Answer 17

Primary biliary cirrhosis. Sclerosing cholangitis. Drugs (chlorpromazine, arsenic).

Question 18

What would be the four causes of extrahepatic biliary obstruction leading to conjugated hyperbilirubinemia?

Answer 18

Pancreatic neoplasms. Pancreatitis. Cholangiocarcinoma. Choledocholithiasis.

Question 19

How can we clinically distinguish b/w intrahepatic biliary obstruction vs extrahepatic biliary obstruction in a patient that shows up in the ER with jaundice?

Answer 19

Do a RUQ ultrasound; it will tell you if there is an extrahepatic biliary obstruction.

Question 20

What is Primary Sclerosing Cholangitis (PSC)?

Answer 20

Disease causing concentric fibrosis of bile ducts; scarring and strictures. “Beads on a string” on ERCP. Mostly men around age 40. Up to 80% have positive pANCA. Associated w/: ulcerative colitis, cholangiocarcinoma.

Question 21

What is Primary Biliary Cirrhosis (PBC)?

Answer 21

Autoimmune disease, causing T lymphocytes attacking bile ductules within the liver parenchyma. Can cause granulomas and leads ultimately to cirrhosis. 90% are middle-aged women. Positive Anti mitochondrial Ab (AMA). Associated w/ other autoimmune disorders : CREST scleroderma, Sjogren syndrome, Rheumatoid arthritis.

Question 22

What one particular drug is useful for the treatment of primary biliary cirrhosis And what does it do?

Answer 22

Ursodiol (ursodeoxycholic acid). It is a bile acid that decreases synthesis of cholesterol in the liver, changes the composition of bile and delays progression of PBC. It will not reverse the damage already done, but improves survival by slowing down further damage.

Question 23

What is the definitive treatment for both Primary biliary cirrhosis and Primary Sclerosing Cholangitis?

Answer 23

Liver transplant.

Question 24

What is Secondary Biliary Cirrhosis?

Answer 24

Cirrhosis from biliary obstruction secondary to some extrahepatic process blocking biliary outflow.

Question 25

What are the symptoms of Primary biliary cirrhosis, Primary Sclerosing Cholangitis, and secondary biliary cirrhosis?

Answer 25

Jaundice. Pruritus. Dark urine. Light-colored (acholic) stools. Increased in alkaline phosphatase. Increased in direct bilirubin.

Question 26

What is the difference b/w cholelithiasis, cholecystitis, cholangitis, and choledocholithiasis?

Answer 26

Cholelithiasis: gallstones. Cholecystitis: inflammation/infection of the gall bladder. Cholangitis: inflammation/infection of the biliary tree. Choledocholithiasis: gallstones in the bile ducts.

Question 27

What are the risk factors of cholelithiasis?

Answer 27

[4 Fs] Fat, Fertile (pregnancy, oral estrogens), Females, over Forty (never see gall stones before the age of 40).

Question 28

What are the three types of stones that cause cholelithiasis?

Answer 28

Cholesterol stones. Pigment stones. Mixed stones.

Question 29

What is Biliary colic?

Answer 29

RUQ pain due to Gall bladder contraction w/ eating.

Question 30

What is Pneumobilia?

Answer 30

Fistula b/w the gall bladder and the intestine causing air in the biliary tree.

Question 31

What is the name of a gallstone obstructing the ileocecal valve?

Answer 31

Gallstone ileus.

Question 32

What is the hallmark triad of cholangitis?

Answer 32

Called Charcot’s triad: Jaundice. Fever. RUQ abdominal pain.

Question 33

What is Reynold’s pentad?

Answer 33

Charcot’s traid (Jaundice, fever, RUQ abdominal pain) + hypotension and altered mental status. Also seen in cholangitis.

Question 34

What is Cholecystitis and what are the causes?

Answer 34

Infection and inflammation of the gall bladder. Causes positive Murphy sign. Usually due to gallstones. Rarely due to ischemia or viral infection (CMV).

Question 35

What does Clonorchis sinensis do?

Answer 35

“Liver fluke”, causes inflammation of the biliary tree. Related to pigmented gallstones and cholangiocarcinoma.

Question 36

What is the difference b/w Primary Biliary cirrhosis and Primary sclerosing Cholangitis?

Answer 36

PBC: Positive AMA, Middle-aged women, Autoimmune. PSC: Positive pANCA, Men over 40, Associated w/ UC and cholangiocarcinoma, “Beads on a string” on ERCP.