What is the main function of the respiratory system?

The main function of the respiratory system is gas exchange between the body and environment. This process primarily involves the inhalation of oxygen from the atmosphere and the exhalation of carbon dioxide, a waste product of metabolism. The respiratory system includes structures such as the lungs, trachea, and alveoli, where this exchange occurs at the cellular level. Oxygen is delivered to the blood and then transported throughout the body to be utilized by cells for energy production, while carbon dioxide is expelled from the body to maintain proper acid-base balance and prevent toxicity.

While other systems do play critical roles in the body—such as the digestive system in processing food, the circulatory system in moving blood, and the endocrine system in hormone regulation—the respiratory system's unique function is essential for sustaining life through the continuous supply of oxygen and the removal of carbon dioxide. This function highlights the importance of the respiratory system in maintaining overall health and homeostasis.