Deck 19: Liver

Question 1

A breakdown product of bilirubin metabolism that is produced in the colon from the oxidation of urobilinogen by microorganisms is:

A) Porphobilinogen.
B) Urobilin.
C) Stercobilinogen.
D) Protoporphyrin.
E) Protoheme.

Answer 1

Urobilin.

Question 2

The enzyme system that catalyzes the conjugation of bilirubin is known as:

A) Leucine aminopeptidase.
B) Glucose-6-phosphate dehydrogenase.
C) Uridine diphosphate (UDP) glucoronyl transferase.
D) Carbamyl phosphate synthetase.
E) Lactate dehydrogenase.

Answer 2

Uridine diphosphate (UDP) glucoronyl transferase.

Question 3

The cells that make up 70% of the liver's mass are:

A) Kupffer cells.
B) Hepatocytes.
C) Endothelial cells.
D) None of the above.

Answer 3

Hepatocytes.

Question 4

Which of the statements regarding bilirubin metabolism is TRUE?

A) It is a product of porphyrin metabolism.
B) It is reduced to biliverdin before excretion.
C) It is produced from the destruction of RBCs.
D) It is formed by the hydrolysis of the ?-methene bridge of urobilingen.

Question 5

Which is a characteristic of unconjugated bilirubin?

A) It is water-soluble.
B) It reacts faster than conjugated bilirubin.
C) It has the same absorbance properties as conjugated bilirubin.
D) It a not water-soluble.

Question 6

The term ?-bilirubin (delta) refers to:

A) Water-soluble bilirubin.
B) Free unconjugated bilirubin.
C) Bilirubin tightly bound to albumin.
D) Direct-reacting bilirubin.

Question 7

Kernicterus is the abnormal accumulation of bilirubin in:

A) Heart tissue.
B) Brain tissue.
C) Liver tissue.
D) Kidney tissue.
E) Blood.

Question 8

What is the most common cause of unconjugated hyperbilirubinemia?

A) Hemolytic anemia
B) Gilbert's disease
C) Bile duct obstruction
D) Dubin-Johnson
E) Neonatal physiologic jaundice

Question 9

Which of the following would be classified as prehepatic jaundice?

A) Hepatitis
B) Congestive heart failure
C) Rotor syndrome
D) Cancer of the bile ducts

Question 10

In obstructive liver disease, the following test results are found:

A) Feces: urobilinogen decreased; urine: bilirubin: positive; serum: conjugated bilirubin increased.
B) Feces: urobilinogen decreased or negative; urine: urobilinogen decreased or negative; serum: conjugated bilirubin decreased.
C) Feces: urobilinogen increased; urine: bilirubin: normal; serum: conjugated bilirubin normal or slightly elevated.
D) None of the above.

Question 11

The reagent (accelerator) in the Jendrassik-Grof bilirubin procedure that makes indirect bilirubin water-soluble is:

A) Hydrochloric acid.
B) Caffeine.
C) Methanol.
D) Alkaline tartrate.

Question 12

If a total bilirubin is 4.0 mg/dL and the conjugated bilirubin is 2.5 mg/dL, the unconjugated bilirubin is:

A) 1.0 mg/dL.
B) 1.5 mg/dL.
C) 2.0 mg/dL.
D) 3.0 mg/DldL.

Question 13

In the Jendrassik-Grof bilirubin, what converts purple azobilirubin to blue azobilirubin measured at 600nm?

A) Hydrochloric acid
B) Caffeine
C) Methanol
D) Alkaline tartrate

Question 14

Viral hepatitis that results in the largest percentage of chronic hepatitis is:

A) Hepatitis A.
B) Hepatitis B.
C) Hepatitis C.
D) Hepatitis D.

Question 15

The two most significant sources of error in accurate ammonia determinations are sample handling and:

A) Short shelf life of test reagents.
B) Inability to automate the test procedure.
C) Need for age-dependent reference ranges.
D) Ammonia contamination in the laboratory.

Question 16

The following disease is a recessive disorder of copper metabolism, which results in the accumulation of copper in the liver.

A) Hereditary hemochromatosis
B) Wilson's disease
C) ?₁-antitrypsin
D) Gilbert's disease

Question 17

An autosomal recessive disorder of iron metabolism, which is characterized by excessive iron absorption and accumulation in various tissues in the body, is termed:

A) Hereditary hemochromatosis.
B) Wilson's disease.
C) ?₁-antitrypsin.
D) Dubin-Johnson.

Question 18

A Model for End-Stage Liver disease staging system to predict prognosis in cirrhosis uses the following laboratory determinations EXCEPT:

A) Bilirubin.
B) INR.
C) Creatinine.
D) Aspartate transaminase.

Question 19

Nonalcoholic steatohepatitis is characterized by all of the following EXCEPT:

A) Necroinflammatory liver disease associated with accumulation of fat in the liver.
B) AST greater than ALT.
C) Consumption of less than 20g of ethanol daily.
D) No inflammation or scarring of the liver.