Morphogenesis of the Liver and Biliary System

Question 1

Why the right hepatic lobe has lower oxygenation and greater hematopoietic activity than the left hepatic lobe………..?

Answer 1

Because of the fetal oxygen saturation is lower in portal than in umbilical venous blood

The portal venous inflow is directed mainly to the right lobe of the liver and umbilical flow primarily to the left.

Question 2

Fetal liver metabolism is devoted primarily to the production of……..

Answer 2

Proteins required for growth

Many fetal hepatic functions are carried out by the maternal liver, which provides nutrients and serves as a route of elimination of metabolic end products and toxins

Question 3

Albumin concentrations are low in a neonate…….

Answer 3

(~2.5 g/dL), reaching adult levels (~3.5 g/dL) after several mo

Question 4

Drug toxicity are the responses to chloramphenicol

Answer 4

Gray baby syndrome

Question 5

Newborn infants have decreased activity of hepatic uridine diphosphate glucuronosyltransferase, which converts

Answer 5

Unconjugated bilirubin to the readily excreted glucuronide conjugate and

This is the rate-limiting enzyme in the excretion of bilirubin

Question 6

Microsomal activity can be stimulated by administration of …….

Answer 6

Phenobarbital, rifampin, or other inducers of cytochrome P450.

Question 7

2 primary bile acids…..

Answer 7

Cholic acid and chenodeoxycholic acid, are synthesized in the liver

Question 8

In an adult, this enterohepatic circulation involves…….% of the circulating bile acid pool

Answer 8

90–95

Question 9

Causes of Impaired Bile Acid Metabolism and Enterohepatic Circulation

Answer 9

DEFECTIVE BILE ACID SYNTHESIS OR TRANSPORT

ABNORMALITIES OF BILE ACID DELIVERY TO THE BOWEL

LOSS OF ENTEROHEPATIC CIRCULATION OF BILE ACIDS

BILE ACID MALABSORPTION

DEFECTIVE UPTAKE OR ALTERED INTRACELLULAR METABOLISM

Question 10

DEFECTIVE BILE ACID SYNTHESIS OR TRANSPORT

Answer 10

• Inborn errors of bile acid synthesis (reductase deficiency, isomerase deficiency)
• Progressive familial intrahepatic cholestasis (PFIC1, PFIC2, PFIC3)
• Intrahepatic cholestasis (neonatal hepatitis)
• Acquired defects in bile acid synthesis secondary to severe liver disease

Question 11

ABNORMALITIES OF BILE ACID DELIVERY TO THE BOWEL •

Answer 11

• Celiac disease (sluggish gallbladder contraction)

* Extrahepatic bile duct obstruction (e.g., biliary atresia, gallstones)

Question 12

LOSS OF ENTEROHEPATIC CIRCULATION OF BILE ACIDS •

Answer 12

• External bile fistula
• Cystic fibrosis
• Small bowel bacterial overgrowth syndrome (with bile acid precipitation, increased jejunal absorption, and “short-circuiting”)
• Drug-induced entrapment of bile acids in intestinal lumen (e.g., cholestyramine)

Question 13

BILE ACID MALABSORPTION

Answer 13

• Primary bile acid malabsorption (absent or inefficient ileal active transport)
• Secondary bile acid malabsorption
• Ileal disease or resection
• Cystic fibrosis

Question 14

DEFECTIVE UPTAKE OR ALTERED INTRACELLULAR METABOLISM

Answer 14

• Parenchymal disease (acute hepatitis, cirrhosis)
• Regurgitation from cells
• Portosystemic shunting
• Cholestasis