Erythropoiesis: RBC Production Flashcards
Where are RBCs produced?
In the bone marrow
What is the RBC stages of development?
Stem cell –> Rubriblast –> Prorubricyte –> Rubricyte –> Metarubricyte –> Polychromatophil –> Mature RBC
How long does the maturation process take?
3-4 days
What is RBC production stimulated by??
Decreased arterial partial pressure of oxygen (PO2), which leads to tissue hypoxia in the kidneys.
What hormone stimulates RBC production and what organ releases it?
Erythropoietin, released by the kidney
What happens if there are increased levels of erythropoietin?
Hemoglobin synthesis starts earlier and cell divisions may be skipped, resulting in larger (immature) RBCs (shift red cells)
What happens if RBC production is decreased, or more destruction occurs?
Anemia
What can slow down RBC production?
Increases in renal oxygen tension
What is the approximate RBC circulating lifespan in cats and dogs?
~100 days in dogs
~85-90 days in cats
Approximately when is the entire blood supply of RBCs replaced?
About every 30 days
What are the primary functions of RBCs?
- Accumulate oxygen from lungs
- Transport and release oxygen
- Replace released oxygen with waste gas
- Transport CO2 to lungs
What is blood plasma composed of?
90% water
10% dissolved substances
What are RBCs composed of?
65% water
5% organelles, enzymes, salt
30% hemoglobin
What are common RBC morphology features?
- Rouleaux, stacking
- Anisocytosis, size variation
- Poikilocytosis, shape variation
What are the 5 categories of RBC morphology changes?
- Regenerative changes
- Immune-mediated damage
- Oxidative injury
- Membrane/metabolic disorder
- Mechanical fragmentation
What does the Regenerative Change sub-group contain?
Cells which have appeared due to anemia, generally includes immature cells:
1. Polychromatic RBC
2. Reticulocytes
3. Shift RBC
4. nRBC
5. Howell-Jolly body
6. Basophilic stippling
7. Anisocytosis
What does the Immune-Mediated Damage sub-group contain?
Contains RBCs that are being targeted by the immune system:
1. Ghost cell
2. Spherocyte
3. Agglutination
What does the Oxidative Injury sub-group contain?
Occurs when hemoglobin is oxidized and denatured due to disease or drugs:
1. Erythrocyte Refractile Bodies (ER Bodies)
2. Heinz body
3. Eccentrocyte
What does the Metabolic/Membrane Disorder sub-group contain?
Due to environmental disorder:
1. Echinocytes
2. Crenated cell
3. Burr cell
4. Acanthocyte
5. Blister cell
6. Keratocyte
7. Sickle cell
8. Hypochromasia
9. Elliptocyte (Ovalocyte)
10. Leptocyte
- Leptocyte: Torocyte
- Leptocyte: Stomatocyte
- Leptocyte: Target Cell (Codocyte)
- Leptocyte: Bar cell (Knizocyte)
What does the Mechanical Fragmentation sub-group contain?
Results from mechanical damage:
1. Schistocytes (Schizocytes)
2. Dacryocyte
What are the 3 most common RBC parasites in dogs?
- The Hemotropic mycoplasma; Mycoplasma hemocanis
- Babesia canis
- Babesia gibsoni
What are the 3 most common RBC parasites in cats?
- The Hemotropic mycoplasma; Mycoplasma hemofelis
- Candidatus mycoplasma sp.
- Cytauxzoon felis
3 RBC tests?
- Coomb’s Test
- Erythrocyte Sedimentation Rate
- Autoagglutination
What does the Coomb’s Test test for?
For Immune-mediated hemolytic anemia
What does the Autoagglutination test for?
Immune-mediated hemolytic anemia
