Erythropoiesis Flashcards
(30 cards)
what engulfs old RBCs
phagocytic cells of liver and spleen
what are globular haemoglobin protiens broken into
amino acids which enter the blood stream
what is the substrate of bilirubin
haem group (minus iron) is converted to bilirubin
where is bilirubin transported to
the liver and secreted into bile
what does bilirubin do to urine and faeces
colour them
how is iron recycled
it binds to transferrin
what is erythrocyte production regulated by
enzyme erythropoietin (EPO)
when is EPO released
when there is reduced oxygen carrying capacity
where is EPO released from
the kidneys
what does EPO do
production of RBC by red bone marrow
describe the cells in erythropoiesis from stem to mature cell
proerythroblast, polychromatic, orthochromatic, erythythroblast extrudes nucleus, reticulocyte, mature erythrocyte
where is proerythroblast derived from
myeloid stem cells
what is the diameter and thickness of a RBC
8um diameter, 2um thick at edge and 1um in the centre
what is haematocrit
volume of RBCs as % of total blood volume
how is ATP synthesised in RBC
via glycolysis as they have no mitochondira
apart from glycolysis what is another pathway for metabolism of glucose
hexose monophosphate shunt
what does the hexose monophosphate shunt produce which is important
NADPH (this is important for maintenance of adequate levels of reduced glutathione
what does glutathione do
combat oxidative stress
what are reactive oxygen species
free radicals that are highly reactive as they have unpaired electrons
which ion is particularly reactive
superoxide anion o1-
what is the main reactive species
hydrogen peroxide
what is required to maintain adequate levels of reduced glutathione
NADPH
what is produced when po2 is reduced
2,3 BPG
what does 2,3 BPG do
release O2 from Hb
