Final answer:
Smoking causes damage to the lungs' alveoli, impairing gas exchange, reducing lung elasticity, and leading to obstructive diseases like COPD and emphysema as well as increasing infection risk.
Step-by-step explanation:
When a smoker develops damage to alveoli, the essential process of gas exchange is impaired. The alveoli are small sacs within the lungs where oxygen is transferred into the blood and carbon dioxide is removed. Chronic inhalation of smoke leads to substances like tar and chemical compounds such as carbon monoxide and cyanide accumulating in the lungs. These substances destroy the elasticity of alveoli, leading to diseases like chronic obstructive pulmonary disease (COPD) and emphysema where lung tissue breaks down. This damage hampers the lungs' ability to fully exhale air, and the reduced surface area of alveoli decreases overall oxygen intake and carbon dioxide expulsion. Consequently, the smoker experiences shortness of breath and reduced oxygen supply to tissues, with a higher susceptibility to lung infections due to compromised immune defenses.
Moreover, smoking paralyzes and destroys the cilia, which are responsible for removing mucus and debris from the lungs. With the cilia incapacitated, mucus builds up, and infections become more frequent since the lungs cannot effectively clear out pathogens. Individuals with damaged alveoli due to smoking are more likely to suffer from respiratory ailments and have a persistent cough as the body attempts to expel trapped particulate matter.