mucociliary

The mucociliary system, or mucociliary clearance, refers to the coordinated action of mucus production and ciliary motility in the airway epithelium that removes inhaled particles and pathogens from the respiratory tract.

It comprises goblet cells and submucosal glands that secrete mucus, which forms a gel layer over a periciliary liquid layer; ciliated respiratory epithelial cells propel the mucus toward the pharynx in a metachronous beat.

Mucus composition and rheology are critical; mucus traps particles; ciliary beat frequency and coordinated timing ensure clearance. Hydration and ion transport maintain mucus rheology; dehydration or reduced chloride transport impairs clearance.

Dysfunction contributes to disease: primary ciliary dyskinesia (cilia immotility or dyskinesia) causing chronic infections; cystic fibrosis leads to dehydrated, viscoelastic mucus; smoking and pollutants reduce ciliary beat and mucus transport; chronic bronchitis.

Clinical aspects and management: assessment methods include imaging and nasal nitric oxide and saccharin test; management strategies emphasize airway clearance techniques, humidification, hypertonic saline inhalation, and mucolytics, along with bronchodilators when appropriate. Treating the underlying disease and measures such as vaccination can support respiratory protection.