Hematopoiesis Flashcards
which is more abundant in the bone marrow - granulocytes or RBCs? why?
granulocytes - much shorter life span
what is the role of the bone marrow stromal cell?
maintenance and differentiation of HSCs
what is the relationship between stromal cells and HSCs as the HSCs develop?
the more mature a HSC gets, the less firmly it binds to the stromal cells
which molecules are responsible for driving cell differentiation pathways?
cytokines
GCSF is released by what cell type?
macrophage
where is GCSF released?
site of inflammation
what does GCSF do once released at a site of inflammation?
circulates to bone marrow so stimulate production / release of neutrophils
EPO is produced / released by what cell type?
peritubular interstitial cells of kidney
EPO is produced in response to what condition?
hypoxia
what does EPO do once released by the kidney?
circulates to bone marrow to stimulate production and release of RBCs
what is the role of TGFB on the bone marrow?
decreases cell surface receptors for growth / differentiation cytokines
what is the clinical utility of GCSF?
- BMT - mobilizing stem cells to blood for IV draw
2. stimulates granulopoiesis following chemotherapy induced marrow suppression
what is the clinical utility of granulocyte monocyte colony stimulating factor (GMCSF)?
- increases myeloid cell recovery in bone marrow transplantation patients
- more toxic than GCSF
what is the clinical utility of EPO?
increases RBC mass in renal insufficiency-induced anemia
extramedullary hematopoiesis takes place in which organs?
spleen and liver
what are the maturational characteristics of erythropoiesis as a cell matures?
- cell size decreases
- nucleus:cytoplasm ratio decreases
- nucleoli decrease in number and eventually disappear
- lighter blue (less RNA)
what must occur before a metarubricyte becomes a reticulocyte?
nucleus extrusion
what is the normal “home” for neutrophils?
peripheral blood
where do B and NK cells differentiate?
entirely in bone marrow
fully mature B cells have which immunoglobulin markers?
IgM and IgD
what is the T cell maturation sequence?
- bone marrow - prothymocytes
2. thymus - maturation / differentiation into T lymphocyte subsets
where do T cells go once they leave the thymus?
populate lymphatic organs
what is endomitosis?
nuclear mitosis without the cytoplasmic divisions
thrombopoiesis is stimulated by what?
thrombopoietin
what is the “absolute count”?
provides QUANTITY of each cell type per unit volume
what is the “differential count”?
provides RELATIVE count (%) of each cell type
what is the normal reticulocyte count?
1%
