Week 3: Hematopoiesis
• Erythrocyte
• Leukocyte
• Platelet
• Plasma and serum
• Stem cell theory
• Hemoglobin
• Hematocrit
• Anticoagulant
• EDTA
Blood
• Circulate O2, nutrients, heat, etc.
• Erythrocyte
• Leukocyte
• Platelet (thrombocyte)
• Plasma and serum
Inside of a blood vesselSEM x 2,500
Anticoagulant
• Chelate Ca++ ions• EDTA• Citrate
• Inhibit clotting enzyme• Heparin
• Inhibit glycolysis• Fluoride
Erythrocytes, leukocytes and thrombocytes SEM x1,825
Stem Cell Theory
• Pleuripotential stem cell
• Blast cells
• Differentiation and maturation
• Release into circulation
Recycling Old Cells
• RBCs have 120-day life span
• Reticulo-endothelial system removes old and damaged cells
• Hemoglobin is made of Fe++, porphyrin ring, and globin chains
• Fe++ and globin chains (amino acids) are recycled, but porphyrin ring is eliminated
Red Cell Production
• Oxygen tension
• Level of erythropoietin EPO
• Need for more red cells (during growth, recovering from anemia)
Hemoglobin
• Normal adult Hb A• 2 globin chains
• 2 globin chains
• Heme: porphyrin plus Fe++
• Minor Hb’s• 22: Hb A2
• 22: Hb F
Kinds of Hemoglobin
• Oxyhemoglobin: O2
• Reduced (deoxy-) hemoglobin: no O2
• Methemoglobin: oxidized
• Carboxyhemoglobin: 218 times affinity to CO than O2
• Sulfhemoglobin: sulfa drugs
Hb Problems
• Heme production problem: porphyria
• Fe++ problems: IDA, hemochromatosis
• Globin problem: sickle cell disease, thalassemia
Hb Test
• Reference ranges:• Male 14.0 - 17.0 g%
• Female 12.0 - 15.0 g%
• Cyanomethemoglobin method• Drabkin’s reagent - ferricyanide
• Coulter Hemoglobinometer
Hematocrit
• Reference ranges• Male 42 - 52%• Female36 - 46%
• Packed cell volume
• Modern instruments calculate Hct from RBC and average cell size
Correlation
• Internal QC
Hb x 3 ≈ Hct ± 3
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