What is the primary function of the respiratory system?

The primary function of the respiratory system is to supply oxygen (O2) to the body and eliminate carbon dioxide (CO2), which is a waste product of cellular metabolism. This process occurs primarily in the lungs, where oxygen is exchanged for carbon dioxide during respiration. Inhalation brings oxygen-rich air into the lungs, where it diffuses across the alveolar membranes into the bloodstream. At the same time, carbon dioxide from the blood is diffused back into the lungs and exhaled. This continuous gas exchange is crucial for maintaining the body's oxygen levels and preventing the build-up of carbon dioxide, which can lead to respiratory acidosis and other health issues.

While other systems in the body are responsible for functions such as temperature regulation, hormone production, and blood filtration, these are not primary roles of the respiratory system. The respiratory system's main responsibility is primarily centered on gas exchange, highlighting its vital importance to overall health and homeostasis.