Genesis 2:7 says, "And the Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul." From the beginning of man's history on earth, breathing has been a basic act that demonstrates a large part of what it means to be alive. In fact, to determine if an unresponsive person is still living, breathing is the vital sign most often checked first. Our breathing patterns change without our conscious awareness to match our various activities such as studying, running, eating, or sleeping. It is possible to consciously control respiration, for example, when we hold our breath or when we speak. But still, as we well know, even after a minute or less of not breathing, something deep within us strongly objects and forces us to gasp for the breath of life. The cells of our body can't survive long without oxygen that is necessary to produce ATP to fuel living processes; our cells also give off carbon dioxide as a byproduct of ATP production. It is our respiratory system that allows us to inhale oxygen and deliver it to the bloodstream and also to exhale to remove excess carbon dioxide - both essential functions to sustain human life.