Erythrocyte Physiology Flashcards
What is Erythropoiesis?
The process of producing red blood cells.
If Oxygen is low, the kidney will accumulate_______?
HIF (hypoxia inducible factor)
What kind of hormone does the kidney produce if O2 is low?
Erythropoietin. Acts on Stem cells
What are the actions of Erythropoietin ?
Acts on stem cells: increase differentiation into proerythroblats.
Increases maturation rate of committed erythrocytic precursors.
Increases more release of RBCs from bone marrow.
Which form of Iron is favored in the stomach?
Ferric form (Fe3+)
Which form of Iron is favored in the Heme?
Ferrous state (Fe2+)
How much oxygen does each gram of Hemoglobin carry?
1.34 mL O2/g of Hb.
What is Hemochromatosis?
What causes it?
Iron overload
Caused by genetic mutation: inadequate production of Hepcidin.
What is Polycythemia?
What are the effects?
Too many RBCs
More Oxygen carrying capacity: blood become thicker, heart has to work harder to pump blood(increased viscosity).
What is Polycythemia Vera(Primary Polycythemia)
Bone marrow is making RBC when there is no need to
Oxygen Content=?
Oxygen capacity x % saturation
Why is ATP needed by RBCs?(5 things)
Anaerobic glycolysis Flexibility of membrane ion transport maintain Iron in Ferrous state rather than in Ferric state Prevent oxidation of Heme
What is Hemochromatosis?
“Iron overload” caused by a missense mutation in the gene for Hepcidin. Reduced hepcidin leads to increase Feroportin and increase Iron levels.
What is Secondary Polycythemia?
Bone marrow normal; responds to low oxygen levels.
Oxygen may be low because of high altitude; lung/heart disease.
What is Methemoglobinemia?
The presence of large amounts of Iron in the Fe3+ state in the heme.
