Blood and hematopoiesis • Blood composition • Formed blood elements (blood cells and platelets) • Development of blood (hematopoiesis) Blood and hematopoiesis ♂ 42 – 52 % ♀ 37 – 47 % 55 % plasma 90 % H2O 7 % plasma proteins 3 % aminoacids, sugars, lipids, hormones, electrolytes 45 % formed elements (cells and platelets) Blood composition Plasma Buffy coat (leukocytes, platelets) Erythrocytes (red blood cells) Hematocrit LEUKOCYTES GRANULOCYTES (polymorphonuclear cells) AGRANULOCYTES (mononuclear cells) neutrophilic 10 - 12 m eosinophilic 12 - 14 m basophilic 8 - 10 m lymphocytes 6 - 8 / 10 -12 m monocytes 12-20 m THROMBOCYTES ERYTHROCYTES Formed blood elements 7.2 - 7.6 m 2 – 4 m Blood smear preparation newborns toddlers bbraun.com Blood smear is fixed (methanol, 3-5 min) and then stained (usually the panoptic stain by Pappenheim) single erythrocytes clumps of erythrocytes thin dense cell density Erythrocytes (1) and eosinophilic granulocyte (2) Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x 1 2 Erythrocytes (SEM) Erythrocyte in capillary (TEM) Neutrophilic granulocyte – band (B) and segment (S), thrombocyte () B S Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Neutrophilic granulocyte – band B Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Neutrophilic granulocyte – segment (S) S Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Neutrophilic granulocyte – segment, lymphocyte (Ly), thrombocytes () S Ly Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Eosinophilic granulocyte (1), neutrophilic granulocyte – segment (2) 1 2 Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Eosinophilic granulocyte Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Eosinophilic granulocyte (TEM) Basophilic granulocyte Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Lymphocyte Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Lymphocyte (TEM) Monocyte (1), lymphocyte (2) 1 2 Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Monocyte (1), neutrophilic segment (2) 1 2 Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Monocyte (TEM) phagosomes Thrombocytes (platelets) Peripheral blood smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Thrombocyte (TEM) Hematopoiesis  Hematopoietic stem cell - slowly cycling, morphologically indistinguishable  Progenitors of hematopoietic lineages (CFU-E, CFU-M, CFU-G, CFU-Meg etc.) - rapid proliferation, morphologically indistinguishable  Precursor cells - early stages still proliferate, but as differentiation progresses, they exit cell cycle - clear morphological hallmarks  change in cell size  change in cytoplasmic staining  specific cell components appear  condensation of nuclear chromatin and change of nuclear morphology or nuclear extrusion (enucleation) 1. Proerythroblast 2. Basophilic erythroblast 3. Polychromatophilic erythroblast (polychromatic) 4. Orthochromatophilic erythroblast (orthochromatic) 5. Reticulocyte 6. Erythrocyte ERYTHROPOIESIS Substantia reticulofilamentosa Proerythroblast Basophilic erythroblast Polychromatophilic erythroblast Orthochromatophilic erythroblast ERYTHROPOIESIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Proerythroblast Basophilic erythroblasts Polychromatophilic erythroblasts Orthochromatophilic erythroblasts ERYTHROPOIESIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Orthochromatophilic erythroblast: enucleation (extrusion of nucleus) MITOSIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x MITOSIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x substantia reticulofilamentosa ERYTHROPOIESIS - reticulocyte Bone marrow smear, brilliant cresyl blue staining, immersion oil, 1000x GRANULOPOIESIS Myeloblast Promyelocyte Myelocyte Metamyelocyte Granulocytes Myeloblast Neutrophilic myelocyte GRANULOPOIESIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Eosinophilic myelocyte Neutrophilic myelocyte Promyelocyte Promyelocyte GRANULOPOIESIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x GRANULOPOIESIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Promyelocyte GRANULOPOIESIS Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x THROMBOPOIESIS • endomitosis  development of polyploid nucleus • demarcation membrane system • megakaryoblast  promegakaryocyte  megakaryocyte  thrombocytes MEGAKARYOCYTE Promyelocyte Myelocyte Ortochromatophilic erytroblast Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x MEGAKARYOCYTE Bone marrow smear, panoptic staining (method of Pappenheim), immersion oil, 1000x Blood and hematopoiesis Slides: Peripheral blood and bone marrow smears Electronograms: Atlas of Cytology and Embryology https://www2.med.muni.cz/histology/multimedia-and-textbooks/