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
