Mucus and ionocyte contributions to airway physiology and host defense

The human bronchial tree comprises a complex network of successively-branching airways that extend from the trachea to alveolar sacs, where vital gas exchange oxygenates the bloodstream. This expansive network encompasses a surface area similar in size to a badminton court and is exposed to pathogens and particulate matter with every breath. As such, the airways are far from sterile – but instead, are in a perpetual state of sterilization.