Which organ is primarily responsible for gas exchange in the respiratory system?

The lungs are primarily responsible for gas exchange in the respiratory system. They contain alveoli, which are tiny air sacs that provide a large surface area for oxygen to diffuse into the blood and carbon dioxide to diffuse out of the blood. This exchange occurs as air is inhaled into the lungs, where oxygen is absorbed and carbon dioxide is expelled during exhalation. The structure of the lungs, along with their extensive network of capillaries, is specifically designed to facilitate this crucial process, making them central to the respiratory function.

Other organs, such as the heart, trachea, and diaphragm, play supporting roles in respiration. The heart circulates the oxygenated blood throughout the body, the trachea serves as the airway leading to the lungs, and the diaphragm helps in the mechanics of breathing by contracting to allow air to enter the lungs. However, the actual gas exchange occurs within the lungs, confirming their primary role in this vital respiratory function.