Bilirubin and the biliary tree Flashcards
What is bilirubin?
It is formed from RBC degradation in the spleen forming heme.
This is then converted to biliverdin
This is then converted to bilirubin by biliverdin reductase
How is unconjugated bilirubin carried to the liver?
Via albumin
What is bilirubin conjugated with?
Glucaronic acid
What is stercobilin?
Bilirubin that makes poo brown
What is urobilin?
Bilirubin that makes urine straw colour
Why does jaundice occur?
Build up of bilirubin the blood
What is a pre hepatic cause of jaundice and what would you see biochemically?
Anything that increases heamolysis, eg SCA
It would cause increased levels of unconjugated bilirubin
What is a hepatic cause of jaundice and what would you see biochemically?
Anything that blocks the liver. Cirrhosis, fatty liver
Increased un or conjugated depending where it is
What is a post hepatic cause of jaundice and what would you see biochemically?
A blocking of the biliary tree
Increased conjugated
You may get pale stools and dark urine if none get so these systems
Draw a biliary tree
What test can reveal acute pancreatitis?
Amylase
What tumour marker could suggest hepatic cancer?
AFP
What scan is best when wanting to see gall stones?
US
What scan is best when wanting to see pancreatitis?
CT
What scan can show liver function?
HIDA
When is an MRCP used?
To see inflammation
What is an ERCP used for?
What can it cause?
- is used to gain biopsies and enters up the biliary tree.
- It can also be used to put dye in
Acute pancreatitis
How big should the cystic duct be?
6mm 1mm for every 10 years after 60
What is the difference between the ampulla of vater and sphincter of oddi?
A of V - union of CBD and major pancreatic duct
S of O - Sphincter controlling release to duodenum
What makes urobilinogen?
Gut Bacteria
What turns Haem to biliverdin?
Haem reductase
