Functionally, the respiratory system can be divided into a conducting zone and a respiratory zone. The major organs of the respiratory system function primarily to provide oxygen to body tissues for cellular respiration, remove the waste product carbon dioxide, and help to maintain acid-base balance.

The conducting zone of the respiratory system includes the organs and structures not directly involved in gas exchange. Portions of the respiratory system are also used for non-vital functions, such as sensing odors, speech production, and for straining, such as during childbirth or coughing ( Figure 22.2 )

respiratory system — also used for non-vital functions, such as sensing odors, speech production, and for straining, such as during childbirth or coughing ( Figure 22.2 ). conducting zone — region of the respiratory system that includes the organs and structures that provide passageways for air and are not directly involved in gas exchange. respiratory zone — includes structures of the respiratory system that are directly involved in gas exchange. ala — (plural = alae) small, flaring structure of a nostril that forms the lateral side of the nares.

Be able to list the structures that make up the respiratory system; describe how the respiratory system processes oxygen and CO 2; compare and contrast the functions of upper respiratory tract with the lower respiratory tract.