Granulo- / Hematopoiesis

Hematopoiesis Proerythroblast: Basophilic cytoplasm, large quantities of euchromatic chromatin, nucleoli evident 3-5, Nucleus appears red/violet, cytoplasm somewhat blue with gray spots, Nucleus makes up about 85 % of cell volume, cell is bigger than surrounding erythrocytes. Basophilic erythroblast: strongly basophilic cytoplasm -> dark violet/blue, nucleus is visibly smaller with condensed (heterochromatic) chromatin- dark spots, Polychromatic erythroblast: Different colours visible in the cell, nucleus is reddish black, cell is smaller than in the stage before, cytoplasm appears lighter, last stage with mitotic division. Orthochromatic erythroblast: nucleus nearly black with small pink spots, cytoplasm a bit darker than that from surrounding erythrocytes, cell again smaller, Reticulocyte: appearance as erythrocyte, no nucleus, small amount of polyribosomes present. While maturation, the amount of hemoglobin (basic molecule -> eosinophilic) increases, while the amount of polyribosomes in the cytoplasm, which account for the basophilia in the early stages of maturation, decreases. The nucles shrinks and gets more heterochromatic with time, until it is released -> pyknotic nucleus. The increased heterochromatic appearance is a sign for the decreasing of metabolic activity of the cell: That means that the hemoglobin molecules must reach their defined amount, before the nucleus is expelled! Since there is then no need for polyribosomes, which synthesize hemoglobin, their concentration decreases with time. Keep in mind that the nucleoli a responsible for the synthesizing of polyribosmes. Granulopoiesis Final products: netrophils, eosinophils, basophils, which differ in their amount of the different granules. All arise from the same precursor cell, the myeloblast. − Relatively big nucles – smaller in relation of volume to size than in proerythroblast-, with light area called halo. Chromatin appears euchromatic and nucleoli are evident, cytoplasm is basophilic -> blue/violet Promyelocyte: nucleus has a light red appearance, first azurophilic granules are produced and appear as red dots ( nearly same colour as nucleus) in the cytoplasm, which is light violet with white/ gray areas. First differention is possible from this stage on. Eosinophilic myelocyte: nucles is acentric (shifted to the cell periphery) and more heterochromatic, cytoplasm full of red granules (lighter than nucleus), specific granules are synthesized. Eosinophilic metamyelocyte: Nucleus is going to be bilobed, the red granules are still persistent, Eosinophilic stab cell: a bit bigger than erythrocyte, bilobed nucleus is somewhat pressed to the cell periphery, whole cell appears as in the preceeding stages, red.

Neutrophilic myelocyte: light violet cytoplasm, small amount of azurophilic granules, synthesizement of secondary granules, nucleus is acentric with light areas, halo between cytoplasm and nucleus. neutrophilic metamyelocyte: nucleus (60 % of cell size), halo, cytoplasm has light appearance, neutrophilic stab cell: nucleus is going to be lobes- looks like half moon, chomatin is more condensed – areas of dark colour evident, cytoplasm appears nearly white, The 'appendage' to one of the lobes is the drumstick, the inactive female X chromosome and therefore only visible in blood cells of females! Basophil maturation.......self explaining.....have a good guess...... big dark secondary granules staining intensely with the methylene blue thus basophilic- acidic content. How to memorize the names ? Myelo-blast Pro (before)- myelocyte, only azurophilic granules .... myelocyte, cell with both types of granules meta (changing)- myelocyte: change of shape of nucleus Keep in mind: No bone marrow smear, no cells in intermediate states ! If no granules evident-> agranulocytes, only 2 possibilities: monocytes and lymphocytes. They have azurophilic granules but in smaller concentration. If granules: neutrophil, basophil or eosinophil Basophilic structures are stainedark blue. Eosinophic structures pink/red.

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