Which structure increases airway resistance in chronic obstructive pulmonary disease?

In chronic obstructive pulmonary disease (COPD), lumen narrowing is a critical factor that increases airway resistance. This narrowing can result from inflammation, bronchial smooth muscle contraction, mucus hypersecretion, and structural changes in the airway walls, leading to obstructed airflow.

The narrowing of the airways means that the space through which air can travel becomes smaller, thereby increasing resistance during breathing, particularly during exhalation. This is significant because COPD is characterized by difficulty in expelling air from the lungs, a condition that is exacerbated by any narrowing of the airway lumen.

In contrast, airway dilation would decrease resistance, while an increase in elastic quality and a decrease in airway volume do not directly contribute to the main issue of resistance in the context of COPD. Thus, lumen narrowing is the key mechanism behind the increased airway resistance seen in this disease.