Hema- Erythrocyte

• Normoblastic


  One of the RBC maturation series
• RBC Maturation Series


  1. Normoblastic

  2. Rubriblastic

  3. Erythroblastic
• Pronormoblast


  • Begins to accumulate the components necessary for hemoglobin production
  • N:C ratio of 8:1
  • 1 or 2 Nuclei
  • Dark blue - RNA and ribosomes concentration
  • May show small tufts of irregular cytoplasm along the membrane periphery
• Basophilic Normoblast


  • Condensation of Chromatin= revealing clumps (nuclear membrane periphery)
  • N:C ratio decreases to 6:1
  • Appear deeper, richer blue than in the Pronormoblast, hence basophilic
• Polychromatic (Polychromatophilic) Normoblast


  • N:C ratio decreases from 4:1 to 1:1
  • Pink color - hemoglobin accumulation over time and concurrent decreasing amounts of RNA, resulting in a mixture of pink and blue
  • Murky gray-blue color
• Orthochromic Normoblast


  • Pyknotic nucleus
  • N:C ratio is approximately 1:2
  • Increase in salmon pink color
• Polychromatic (Polychromatophilic) Erythrocyte or Reticulocyte


  • Bluish tinge - residual ribosomes and RNA
  • A small amount of residual ribosomal RNA is present, however, and can be visualized with a vital stain such as new methylene blue
• Erythrocyte


  • 7 to 8 um in diameter (Rodak's 6th Ed)/6 to 8 um in diameter (Brown's 6th Ed. Hematology)
  • Wright -stained blood film- salmon -pink stained cell with a central pale area that corresponds to the concavity 1/3 the diameter- central pallor
• Pronormoblast


  Begins to accumulate the components necessary for hemoglobin production
• Basophilic Normoblast


  Start of hemoglobin synthesis
• Polychromatic (Polychromatophilic) Normoblast


  Last stage capable of mitosis
• Erythrokinetics is the term describing the dynamics of RBC production and destruction
• Hypoxia


  The stimulus to red blood cell production
• Erythrocyte Destruction


  Mature erythrocyte, a nonnucleated cell: unable to generate new proteins (enzymes), cellular functions decline, the cell ultimately approaches death<|>Lacks mitochondria, therefore relies on glycolysis for ATP production<|>RBC lifespan: 90- 120 days
• Erythropoietin


  Produced by peritubular fibroblasts in the kidneys in response to hypoxia<|>Has 3 major effects: early release of reticulocytes from the bone marrow, prevents apoptosis, and decreases transit time of RBC to mature
• Nomenclatures used for erythroid precursors


  • Pronormoblast; Rubriblast; Proerythroblast
  • Basophilic normoblast; prorubicyte; Basophilic erythroblast
  • Polychromatic (polychromatophilic) normoblast, Rubricyte, Polychromatophilic erythroblast
  • Orthochromic Normoblast, Metarubricyte, Orthochromic erythroblast
  • Polychromatic (polychromatophilic) Erythrocyte
• Erythroid Progenitors


  • Burst Forming unit- Erythroid (BFU-E)
  • Colony Forming unit - Erythroid (CFU-E)