Which system regulates the exchange of gases in the body?

The respiratory system is responsible for regulating the exchange of gases in the body, specifically oxygen and carbon dioxide. This system includes key structures such as the lungs, trachea, and diaphragm, which work together to facilitate inhalation (bringing oxygen into the body) and exhalation (removing carbon dioxide).

During breathing, oxygen from the air enters the alveoli in the lungs, where it diffuses into the bloodstream. Simultaneously, carbon dioxide, a waste product of cellular metabolism, is transferred from the blood into the alveoli to be exhaled. This critical process not only supplies the body with the oxygen necessary for cellular respiration but also helps to maintain the pH balance of the blood by regulating carbon dioxide levels.

Other systems, such as the nervous or endocrine systems, do play supportive roles in controlling and regulating respiratory rates through signals and hormones, but they do not directly facilitate the gas exchange process itself. The muscular system assists in the mechanics of breathing, such as during contraction and relaxation of diaphragm and intercostal muscles, but it does not include the structures that enable gas exchange. Thus, the respiratory system is uniquely dedicated to this vital function, making it the correct choice for this question.