Jaundice Flashcards
1
Q
Outline the breakdown of haemoglobin
A
- Haem
- Biliverdin
- Bilirubin
- Globin goes to the spleen where it is broken down into amino acids
2
Q
Why does bilirubin need to be conjugated?
A
- Unconjugated bilirubin is insoluble and needs to be bound to a carrier
- Liver conjugates bilirubin and make it soluble in water
- Conjugated bilirubin is recycled in enterohepatic circulation as bile
3
Q
What are the breakdown products of bile?
A
- Stercobilin (oxidised bilirubin)
- Enters duodenum and is excreted in faeces
- Gives faeces its brown colour
- Urobilinogen is excreted by kidneys in urine
4
Q
What does jaundice cause?
A
- Yellow skin/sclera
5
Q
What is pre-hepatic jaundice?
A
- Too much haem for liver to cope with
- Liver function is fine and there is no blockage
6
Q
What causes pre-hepatic jaundice?
A
- Increased haem
- Unconjugated bilirubin
- Due to haemoglobinopathies (sickle cell, thalassaemia, spherocytosis)
- Haemolysis
7
Q
What causes hepatic jaundice?
A
- Decreased hepatocyte function
- Conjugated and unconjugated bilirubin because some of the liver is still functional
- Caused by chronic liver disease and acute liver damage
8
Q
What causes post-hepatic jaundice?
A
- Obstruction to bile ducts within liver
- Blockage occurs before biliary tree
- Due to gallstones, biliary stricture, or pancreatic carcinoma at the head of the pancreas
9
Q
What other symptom occurs because of post-hepatic jaundice?
A
- Bilirubin has been conjugated so is water soluble
- Pathway for bilirubin to pass into duodenum has been blocked
- So all bilirubin diffuses into blood and is excreted by the kidneys
- Patient will have dark urine and pale stools
