Hematopoiesis Flashcards
What is the monophyletic theory?
all hematopoietic (precursor and unipotent) cells emerge from a single precursor (pluripotent stem cell)
when does hematopoiesis begin?
fetal life - yolk sac, liver, spleen
shortly before birth -> BM (femur)
describe the human bone marrow
- red = hematopoietic progenitors and developing cells
- yellow = inactive and mostly fat cells, macrophages, and mesenchymal cells
T or F. Yellow and Redmarrow exist in equal amounts but red marrow decreases with age
T! yellow marrow able to convert into active red marrow in times of increased need or demand
stromal or support cells
- endothelial cells: regulate compartments, cytokines
- adipocytes: fat cells, cytokines, growth factors
- macrophages: phagocytosis, cytokines
- lymphocytes: cytokines
- osteoblasts: bone-forming cells
- osteoclasts: bone-resorbing cells
this is secreted by fibroblasts and stromal cells and it forms support for HSC and developing cells
extracellular matrix
this is secreted in hypoxic states by the kidney interstitial cells to promote red cell production in the BM
EPO, a BM growth factor
secreted by liver and kidneys to develop megakaryocytes into platelets
thrombopoietin, a BM growth factor
cytokines
- CSF: colony-stimulating factors trigger differentiation of myeloblasts into granulocytes
- interleukins: differentiation/maturation/immunological functions
- interferons: differentiation/maturation
a BM growth factor
estrogen
promotes erythropoiesis, a BM growth factor
androgens
promotes erythropoiesis by promoting EPO production, a BM growth factor
thyroid hormone
promote erythropoiesis through increased Hb production
intrinsic vs extrinsic factors
intrinsic: genes and genetic composition of the cell
extrinsic: cytokines, growth hormones, hormones
how do we make use of extrinsic factor requirements to develop treatments for clinical applications?
- treatment of anemia and hematological disorders
- strengthen immune system of cancer and immunocompromised patients to protect against infection in chemotherapy and transplants
- increase yield of hematopoietic stem cells during apheresis
T or F. HSC can be differentiated from other progenitor cells based off light microscopy
F requires flow and cell marker analysis
CD45
leukocyte marker
CD34
stem cells and blasts
CD45, CD15
granulocytes
marginating pool
loosely localized to the walls of capillaries in tissues such as liver, spleen, lung
circulating pool
circulating in the blood vessels
physiological causes of leukocytosis
strenuous exercise
emotional stress
labour
increased epinephrine
pathological causes if leukocytosis
bacterial infection
neoplasms (leukemia)
following acute hemorrhage
tissue damage
drugs and toxins
inflammatory disorders
T or F. primary lymphopoiesis involves antigen-independent maturation
T!
CD3+
all T-cells
CD8+
naive or suppressor T cells
CD25+, CD4+
T regulatory cells
CD8+
cytotoxic T cells
CD3+, CD4+
T helper cells
CD44+
memory cells
when Hb becomes oxidized …
heinz bodies
iron oxidized
icky/ferric = unable to carry O2
