Orthochromatic erythroblasts

In man the synthesis of hemoglobin occurs principally in erythroid cells in the bone marrow. In accordance with the generally accepted Unitarian theory of hematopoiesis, primitive stem cells in the bone marrow give rise to cells of the erythroid, myeloid, and platelet series. In erythropoiesis the stem cell differentiates to form the proerythroblast. Successive mitotic divisions yield basophilic, polychromatophilic, and orthochromatic erythroblasts. Subsequent maturation to normoblasts, reticulocytes, and mature erythrocytes involves no further mitotic division. 

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