Bronchial glands and mucus secretion

Bronchial glands and mucus secretion refer to the integrated physiological process of producing and transporting the protective fluid layer that lines the respiratory tract. This system is primarily composed of submucosal glands and surface goblet cells that secrete mucins, such as MUC5AC and MUC5B, which polymerize to form a viscoelastic gel [1]. The primary biological role of this secretion is mucociliary clearance, where mucus traps inhaled pathogens and debris to be transported out of the lungs by ciliary beating [2]. In chronic inflammatory airway diseases like COPD and asthma, the system becomes dysregulated, resulting in gland hypertrophy and mucus hypersecretion that contributes to airway obstruction and exacerbations [3]. Therapeutic strategies target this system by either reducing the volume of secretion via anticholinergic blockade of muscarinic receptors or by using mucolytics and expectorants to facilitate the clearance of existing secretions [4].

Other names

Airway mucus secretionBronchial submucosal glandsMucus hypersecretionAirway surface liquid

Pharmacological agents modulate this system through several pathways: muscarinic M3 receptor antagonists (e.g., ipratropium) inhibit parasympathetic stimulation of submucosal glands to reduce secretion volume; mucolytics (e.g., acetylcysteine) break disulfide bonds within mucin glycoproteins to reduce gel viscosity; and CFTR modulators (in cystic fibrosis) improve ion and water transport to hydrate the mucus layer [1, 2, 4].