What does the respiratory system primarily do?

The primary function of the respiratory system is to bring air into the body, a process critical for obtaining oxygen and expelling carbon dioxide. This system includes structures such as the nose, trachea, lungs, and diaphragm, which work together to facilitate the exchange of gases. When we inhale, air travels through these structures and reaches the lungs, where oxygen is absorbed into the bloodstream, providing the necessary oxygen for cellular respiration. At the same time, carbon dioxide, a waste product of metabolism, is transferred from the blood to the lungs to be exhaled.

While other systems, like the circulatory system, manage blood flow, the primary role of the respiratory system is focused on gas exchange. This makes it essential not only for breathing but also for maintaining the body's overall metabolic needs. The other options, while they represent important functions of other bodily systems, do not capture the core purpose of the respiratory system itself.