1) Provide large area for gas exchange between air & circulating blood.
2) Moving air to & from the gas-exchange surfaces of the lungs.
3) Protecting respiratory surfaces from dehydration & temperature changes & defending against invading pathogens.
4) Producing sounds that permit speech, singing, & nonverbal auditory communication.
5) Providing olfactory sensations to the CNS for the sense of smell.
Functions of the Respiratory System