Final answer:
The respiratory system's functions include the exchange of oxygen and carbon dioxide, providing an air passage, the detection of odors, and sound production. Regulation of Na+ plasma levels, however, is not a function of the respiratory system.
Step-by-step explanation:
The functions of the respiratory system include several crucial processes needed for the maintenance of life. The main functions are:
- Exchange of O2 and CO2: The primary purpose of the respiratory system is to deliver oxygen to the cells of the body’s tissues and to remove carbon dioxide, a waste product of cellular respiration. This gas exchange occurs in the alveoli of the lungs.
- Allows air passage: The nasal cavity, trachea, and lungs work together to provide a passageway for air to move into and out of the lungs.
- Detection of odors: The nasal passages contain the olfactory receptors, which are responsible for the sense of smell.
- Sound production: Parts of the respiratory system, particularly the larynx, work in conjunction with the vocal cords to produce sound.
The control of Na+ plasma levels is not a function of the respiratory system; it is mainly regulated by the kidneys.