Which organ is primarily responsible for gas exchange in humans?

The lungs are primarily responsible for gas exchange in humans due to their specialized structure and function. Within the lungs, tiny air sacs called alveoli provide a large surface area for the exchange of oxygen and carbon dioxide with the blood. When we inhale, oxygen from the air enters the alveoli and diffuses through the alveolar walls into the bloodstream, where it binds to hemoglobin in red blood cells. Simultaneously, carbon dioxide, which is a waste product of metabolism, travels from the blood into the alveoli to be exhaled. This efficient exchange process is crucial for respiration, enabling the body to take in the oxygen necessary for cellular processes and eliminate carbon dioxide. The anatomical and functional design of the lungs, including their vast network of capillaries and extensive surface area, supports this critical role in gas exchange.