This question is quite easy. Your body require in essence three things oxygen, CO2 elimination (the brain is actually. Pretty much a selfish and only care about staying a comfortable pH range). When you breathe in no that all that air is able tel be diffussion in the blood stream. aveoli which are responsible fo getting blood oxygen out give out acidic CO2. One thing however isbthat we don't have a functional lung and airway. A lot is deadspace. This isbwhy there are folds so that more air can be processed. However without a good aveoli patudnt can become ox toxicity..
