RBC Physiology Flashcards
Function of RBC
Carry O2 from lungs to tissue and trasport CO2 from tissue to lungs and buffer H+
Uniquie RBC properties
-Flexibility
-Strength
-Shape-> increased surface area
-Hemoglobin
-Lifespan-> short
Deformability of RBC
-Structure of membrane and cytoskeleton
-High surface area to volume ratio
-Low viscosity cytoplasm
RBC life span
Relatively short
-Horses have the longest with cats and dogs on the lower end
Time for Erythropoiesis
5-7 days
What stimulates erythropoiesis
Erythropoietin, produced from the kidney, stimulates stem cells in the bone marrow (spleen is minor) to erythroid precursors and continues to stimulate them to induce maturation.
What triggers erythropoietin release
Hypoxia in the tissues (renal hypoxia specifically)
-Anemia
-Poor renal perfusion
-Poor oxygenation of blood (altitude)
High EPO
Erythroid hyperplasia
-Shortened maturation time
-Accelerated release of reticulocytes
-increased Hgb synthesis in dividing cells
-Decreased apoptosis of progenitor cells
Persistently low EPO
Erythroid hypoplasia
-Gradual onset of anemia
Could be from decreased functional renal tissue or inflammation
Iron on erythropoiesis
A deficiency in iron results in anemia due to impaired RBC production
Irons role in RBC
At center of heme molecule is Fe2+ which is what reversibly binds oxygen and this Hgb concentration is the rate limiting step in erythropoiesis
MetHgb
Oxidized form (Fe3+) and lacks the electron pairs for O2 to bind
CO and Hgb
Has a higher affinity to bind to Hgb than O2 and will displace
Ferritin
Rapidly mobilized iron pool (KSU is the only lab that can measure this)
Hemosiderin
Stable form of stored iron, aggregate of denatured ferritin and less readily available