12. Erythrocyte Physiology (Karius's lecture) Flashcards
Just going to hit the high points
How much oxygen can hemoglobin carry per gram?
1.34ml / gram
What organ senses our oxygen level to upregulate RBC synthesis?
The kidney
What does low O2 do to increase RBC levels?
It prevents the ubiquitination of HIF!
The relative upregulation of HIF leads to the production of which hormone?
Erythropoietin
What three things does Erythropoietin do?
Increases erythropoietic stem cells differentiating into proerythroblasts
Increases the maturation rate of committed RBC precursors
Decreases apoptosis of erythroid stem cells.
What is someone’s oxygen capacity?
What is someone’s oxygen content?
- 34 x grams of hemoglobin
- 34 x grams of hemoglobin x O2 Saturation %
What do red blood cells use ATP for? (4 things)
- Flexibility of membrane
- Ion-Transport
- Maintain iron in Fe++ state (Fe3+ doesn’t associate with O2 well, and doesn’t dissociate hardly at all)
- Prevent oxidation of Hb (prevent the O2 from randomly changing the conformation of the hemoglobin protien)
What organ produces Hepcidin?
What is blocked by Hepcidin, and how?
The liver (in response to an excess of iron)
Ferroportin gets internalized by the intestinal cells.
What is not produced in hereditary hemochromatosis?
Hepcidin
What is secondary polycythemia?
Increase in red blood cells over the normal due to altitude or lung / heart disease (actual low O2 levels)
What is Polycythemia Vera (Primary polycythemia)?
Is this disease associated with low or high EPO?
Increase in red blood cells due to bone marrow inducing hematopoiesis as a result of an abnormal signal (often not erythropoietin, in some cases may be thrombopoietin)
Erythropoietin is usually low.
Which direction does high CO2 push a hemoglobin dissociation curve?
To the right. (CO2 pushes the same direction as H+s)
What is methemoglobinemia?
Fe3+ in the hemoglobin
