Module 5: Liver

Question 1

Where does the catabolism of hemoglobin into globin, iron and biliverdin take place?

Answer 1

In the mononuclear phagocytes of the liver and spleen

Question 2

Source of bilirubin

Answer 2

Reduction product of bilirubin formed in mononuclear phagocytes

Question 3

How is most bilirubin transported in the plasma?

Answer 3

Unconjugated and loosely bound to albumin

Question 4

Most of the bilirubin in the bile is of what type?

Answer 4

Direct (conjugated)

Question 5

Where does the conjugation of bilirubin with glucuronic acid take place?

Answer 5

In hepatic cells

Question 6

Enzyme involved in the conjugation of bilirubin with glucuronic acid

Answer 6

UDP-glucuronyl transferase

Question 7

Where is urobilinogen produced

Answer 7

In the intestines by bacterial reduction of bilirubin

Question 8

What happens to urobilinogen in the intestine?

Answer 8

Some is excreted unchanged, some is oxidized and is excreted as stercobilin, some is re-absorbed into the blood and re-excreted in the urine and the bile

Question 9

Direct bilirubin is bilirubin conjugated with what?

Answer 9

Glucuronic acid

Question 10

Principle of the Evelyn-Malloy method for bilirubin

Answer 10

Conjugated (direct) bilirubin in soluble in acid solution and reacts directly with Diazo reagent; absorbance is measured at 1 minute; unconjugated (indirect) bilirubin requires the addition of methanol to make it soluble and reactive with bilirubin; total bilirubin is measured in the same tubes; indirect bilirubin=total bilirubin-direct bilirubin

Question 11

Reference interval for serum bilirubin in adults

Answer 11

Total = 0-17umol/L; direct = 0-3umol/L; indirect = 0-14umol/L

Question 12

What is delta bilirubin bound to?

Answer 12

1 albumin