Which of the following is a correct statement about mucus in the respiratory system?

The statement that mucus in the respiratory system traps and helps eliminate pathogens is correct because mucus plays a crucial role in the body's defense mechanisms. Mucus is a viscous substance secreted by the mucous membranes lining the respiratory tract. It serves several important functions, one of which is to trap dust, allergens, microorganisms, and other potential pathogens that enter the respiratory system.

By trapping these harmful particles, mucus prevents them from reaching the lower airways and the lungs. Additionally, the cilia—tiny hair-like structures on the surface of respiratory epithelial cells—work in tandem with mucus to move trapped particles upward toward the pharynx, where they can be swallowed or expelled. This mucociliary clearance is a vital aspect of the innate immune response, as it aids in keeping the respiratory system free from infection.

In contrast, mucus does not increase airflow; rather, it can sometimes reduce airflow if it accumulates excessively, blocking air pathways. It does not promote pathogen growth; instead, it creates a hostile environment for pathogens by trapping them and facilitating their removal. Lastly, mucus has a significant purpose in infection prevention through its role in trapping and eliminating pathogens, directly supporting the body's defense against respiratory infections.