Erythropoiesis Flashcards
what do too few RBC’s lead to
tissue hypoxia (can’t get enough oxygen)
what do too many blood cells increase
tissue viscosity
what hormone makes the stem cell commit to becoming a red blood cell
erythropoietin
what’s the primary source of erythropoietin
kidneys
what cells does erythropoietin act on
early progenitor cells
2 things EPO do
rapid maturation of committed marrow cells
increased circulating reticulocyte count in 1-2 days
what enhances epo production
what sex have higher rbc count
testosterone
males
what stimulates kidneys to produce erythropoietin
low oxygen levels (hypoxia)
2 causes of hypoxia
decreased rbc numbers due to haemorrhage/ increased destruction
insufficient haemoglobin per rbc (iron deficiency)
reduced oxygen availability (high altitudes)
what’s does erythropoietin promote in red bone marrow
erythropoiesis
how long do new erythrocytes survive in blood stream
about 120 days
3 main dietary requirements for erythrocytes
nutrients (amino acids, lipids, carbohydrates)
iron
vitamin b12
folic acid
what’s 65% iron found in
rest?
haemoglobin
liver, spleen, bone marrow
what’s type of iron is toxic
free iron ions
what are free iron ions stored as in cells
ferritin
