Hematopoeisis Flashcards
lifespan of neutrophils
1-2 days
lifespan of RBC
120 days
lifespan of platelets
8-9 days
factors for inducing neutrophil development
CM-CSF, G-CSF, IL3
RBC factor (hormone)
Epo- from the kidney
Plt factor
TPO = thrombopoietin- from the liver
when does the liver do hematopoeisis
1-9 months of gestation (+ ~3 months after birth)
what else controls hematopoeisis in fetal life
yolk sac
liver
spleen
bone marrow
where is red marrow located
ribs, vertebrae, pelvis
where is yellow marrow located
long bones- arms and legs
when is yellow converted to red marrow
in situations of blood loss/trauma
osteoblastic/periarteriolar niches
quiescent stem cells
resistant to 5FU
perisinusoidal niches
cycling stem cells
killed by 5FU
what anchors cells in the niche?
c-kit, integrins, other surface molecules
what causes eosinophilic-looking RBC’s
Hb accumulation
normal retic count
1-2% of RBC’s
how long for RBC maturation
7 days
when are retics normally increased (physiologically appropriate)
in bleeding or hemolysis
where do T cells mature
thymus
where do B cells mature
germinal centers of lymphoid follicles
platelet alpha granules
PDGF, platelet factor 4, clotting factors
which lineages involve FOG and GATA-1
erythroid and megakaryocytic lineages.
they are transcription factors
proto-oncogenes promote
high proliferation
tissue growth
examples of proto-oncogenes
Ras, Wnt, Myc, Shh, Notch
tumor suppressor genes promote
low proliferation
sensecence and aging
examples of tumor suppressor genes
p53, Rb, BRCA
small intestine has robust activation of ___ and low expression of ___
p53 pathway
Bcl2
colon has high levels of
Bcl2
what about melanocytes causes greying of hair?
premature differentiation after DNA damage leading to depletion
dyskeratosis congenita cell aging BM failure cancer are all consequences of...
telomere shortening and genetic instability
