Blood Metabolism Flashcards
How many iron molecules are there in one RBC?
4 (one per each heme group
What is the production site for heme? (organ and cell location)
85% de l’hème est produite par les cellules érythroïdes de la moelle osseuse
15% est produite par les hépatocytes où l’hème est utilisée pour la synthèse des
cytochromes et autres enzymes
La première et les 3 dernières réactions ont lieu dans la mitochondrie et les 4 autres dans le cytosol
True or False, virtually all cells in the body can produce heme.
False
toutes les cellules peuvent produire de l’hème** SAUF les globules rouges** qui n’ont
plus de mitochondries
What are conditions cliniques appelées « porphyries »?
associées à une déficience partielle dans l’une des enzymes de synthèse de l’hème->
déficience en synthèse de l’hème -> une diminution de la synthèse de l’hémoglobine avec anémie
What is the “dracula” or loup garoup disease?
porphyrie: due to the behaviour associated with the decreased blood production
Why can hemoglobin transport oxygen?
La possibilité de transporter de l’O2 lui est conféré par la présence des 4 atomes de fer de son hème. Chaque atome de fer peut se lier de façon** réversible à une molécule d’oxygène**
Where does the blood get the color from?
Iron is what gives blood the red color
When bound to oxygen: rouge vif
When not bound to oxygen: dark red
The vein blood looks blue due to light absorption from the skin
What is the half life of RBCs? What is a clinical relation to this>
90-120 days
No point to ask for a RBC blood test every week more like every 3 months
Describe the breakdown of hemogloblin.
Mention, heme, iron, globline, albumin and issues
hemogloblin is broken into
heme and globlin(proteins)
globlin can be broken down by proteases
the iron from the heme is bound to tranferrine which will transport iron to the right tissue
the heme without the iron becomes protoporphyrine IX -> biliverdine -> bilirubin (non conjugated)
issue: bilirubin is not water soluble, need a transport protein : albumin
What is the role of albumin in relation to blood?
It is bound to non-conjugated bilirubin and transports it to the liver
What is the role of the liver in relation to blood?
Bilirubin bound to albumin goes to the liver
The liver conjugates the bilirubin making it more soluble
Where does conjugated bilirubin go to and what does it become?
Goes to the vesicule biliaire
Upon food ingestion, bile is secreted into the intestins
here, bilirubin becomes ’urobilinogène and then majority becomes stercobiline qui confère aux selles leur couleur brune caractéristique
a small part of urobilinogène est réabsorbée vers le sang et retourne vers le
foie. this is transfered via blood to the kidneys which transforms it into urobiline (jaune) et l’excrétera dans l’urine.
True or False,
The yellow color of urine is due to stercobiline
FALSE
Due to urobiline
stercobiline gives brown color to feces
- What would you excpect to see in a patient with a block in the urinary pathway?
- What other problem can cause a similar reaction?
- Block in urinary pathway = difficulty in secreting bilirubin (specifically urobilin)
Condition called hyperbilirubinemia (high bilirubin blood levels) .
Which means, the urine color will not be yellow (red ish) and that the build up of bilirubin can be seen and yellow eye color.
- destruction importante des GRs ou d’une insuffisance du foie
You have a patient presenting with hyperbilirubinemia. You get the lab results back and want to decide what the issue is. What should you look at?
Test must include conjugated levels of bilirubin and un-conjugated
if your bilirubin is conjugated (in the blood test), then the issue is unlikely the liver. However, if most of the bilirubin is non-conjugated, the issue is likely to be the liver.
