What is the primary function of the respiratory system?

The primary function of the respiratory system is to control the breathing of the body, which is crucial for the exchange of gases. This system is responsible for the intake of oxygen from the environment and the expulsion of carbon dioxide, a waste product of metabolism. The process of inhalation allows oxygen to enter the lungs, where it diffuses into the bloodstream for distribution to cells and tissues throughout the body. Conversely, during exhalation, carbon dioxide is expelled from the body, maintaining a balance of gases necessary for cellular function and overall homeostasis.

While filtering harmful substances is indeed a role of certain components of the respiratory system, such as the mucous membranes in the nasal passages, it is not its primary function. Similarly, regulating temperature can occur to some extent through the respiratory process, but it is secondary to the core purpose of gas exchange. Facilitating nutrient absorption is not a function of the respiratory system at all; this is primarily the role of the digestive system.