Liver Function and Porphyrin Formation

Question 1

Bilirubin

Answer 1

Product of breakdown of Hgb, forms complex with albumin (unconjugated) for transport to liver, conjugated in liver, excreted into bile

Question 2

Urobilinogen

Answer 2

Conjugated bilirubin reduces by anaerobic bacteria in intestine

Some reabsorbed to get excreted in urine

Question 3

Urobilin

Answer 3

Urobilinogen oxidized by anaerobic bacteria

Gives stool color

Question 4

Jaundice

Answer 4

Yellow discoloration from increased bilirubin concentration (> 2-3 mg/dL), deposited in skin and sclera of eyes

Question 5

Kernicterus

Answer 5

Elevated bilirubin deposits in brain of infants

Question 6

Prehepatic jaundice

Answer 6

Excessive RBC destruction (hemolytic anemia,spherocytosis, toxic conditions)

Increased unconjugated bilirubin in serum

Question 7

Gilbert syndrome

Answer 7

Transport problem of bilirubin from sinusoids membrane to microsomal region

Mild increase in unconjugated bilirubin

Question 8

Crigler-Najjar disease

Answer 8

Deficiency of UDP-glycuronyltransferase

Little conjugated bilirubin formed, increased serum unconjugated bilirubin

Question 9

Dubin-Johnson syndrome

Answer 9

Impaired transport of conjugated bilirubin in hepatocyte from microsomal region to bile canaliculi

Increased conjugated bilirubin, slight increase in unconjugated bilirubin

Question 10

Neonatal physiological jaundice

Answer 10

Low levels of UDP-glycuronyltransferase at birth

Increased serum unconjugated bilirubin

Question 11

Intrahepatic cholestasis

Answer 11

Caused by hepatic injury like cirrhosis, bile duct injury, or neoplasms

Question 12

Posthepatic jaundice

Answer 12

When obstruction blocks flow of bile into intestines (extrahepatic cholestasis) cause by gallstones, neoplasms, inflammatory conditions

Significantly increased serum conjugated bilirubin, increased serum unconjugated bilirubin, increased urine conjugated bilirubin
Decreased urine/decal urobilinogen (pale stool)

Question 13

Bilirubin ref ranges

Answer 13

Infant total bilirubin = 2-6 mg/dL
Adult total bilirubin = 0.2-1.0 mg/dL
Adult unconjugated = 0.2-0.8 mg/dL
Adult conjugated = 0-0.2 mg/dL

Question 14

ALP - slight increase
AST - marked increase
ALT - marked increase
GGT - slight increase

Answer 14

Acute hepatitis

Question 15

ALP - marked increase
AST - slight increase
ALT - slight increase
GGT - marked increase

Answer 15

Obstructive jaundice

Question 16

ALP - slight increase
AST - slight increase
ALT - slight increase
GGT - slight increase

Answer 16

Chronic hepatitis