In the respiratory system of man, diffusion of gases takes place in

Explanation

In the respiratory system of humans, the exchange of gases such as oxygen and carbon dioxide occurs. This process happens through a process called diffusion. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. One of the major structures involved in this process are the alveoli. The alveoli are tiny air sacs located at the end of the bronchioles in the lungs. They have a large surface area and thin walls which allows for the efficient exchange of gases between the lungs and the blood. Oxygen from the air we breathe diffuses across the walls of the alveoli into the bloodstream, while carbon dioxide from the bloodstream diffuses across the walls of the alveoli into the lungs to be exhaled. In contrast, the trachea, bronchi, and bronchioles are part of the airway that transports air into the lungs, but they do not participate in the actual exchange of gases. Therefore, the correct answer to this question is option C: Alveoli.