Oil system myths

How do explain oxygen getting in your lungs? You can’t grab a hand full of it and place it in your mouth? Your diaphragm moves downward, your auxiliary muscle in your chest wall expands your chest and all this creates a negative pressure causing the 14.7 atmospheric at sea level makes the air around us rush into our lungs. And life results.

Most people think they have trouble breathing at high altitudes because there is less oxygen in the air . NOT