Lesson 13: Topic 8 and 9 - O2 Transport and CO2 Transport Flashcards
a PO2 of 100mmHb will likely result in?
all the Hb or 98-99% to be fully saturated with oxygen
you can have a slight reduce in PO2 but still be? (from an O2 hemoglobin saturation POV)
fully oxygenated (typically around 60mmHg)
can breathing too much oxygen be hurtful?
yes
- you can have an inflammatory response
is PO2 low or high on mount everest?
low
what happens if PO2 is too low?
there is not going to be enough sufficient oxygen available for aerobic metabolism and to sustain life
someone with anemia has less?
hemoglobin
why does someone with anemia have the same dissociation curve as someone without anemia?
because while there is less hemoglobin. they are still fully saturated. the only difference is that there concentration of Hb in a given amount of blood
what are some physiological factors that can change the O2 dissociation curve?
- increased arterial PCO2
- Increased acidity (H+) or low pH in the blood
- increased temperature of the blood
those three are causing a push away from homeostasis so if any of these happen the body is going to adapt to try to maximize the amount of oxygen that is going to get to the cell
what happens if a cell gets acidic?
it becomes non-functional
when do we see the three physiological factors that can change the O2 dissociation curve?
heavy exercise
- we get a rightward shift in the curve
the rightward shift in the dissociation curve is a mechanism to?
help unload oxygen from the hemoglobin to allow increased oxygen diffusion into the cell
- called the Bohr effect
at a given PO2 in the setting of a rightward shift, the drop in saturation of the given PO2 reflects?
more unloading of oxygen
at any given Bohr effect, at any given level of PO2 ________________________.
there will be more unbinding , or desaturation of oxygen from hemoglobin
where is CO2 being produced?
at the tissue/cellular level and we pump it back up in the venous circulation and expire a lot of it
why is it impossible for CO2 to get out in the dissolved blood via hemoglobin?
because most of the oxygen is already bound to the hemoglobin
what is the mechanism that allows for effective CO2 transport from the cell to the atmosphere?
bicarbonate
the byproduct of internal respiration is?
- increased CO2
- water
- energy
how do we measure our PCO2 in the blood?
the plasma
how is CO2 transported?
- 10% dissolved in plasma
- 30% bound to Hb (HbCO2; carbamino Hb)
- 60% converted to bicarbonate (HCO3-)
what is the bicarbonate equilibrium reaction?
CO2 + H2O (produced in the cell) <-carbonic anhydrase-> H2CO3 <——-> HCO3- + H+
why do we not want to have too much hydrogen ions in the blood?
because it can disrupt internal cellular respiration
how is hydrogen ions mostly carried?
most is carried bound to DeoxyHb (hemoglobin)
- they combine to create hydroxyhemoglobin (HbH)
at the lung where O2 is loaded onto Hb, H+ is then _____ from __ and combines with _____.
then released from Hb and combines with HCO3
