Jaundice Flashcards
What is Jaundice?
due to excessive accumulation of bilirubin in tissues
What are the three metabolism of bilirubin?
- Production of unconjugated bilirubin
- Conjugation of bilirubin
- Excretion of bilirubin
Where are rbc broken down and why?
in the spleen by macrophages
How is unconjugated bilirubin made?
- rbc broken down by macrophage in spleen
2. degrade into hb into iron and unconjugated bilirubin
Where is the iron stored and the unconjugated bilirubin taken?
- Iron stored inside trasnferrin proteins
2. Unconjugated bilirubin travels to liver and binds to albumin
Is unconjugated bilirubin insoluble?
yes
In disease where can unconjugated bilirubin be produce?
by haemolysis of rbc outside of spleen
How is bilirubin conjugated?
- Liver hepatocytes uptake unconjugated bilirubin
2. Gets conjugated to glucuronate
Is conjugated bilirubin soluble?
yes
Once bilirubin is conjugated where is it secreted into?
bile canaliculi
Where does the bilirubin flow?
with the bile down bile ducts into duodenum
How is conjugated bilirubin metabolized?
by bacteria into colourless products
Why is feaces brown?
- reabsorbed by the gut and excreted by kidney but most oxidized in gut into coloured pigement which give faeces brown colour
- If complete obstruction of bile ducts, no flow of CB, no conversion so no urobilinogen in urine
What is prehepatic jaundice?
caused by excess production of bilirubin
What is hepatic jaundice?
due to pathology of liver (hepatocytes and bile canliculi) (e.g. Hepatitis and PCS)
What is post-hepatic jaundice?
problem with biliary flow
What is obstructive jaundice?
cause by lack of bile flow into gut
How does obstructive jaundice manifest?
pale faeces + dark urine
What is cholestatic jaundice?
caused by bilirubin not flowing out via CBD