Structure + Function of Normal Red Cells Flashcards
describe the shape of an RBC
biconcave disc
what cell structures do RBC’s lack?
nucleus
mitochondria
describe the structure of the RBC’s membrane
lipid bilayer containing proteins to make it flexible
what structure is important to provide energy and keep water out of RBC’s?
the sodium potassium pump
what forms HbA?
two alpha and two beta subunits
what forms HbF?
two alpha and two gamma subunits
what does oxygen bind to in Hb?
Fe2+ in the haem group
what is the role of Hb?
deliver oxygen to tissues
also acts as a buffer for H+ and transports CO2
when should Hb let go of oxygen/
when pO2 is low in the tissues
describe the shape of the oxygen Hb dissociation curve
sigmoidal
what effect does shifting the oxygen Hb dissociation curve to the right have?
more oxygen delivered to the tissues
name three molecules that can interact with Hb and shift the oxygen Hb dissociation curve to the right
H+
CO2
2,3-BPG
how is 2,3-BPG generated?
via the rapapport lubering shunt
a side process in glycolysis
what happens to 2,3-BPG in chronic anaemia and why?
becomes elevated in an attempt to compensate for the anaemia
what is erythropoeisis?
red cell production
where does red cell production occur?
the bone marrow
what hormone regulates red cell production?
erythropoeitin produced by the kidneys
describe the effects of erythropoietin if oxygen saturations drop
hypoxia sensed by the kidneys
erythropoietin produced
red cell production stimulated
where does red cell destruction occur?
spleen
also the liver
what is the average lifespan of a red cell?
120 days
what happens to RBCs after their lifespan is up?
taken up by macrophages + broken down
what happens to the contents of red cells after being broken down by macrophages?
globin chains recycled to amino acids
haem group broken down into iron and bilirubin
