Hematopoiesis Flashcards
Define Hematopoiesis
Predominantly occurs in the marrow leading to the formation of RBC, WBC, platelets, and other cells.
Where are the sites of hematopoiesis in the following situations:
- Prenatal
- Fetal
- Postnatal
- Prenatal: Yolk Sac. Done by 3 months
- Fetal: Liver/Spleen Month 2-7
- Postnatal: Bone marrow (becomes more and more localized to axial skeleton
Define: Extramedullary hematopoiesis
Hematopoiesis outside bone marrow area after birth
Define: Differentiation/maturation
progress of cell lineage from less mature types (blasts) to more mature (segs)
Define: Self-renewal
Production of daughter cells that are completely unchanged they cease to proliferate but can later
What does myeloid refer to?
non-erythroid, and non-lymphoid cells
What does lymphoid mean?
Refers to T cells, b cells and NK cells
List the order of cells from least mature to more mature.
- Multipotential Hematopoietic Stem Cells (HSC)
- Pluripontent Stem Cells (Colony forming unit (CFU))
- Progenitor Cells
- Precursor Cells
What cells do multipotential hematopoietic stem cells produce?
Gives rise to all lymphoid and myeloid elements
What cell line is unable to self-renew, but can still divide?
Precursor cells
Name the following hematopoietic growth factors (HGF) for the following:
- Erythrocytes
- Platelets
- Granulocytes
- Monocytes
- Eosinophils
- Basophils
- Erythropoietin (Epo)
- Thrombopoietin
- Granulocyte-Monocyte Colony Stimulating Factor (GM-CSF) or Granulocyte Colony Stimulating Factor (G-CSF)
- Granulocyte-Monocyte Colony Stimulating Factor (GM-CSF) or Monocyte Colony Stimulating Factor (M-CSF)
- Interleukin -5 (IL-5)
- Interleukin-3 (IL-3)
Name and describe each step of erythrocyte maturation.
- Pronormoblast-Larege nucleus with one-two nuclei, lots of RNA so stains intensely blue
- Basophillic Normoblast- Lighter colored perinuclear halo course condensation of nucleus
- Polychromatophilic normoblast- Purplish blue due to hemoglobin nucleus smaller course
- Orthochromic Normoblast- Red-orange pyknoctic nucleus
- Reiculocyte: Anucleated, ribosomes and mitochondria polychromatophilic: bluish purple
- Erythrocyte: RNA degraded; orange-red color
Name and describe each step of granulocyte maturation
- Myeloblast: High nuclear: cytoplasmic ratio. One or more nucleoli blue with lots of RNA and no cytoplasmic granules
- Promyelocyte: Nucleoli present course chromatin. Purple granules in blue cytoplasm
- Myelocyte. Appearance of 2nd lavender granules. Nucleoli less conspicuous CAN DIVIDE!!!
- Metamyelocyte: Primary granules are gone. Pinkish/purple hue. Nucleus indented
- Band: Horseshoe shaped nucleus
- Segmented Neutrophil: 2-5 segmented lobes of nucleus connected by thin chromatin strand
Name and describe each step of eosinophil maturation
A mature eosinophil has red/orange cytoplasm and a nucleus that contains condensed chromatin. The nucleus is also segmented into two round ovals
Name and describe each step of basophil maturation
Mature basophils are lobular but the nuclues is nonsegmented. The cytoplasm contain blue/purple granules.
Name and describe each step of megakaryocyte maturation
- Megakaryobasts- Large nucleus with nucleoli basophilic cytoplasm
- Promegakaryocyte- Endoreplication. Nucleus is lobulated and chromatin condensed. Intense blue color
- Megakaryocyte- lobulated, endoreplicated nucleus. Cytoplasm contains fine granules and is purple
- Platelet- Anucleated fragments of megakaryocytes. Purplish
Name and describe each step of monocyte/marcrophage maturation.
- Monoblast: Nucleus slightly indented; fine chromatin and nucleoli. Cytoplasm bule with no granules
- Promonocyte: chromatin more condensed; one or more nucleoli. Red/purplish granules in cytoplasm
- Monocyte: Largest cell in periphery. Nucleoli absent. Cytoplasm blue ground glass appearance red/purple granules
Describe the cellularity of bone marrow
50% cellularity normal
Cellularity decreases with age
What is a normal Myeloid:Erythroid ratio in the marrow?
3:1
What would be a normal appearance of bone marrow: heterogenous or homogenous?
Heterogenous. Homogenous can be indicative of acute leukemia