1.0 BLOOD & BONE MARROW: INTRODUCTION
The major cell components of the peripheral blood are:
- Red blood cells (erythrocytes), generated via the erythropoiesis or haemopoiesis pathway.
- White blood cells (leukocytes), generated via the myelopoiesis pathway.
- Platelets (thrombocytes), generated via cytoplasmic fragmentation of the large megakaryocytes.
1. Red blood cells
During fetal development haemopoiesis takes place in liver and spleen and bone marrow. At birth bone marrow remains the main site of blood cell production. The erythropoiesis occurs in the erythroblastic islands in the bone marrow in several differentiation steps from a pluripotent stem cell into the following morphological stages:
- proerythroblast,
- basophilic erythroblast,
- polychromatic erythroblast intermediate normoblast)
- orthochromatic erythroblasts (late normoblast)
- reticulocyte
- erythrocyte in the peripheral blood
2. White blood cells
The white blood cell types are
(1) Granulocytes, i.e. neutrophils (40-75%), the eosinophils (5%). the basophils (0,5%) , (granulopoiesis or myelopoiesis).
(2) Lymphocytes (20-50%) (see section 2.0 Lymphatic organs introduction and section 2.1 Lymphatic organs images)
(3) Monocytes (1-5%).
The granulopoiesis occurs in the bone marrow via the following differentiation steps from a pluripotent stem cell to:
- myeloblast,
- promyelocyte,
- myelocyte,
- metamyelocyte and
- band (stab) cells, followed by
- segmented cells in the peripheral blood.
The monocytes are generated via the bone marrow precursors monoblasts and promonocytes which further differentiate into monocytes and tissue macrophages that circulate in several organs such as liver (Kupffer cells), lung (pulmonary alveolar macrophages), etc.
3. Platelets or thrombocytes
The thrombocytes are created by cytoplasmic fragmentation of the huge megakaryocytes. The precursor is the megakaryoblast in the bone marrow . This cell has reduplicated its nuclear and cytoplasmic content several times (huge polyploidy).
4. Deviating blood cells
- Mott cell: See: 1.1 POJA-L540-HV
- Giant plasma cell: See: 1.1 POJA-L541
- Flaming plasma cell: See: 1.1 POJA-L539-HV
- Leukemic monomorph bone marrow smear: See: 1.1 POJA-L553+520
- Granuloma in bone marrow: See: 1.1 POJA-L864-HV
- Toxic granulation and vacuolization in neutrophilic myelocytes. See: 1.1 POJA-L-589-HV
- Howell bodies in reticulocytes. See: 1.1 POJA-L504-HV
COPYRIGHTS
All slides of which the legends are marked with the added characters -HV- are contributed by Henriette Verhofstad and bear a copyright-logo with her name. They are part of the POJA-collection. Therefore, Henriette Verhofstad, Lambert G. Poels and Paul H.K. Jap are the primary persons to be addressed for those images. The copyright of all slides and legends marked as POJA-HV – and/or H. Verhofstad are hold by Henriette Verhofstad, (M.I.A.C. and Former head of the Division of Cytopathology and Hemato-morphology of the Viecuri Hospital , Venlo, The Netherlands).
All other images (not marked with the extension -HV- ) are contributed by Poels and Jap and bear the UMC-POJA-copyright-logo.
All rights reserves worldwide for the POJA collection are hold by L.G. Poels and P.H.K. Jap and Radboud University Medical Center (Radboud UMC Nijmegen). No one may modify, copy, distribute, transmit, display, or publish any materials contained in the POJA collection without prior written permission of the authors Poels and Jap or the UMC St Radboud. Any commercial use of the POJA collection is forbidden. POJA images are partly deposited in the Health Education Assets Library (HEAL database) as well as in the MedEdPortal/AAMC database).
COPYRIGHTS
All slides of which the legends are marked with the added characters -HV- are contributed by Henriette Verhofstad and bear a copyright-logo with her name. They are part of the POJA-collection. Therefore, Henriette Verhofstad, Lambert G. Poels and Paul H.K. Jap are the primary persons to be addressed for those images. The copyright of all slides and legends marked as POJA-HV – and/or H. Verhofstad are hold by Henriette Verhofstad, (M.I.A.C. and Former head of the Division of Cytopathology and Hemato-morphology of the Viecuri Hospital , Venlo, The Netherlands).
All other images (not marked with the extension -HV- ) are contributed by Poels and Jap and bear the UMC-POJA-copyright-logo.
All rights reserves worldwide for the POJA collection are hold by L.G. Poels and P.H.K. Jap and Radboud University Medical Center (Radboud UMC Nijmegen). No one may modify, copy, distribute, transmit, display, or publish any materials contained in the POJA collection without prior written permission of the authors Poels and Jap or the UMC St Radboud. Any commercial use of the POJA collection is forbidden. POJA images are partly deposited in the Health Education Assets Library (HEAL database) as well as in the MedEdPortal/AAMC database).