What does 50% Hb saturation mean?
Does it mean 50% Hb is fully saturated (4 oxygen molecules bound) and 50% Hb (no O2 bound)?
Does it mean 50% Hb is fully saturated (4 oxygen molecules bound) and 50% Hb (no O2 bound)?
On average, yes. I don't think anyone is in disagreement with that.Costanzo 5e, page # 214
*** By definition, P 50 is the PO2 at which hemoglobin is 50% saturated (i.e., where two of the four heme groups are bound to O 2 ).***
I disagree with this because according to that definition cyanosis cannot occur even at 25% Hb saturation as each Hb would have 1 O2 molecule-of course this is not true and the definition of cyanosis is inadequate oxygenation of blood, specifically referring to a high conc. of deoxyHb in capillaries (according to this costanzo definition-there is no deoxyHb hence no cyanosis which is false)On average, yes. I don't think anyone is in disagreement with that.
I disagree with this because according to that definition cyanosis cannot occur even at 25% Hb saturation as each Hb would have 1 O2 molecule-of course this is not true and the definition of cyanosis is inadequate oxygenation of blood, specifically referring to a high conc. of deoxyHb in capillaries (according to this costanzo definition-there is no deoxyHb hence no cyanosis which is false)
I think many physiology textbooks and articles oversimplify this concept
Please read what i said again, I never said Costanzo is engaging in falsification, i am saying cyanosis is referring to conc. of deoxyHb and that saying if 50% sat meant 2O2 on average per Hb, this would not make sense.You do realize that this is Step 1 forum AND saying Costanzo is engaging in falsification?