Quiz 8: Liver Function and Diseases Flashcards
Which of the following statements regarding the metabolism of bilirubin is true?
(a) It is a by-product of iron metabolism
(b) It is a metabolism product of the globin part of hemoglobin
(c) It is produced from the destruction of RBCs, protoporphyrin IX from hemoglobin is metabolized
(d) It is reduced to biliverdin prior to excretion
(c) It is produced from the destruction of RBCs, protoporphyrin IX from hemoglobin is metabolized
Bilirubin is transported from macrophages/reticuloendothelial cells to the liver by:
(a) Albumin
(b) Bilirubin-binding globulin
(c) Haptoglobin
(d) Transferrin
(a) Albumin
Which enzyme is responsible for the conjugation of bilirubin?
(a) Beta-Glucuronidase
(b) UDP-glucuronyl transferase
(c) Bilirubin oxidase
(d) Biliverdin reductase
(b) UDP-glucuronyl transferase
The delta bilirubin fraction refers to:
(a) Water-soluble bilirubin
(b) Free unconjugated bilirubin
(c) Bilirubin tightly bound to albumin by a covalent bond/not water soluble
(d) Conjugated/direct-reacting bilirubin
(c) Bilirubin tightly bound to albumin by a covalent bond/not water soluble
As a reduction product of bilirubin catabolism, this compound is partially reabsorbed from the intestines through the portal circulation for re-excretion by the liver. What is this compound?
(a) Azobilirubin
(b) Bilirubin
(c) Urobilin
(d) Urobilinogen
(d) Urobilinogen
Which of the following by itself would cause an increase in only the unconjugated bilirubin?
(a) Hemolytic anemia
(b) Obstructive jaundice
(c) Hepatitis
(d) Hepatic cirrhosis
(a) Hemolytic anemia
Which statement best characterizes serum bilirubin levels in a newborn, the first week following delivery?
(a) Serum bilirubin 24 hours after delivery should not exceed the upper reference limit for adults
(b) Jaundice is usually first seen 48 to 72 hours after delivery in neonatal hyperbilirubinemia
(c) Serum bilirubin above 5.0 mg/dL occurring 2 to 5 days after delivery indicates hemolytic or hepatic disease
(d) Conjugated bilirubin accounts for about 50% of the total bilirubin in neonates
(b) Jaundice is usually first seen 48 to 72 hours after delivery in neonatal hyperbilirubinemia
Which of the following is true about specimen collection and storage of bilirubin?
(a) A fasting sample is preferred as the presence of lipemia will increase measured bilirubin concentration
(b) A hemolyzed sample should be avoided as it may decrease the reaction of bilirubin with the diazo reagent
(c) Bilirubin is very sensitive to an is destroyed by light. Bilirubin values may be reduced by 30-50% per hour
(d) All of the above
(d) All of the above
In bilirubin determinations, the purpose of adding a concentrated caffeine solution or methyl alcohol is to:
(a) Allow unconjugated/indirect bilirubin to react with color reagent
(b) Dissolve conjugated bilirubin
(c) Precipitate protein
(d) Prevent any change in pH
(a) Allow unconjugated/indirect bilirubin to react with color reagent
Which statement about colormetric bilirubin methods is true?
(a) Direct bilirubin must react with diazo reagent under alkaline conditions
(b) Most methods are based upon reaction with diazotized sulfanilic acid and form an azobilirubin
(c) Ascorbic acid can be used to eliminate interference caused by Hgb
(d) The color of the azobilirubin product is independent of pH
(b) Most methods are based upon reaction with diazotized sulfanilic acid and form an azobilirubin
The following bilirubin results are obtained on a patient:
Day 1: 4.3 mg/dL (73.5 umol/L or mmol/L) Day 2: 4.6 mg/dL (78.7 umol/L) Day 3: 4.5 mg/dL (77.0 umol/L) Day 4: 2.2 mg/dL (37.6 umol/L) Day 5: 4.4 mg/dL (75.2 umol/L) Day 6: 4.5 mg/dL (77.0 umol/L)
Given that the controls were within acceptable confidence limits each day, and no hemolysis, what is the probable explanation for the result on day 4?
(a) No explanation necessary
(b) Serum, not plasma, was used for testing
(c) Specimen has a prolonged exposure to light
(d) Specimen was lipemic
(c) Specimen has a prolonged exposure to light
If the total bilirubin is 3.1 mg/dL (53.0 umol/L or 53.0 mmol/L) and the conjugated bilirubin is 2.0 mg/dL (34.2 umol/L), the unconjugated bilirubin is:
(a) 0.5 mg/dL (8.6 umol/L)
(b) 1.1 mg/dL (18.8 umol/L)
(c) 2.2 mg/dL (37.6 umol/L)
(d) 5.1 mg/dL (87.2 umol/L)
(b) 1.1 mg/dL (18.8 umol/L)
The principle of the tablet test for bilirubin in urine or feces is:
(a) The reaction between bile and 2,4-dicholornitrobenzene to a yellow color
(b) The liberation of oxygen by bile to oxidize orthotolidine to a blue-purple color
(c) Chemical coupling of bile with a diazonium salt to form a brown color
(d) Chemical coupling of bilirubin with a diazonium salt to form a blue to purple color
(d) Chemical coupling of bilirubin with a diazonium salt to form a blue to purple color
In the liver, bilirubin is converted to:
(a) Bilirubin-albumin complex/unconjugated bilirubin
(b) Bilirubin diglucuronide/conjugated bilirubin
(c) Urobilin
(d) Urobilinogen
(b) Bilirubin diglucuronide/conjugated bilirubin
In which of the following disease states is conjugated bilirubin a major serum component?
(a) Biliary obstruction
(b) Erythroblastosis
(c) Fetalis hemolysis
(d) Neonatal jaundice
(a) Biliary obstruction
