Why does Oxygen displacement (via inert gas) knock people out in seconds but people can hold their breath much longer?
In: Biology
Gas exchanges across the lung/blood membranes according to the relative concentrations in the air and blood. Hold your breath and the lungs are filled with air with 21% oxygen which goes down to about 15% as some of it moves into the blood, so they are reasonably balanced.
Fill the lungs with inert gas with no oxygen and the concentrations will tend to equalise, it will actually remove oxygen from the blood, dropping the level very quickly and causing oxygen deprivation in the brain.
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