resp-6 gas transport in blood Flashcards
how is most oxygen carried in blood
hemoglobin
lowest and highest po2 in the system
arteriol-100 Po2
venous-40 PO2
what is normal Hb/ml blood?
15Hb/100mL blood
what is Hb saturation
% available Hb binding sites that have O2 attached
arterial=97.5%
venous=75%
what is the most important determinant of Hb saturation
arterial PO2 (how much O2 bound to Hb)
why is there the plateau in sigmoidal dissociation curve
saturation of Hb with O2 stays high with a range of alveolar pO2 (safety)
why is the steep portion of the Hb curve beneficial
to enhance O2 unloading due to compounds produced in tissues (pH, tempt)
what is anemia
reduction in Hb in blood
what is polycthemia
increase Hb in blood OR reduction in blood volume which increases [Hb]
how does changes in Hb concentration affect the O2 diss. curve
they all still reach 100%, similar curves
less [Hb] reach saturation with less o2 conc
where does the curve shift when CO binds
to the left (less unloading in tissue)
does o2-Hb contribute to po2 value
no!! it is bound so it does not count in the pressure
how is oxygen delivered to peripheral tissue
high [o2] in blood, low [o2] in cells, movement by pressure gradient. as o2 released, Hb loses affinity and then releases more
curve shift to right
how does it affect affinity and unloading
less affinity to O2
more unloading
curve shift to left
how does it affect affinity and unloading
more affinity to O2
less unloading
how does DPG affect curve
shifts to right (less affinity, more unloading)
how is CO2 mostly carried in the blood
as bicarbonate (HCO3-)
what is the chloride shift
hco3- leaves RBC in exchange for Cl- going in
what enzyme is required for CO2 to bind to Hb
none
does deoxyHb or oxyHb have a higher affinity to CO2
why this good
deoxyHb
CO2 helps unload O2
whats a carbamino compound
when CO2 is bound to Hb
does deoxyHb or oxyHb have a higher affinity to CO2
deoxyHb
why isnt blood super acidic even though H+ is made
large portion of H+ is bound to Hb (not dissolved in RBC or plasma)
who has a key role in buffering H+ production in peripheral tissues and capillaries
Hb!
what happens in hypoventilation
co2 production> co2 elimination, high PCO2 and high H+
what does hypoventilation cause
respiratory acidosis
what happens in hyperventilation
CO2 elimination > CO2 production, low PCO2 low H+
what does hyperventilation cause
respiratory alkalosis
what is metabolic acidosis
high H+ in blood independent of changes in PCO2
metabolic alkalosis
decrease H+ in blood independent of changes in PCO2
