Posted by Gene Dahl on
URL: https://www.shado-forum.com/Air-supply-tp1505209p1505245.html

I agree with everything you wrote except for the following:

davrecon wrote:

> Your body is actually un-able to detect the lack of oxygen in the air it
>breathes, it only goes by the CO2 content to regulate respiration. So if you
>were to rebreath the same air, but only scrubbing out the excess CO2 w/out
>replacing the oxygen, you would simply pass out, blissfully unaware that you
>were suffering from oxygen starvation. Many inexperienced general aviation
>pilots have had accidents in this way by not going on the bottle at high
>altitudes.
>

In actual fact, the body has receptors for O2 as well as CO2. If the
atmosphere is low on O2 percentage, a person will begin to
hyperventilate to increase the amount of oxygen intake. If there is too
much CO2, a person will hyperventilate to remove the excess CO2.
However, some people with lung disease do not change their breathing
pattern if they have too much CO2, and chronically have an excess up to
twice what a "normal" person has. The only regulating factor for them is
the O2 receptors. In my experience as a Respiratory Therapist, I
actually know a person who committed suicide by increasing the amount of
oxygen he was breathing and, since his body did not feel he needed to
breathe, he quit breathing and literally "went to sleep" and died when
his CO2 reached a fatal limit.