Bilirubin Metabolism Flashcards
Lysis of erythrocytes occur in which organ
Spleen
Which molecule is converted to bilirubin in histiocytes
Heme
Which molecule helps to transport bilirubin through the blood
Albumin
What s bilirubin conjugated with to make it more soluble
Glucuronic acid
Conjugated bilirubin is secreted into what substance so it can go into the intestines
Bile
What is stercobilin
The converted form of urobilinogen that is excreted as a red brown color in feces
What is urobilin
The converted form of urobilinogen that gets excreted as a yellow color in urin
Which enzyme breaks down heme
Heme oxygenase
Heme oxygenase is responsible for the conversion of what
Heme to biliverdin
Biliverdin reductase is responsible for the conversion of what
Biliverdin to Bilirubin
UDP- glucuronyl transferase is responsible for the conversion of what
- Bilirubin to Bilirubin monoglucuronide
2. Bilirubin monoglucuronide to Bilirubin diglucuronide
What is the last product of bilirubin metabolism before it is converted to urobilirubin and excreted
Bilirubin diglucuronide
What is hyperbilirubinemia
Elevated plasma bilirubin levels
What are the three types of jaundice
Pre-hapatic, Hepatic and Post-hepatic
Which test can help differentiate between conjugated and unconjugated bilirubin
van den Bergh’s test
For unconjugated bilirubin, a direct van den Bergh’s test would show what
A purple color immediately
For unconjugated bilirubin, an indirect van den Bergh’s test would show what
no immediate color change after addition of alcohol
For unconjugated and conjugated bilirubin, an indirect and direct van den Bergh’s test would show what
Purple color that intensifies after addition of alcohol
What is kernicterus
Irreversible brain damage
Deficiency in UDP-gucuronyl transferase causes which disease
Criggler-Najar Syndrome (Type 1 more severe than type 2)
Which pathology associated with bilirubin metabolism is usually asymptomatic (only slight jaundice)
Gilbert’s Disease
Gilbert’s disease occurs as a result of
Defective uptake of bilirubin by liver
What is the pathology behind hemolytic crisis
More bilirubin in the blood than albumin can transport
What is the pathology behind hemolytic (Rh) disease of newborns
The mom is Rh -ve, while the baby is Rh +ve. Can lead to the fetus having kernictus
Apart from hemolytic disease of the newborn, what are two other hemlytic crises
Sickle cell crisis and G6PDH deficiency
What is physiological jaundice common in most newborns
There is destruction of RBCs and the enzyme foe metabolism have not fully developed yet
What is the pathology behind alcoholic jaundice
Increased breakdown of hemoglobin, so liver is unable to break it all down, which causes an increase in unconjugated bilirubin
What is the pathology behind obstructive jaundice
Increase in conjugated bilirubin due to occlusion of bile duct
Three causes of obstructive jaundice
Gall stones, pancreatic head cancer, bile duct cancer
What generally causes pre-hepatic jaundice
Increased hemolysis
What generally causes hepatic jaundice
Liver damage which results in decreased bilirubin excretion
What generally causes post-hepatic jaundice
Bile duct obstruction which leads to bilirubin excretion
