Haemopoiesis Flashcards
(42 cards)
Describe reticulocytes. hint: 5
- Larger than RBCS,
- lack central area of pallor,
- have blueish tint called polychromasia,
- has no nucleus but has RNA,
- takes 1 day before becoming an erythrocyte.
where does haemopoiesis begin?
in fetal liver and spleen then in adults it goes to the bone marrow
sites/timespan of erythropoiesis? (where does it occur & when)
- early foetal life: yolk sac
- 2nd to 7th month: liver, spleen and lymph nodes
- 7th month to birth: bone marrow
- childhood: bone marrow of all bones
- after 20 years: marrow of all flat bones eg. sternum, ribs, pelvis
how long does erythropoiesis take in humans?
4-8 days
stages of erythropoiesis?
- Pluripotent hematopoietic stem cell
- Proerythroblast ( Pronormoblast)
- Basophilic erythroblast (normoblast)
- Polychromatic erythroblast (normoblast)
- Orthochromatic erythroblast (normoblast)
- Reticulocyte (no nucleus)
- Erythrocyte
Requirements for erythropoiesis? hint: 5
- iron
- B12
- folate
- androgens
- cobalt salt
what is the normal red cell count in men and women?
- men: 4.5-6.5 x 10^12 /l; 5.5 +/- 1 x 10^12
- women: 3.5-5.5 x 10^12 /l; 4.8 +/- 1 x 10^12
what is the normal white cell count?
5-11 x 10^9/l
what is the normal platelet count?
250-400 x 10^9/l
where is erythropoietin produced?
mainly the kidneys, little in the liver
too much erythropoietin can cause what?
decreased heart rate cuz it can increase blood viscosity
give egs of when erythropoietic activity is high?
anaemia, renal failure and tumour-secreting erythropoietin
give egs of when erythropoietic activity is low?
severe renal disease and polycythaemia vera (type of bone marrow cancer-causes it to make too much rbcs)
Late BFUE and CFUE have erythropoietin receptors. T or F.
T- when stimulated they will proliferate, differentiate and produce haemoglobin
which growth factors act on stromal cells?
IL-1 & TNF
which growth factors act on pluripotent stem cells?
SCF (stem cell factor)
which growth factors act on early committed cells?
- IL-3
- IL-4
- IL-6
- GM-CSF
which growth factors act on late committed cells?
- IL-5
- G-CSF
- M-CSF
- EPO
when ineffective erythropoiesis is marked what is usually raised?
serum unconjugated bilirubin and LDH levels
how long does leucopoiesis take in humans?
10-14 days
what is the lifespan of white blood cells?
13-20 days
physiologic leucopoiesis can occur after?
exercise and adrenaline injection
what is the lifespan of granulocytes?
4-8 hours in the blood and 4-5 days in tissue
what is the lifespan of monocytes?
10-20 hours in blood and in tissue they become macrophages which live for several years
