Haematopoiesis Flashcards
RBCs:
1. no. in body?
2. lifespan?
3. how many per day?
- 20-30 trillion
120 days
4000million per day
3 reasons RBC count might need to change
- sudden need e.g. haemorrage, injury
- temp need e.g. at higher latitudes
- chronic need e.g. compensating for disease like Hb disorders
how many WBCs per day made
10,000 milion per day
how many platelets/ day made
400,000 million (dont last long)
too many platelets can cause what
gangrene, blocked vessels
OG stem cell
multipotent haematopoietic stem cell
partially differentiated cuz only blood cells
2 ways stem cells can differentiate
new precursors to blood cells
self renew to maintain stem cell number
why is proliferating and differentiating pool of stem cells so importnat
control rate of production
how many mature cells does a stem cell make
500,000 (19 cycles of proliferation)
what 2 cytokines affect early stem cell
- stem cell factor
- interleukin 3
what 3 cytokines act on cells further down
- thrombopoietin
- erythropoietin
- GM-CSF
what cytokines control function of cells (ie act on more mature cells to specialise them)
G-CSF
M-CSF
for a steady state, how should initial stem cells divide
- one should differentiate/proliferate
- other should self replicate
(all depends on needs of body)
Stem cell niche
- cytokines
- adhesive proteins
- supporting stromal cells
process from myeloid precursor to neutrophil
common myeloid precursor
myeloid blast cell
promyelocyte
myelocyte
metamyelocyte
neutrophil
