At 12:54 16 August 2005, Hl Falbaum wrote:
There are other, important, limiting factors. The alveoli
need to exchange
two gases--CO2 and O2 and pressure gradients are needed
for this. The fly in
the ointment is that water vapor pressure in the alveoli
remains near
constant at 47mm Hg (Torr). The CO2 comes from diffusion
across the
capillary-alveolar barrier, from the blood, and therefore
remains somewhat
high and at 30,000 ft is about 30 mm Hg. So the O2
must ovecome this
pressure and about 30 mm more to get into the blood
effectively. So unless
the O2 is above about 107 mm Hg you don't get enough
in your blood to do you
any good.

--
Hartley Falbaum,


Good for you Hartley !

The alveolar 'head of steam' is, very much, the ******
in the gas exchange woodpile at altitude.

OOPS - PC - as if I care !!

s(a)ta13nski.