Final answer:
In emphysema, the walls of the alveoli are destroyed, leading to enlarged alveoli with decreased gas exchange surface area and loss of elastic recoil, causing trapped air after exhalation.
Step-by-step explanation:
In the pathophysiology of emphysema, several changes occur within the lungs due to smoking tobacco or other factors. Firstly, the walls of the alveoli are destroyed, leading to enlargement of the alveoli and decreased surface area for gas exchange. This results in less oxygen entering the blood and less carbon dioxide exiting. Secondly, there is a loss of elastic recoil in the lungs because the elastic fibers are damaged. This makes it difficult for the lungs to deflate completely, causing air to become trapped in the lungs after exhalation. Lastly, due to the damaged alveolar walls, the overall compliance of the lungs is increased, which means the lungs can expand more easily but are less effective at pushing air out. However, the increase in mucus production is more commonly associated with chronic bronchitis, another component of COPD, rather than emphysema specifically.