Flashcards in Bilirubin Pathways Deck (46):
bilirubin is an open chain called?
a tetrapyrrole rings
bilirubin breakdown of blood usually where?
Macrophages break form RBCs, then what?
into haem>biliverdin>free bilirubin
colour of bilirubin?
colour of biliverdin?
some double bonds in bilirubin isomerize when what? what does that do to bilirubin?
exposed to light = more soluble
When use phototherapy for bilirubin?
2 forms of bilirubin?
conjugated and unconjugated
bilirubin usually excreted as?
conjugated (glucuronide) in bile
high bilirubin in newborns?
RBCs stimulated by?
how many RBCs made a die per second?
future RBCs leave the bone marrow as what? how long to mature to RBCs?
reticulocytes mature in a day
how long to create RBCs from stems?
what is met-haemoglobin?
Fe3+ that doesn't bind O2 well
What is in white pulp and red pulp in spleen?
White pulp: T/B cells
Red pulp: blood vessels to remove old RBCs via macrophages
Mononuclear phagocyte is precursor to?
Are there Mononuclear phagocytes in the liver?
yes. the Kupffer cells help out
what does the white pulp in spleen do?
opsonizes old RBCs to help with recognition by macrophages
aged RBCs lose what on their surface?
neuraminic/sialic acid from glycophorin
3 big factors for haemolysis?
What is Haptoglobin?
plasma protein that binds haemoglobin of RBCs that die away from spleen, allows macrophages to remove
Haptoglobin looks like?
what carried haem (not Haemoglobin) to liver?
hemopexin recycles the iron
4 consequences of haemolysis
unconjugated bilirubin = jaundice
Fe2+ carried by?
Haem oxygenase produces?
How is biliverdin produces from Haem?
via haem oxygenase
Bruises: what happens at?
1-2 days: blue, purple black: deoxy/met-Hb
5-10 days: green/yellow = biliverdin
10-14 days: yellow/brown = bilirubin
>14 days : fades away
serum albumin binds what?
HIGHLY hydrophobic bilirubin
what converts bilirubin to conjugated bilirubin?
bilirubin UDP glucuronyltransferase
whats the difference between conjugated and unconjugated bilirubin?
conjugated is soluble
defect in bilirubin UDP glucuronyltransferase leads to what disease?
what actively pumps bilirubin diglucuronide into canaliculi?
cMOAT or MRP2
what is Crigler-Najjar disease?
defect in bilirubin UDP glucuronyltransferase
What is Dubin Johnson syndrome? prognosis?
defect in cMOAT
asymptomatic, no Rx necessary
Crigler-Najjar disease symptoms?
What is kernicterus?
bilirubin in brain
Crigler-Najjar disease initial and subsequent treatment?
initially: phototherapy 10-12 hr/day
subsequently: liver transplant
How much bile is recycled?
95% in terminal ileum
what are bile pigments?
what are bile salts?what do they do?
detergent derivatives of cholesterol
90% of urobilinogen in faeces, 10% goes where?
10% back into portal vein
9% back to biliary system
1% into kidney and into urine = yellow pee
Why does old pee look more yellow?
+++ oxidized urobilinogen