Which pulmonary defense mechanism propels a mucous blanket and entraps particles toward the oropharynx where they are swallowed or expectorated?
A) Nasal hairs and turbinates
B) Alveolar macrophages
C) Cilia
D) Irritant receptors on nares

Question

Quizplus · Accepted Answer

Cilia are hair-like projections on the surface of the respiratory epithelium that beat rhythmically in a coordinated manner to propel the mucous blanket and any entrapped particles towards the oropharynx, where they can be swallowed or coughed up. Nasal hairs and turbinates filter large particles and irritants from inspired air, but they do not propel mucous. Alveolar macrophages are phagocytic cells that ingest and destroy foreign particles that reach the alveoli, but they are not involved in mucociliary clearance. Irritant receptors on nares are specialized nerve endings that trigger reflexes to sneeze or cough in response to irritants, but they do not actively participate in particle clearance from the airways.

Which Pulmonary Defense Mechanism Propels a Mucous Blanket and Entraps