Breathing… we do it all day long, every day, and yet we never even put a thought to it. But so many respirator users do not understand the basics of how we get the air (more importantly, the oxygen in the air) into our lungs so that it can enter our bloodstream for survival. As I said, breathing is an involuntary act – meaning we are not sucking air into our lungs. In the simplest terms, we use the 14.7 psi atmospheric pressure to push the air into our lungs, which have relaxed and created a vacuum; it is the pressure differential that moves the air into our lungs – NOT us sucking it in. Here is some of the best (simplest) medical language explaining this I have ever seen. The author is unknown, but I am pretty certain this came out of a medical textbook…