Briefly explain the functions of the organs of the respiratory system

(1) Provide an extensive area for gas exchange between inhaled air and the circulation;
(2) move air to and from the exchange surfaces of the lungs;
(3) protect the respiratory surfaces from dehydration, temperature changes, and other environmental variations and defend the respiratory system and other tissues from invasion by pathogens;
(4) produce sounds involved in speaking, singing, or nonverbal auditory communication;
(5) direct incoming air to the olfactory epithelium in support of olfaction;
(6) indirectly contribute to regulation of blood volume, blood pressure, and  pH.