Anatomy and physiology for polygraph examiners
Joel M. Reicherter, in Fundamentals of Polygraph Practice, 2015

I learned from this text important functions of the respiratory system along with its close relationship to the cardiovascular system. The respiratory system removes oxygen from the air and eliminates carbon dioxide through breathing, cooperating with blood to carry these gases all around the body. I also learned that the airway, known as the conducting zone or dead air space, possesses adapted features to filter the inhaled contaminants from the lungs. These include cells that secrete mucus and ensnare contaminants along the pathway, warming and moistening the air to improve oxygen availability to the blood. That’s just another way of saying the genius behind the design of the respiratory system for efficiency and defense against infections.