Final answer:
Clara cells help with airway clearance by secreting mucus to trap particles, using cilia to move mucus out of the respiratory system by the mucociliary escalator, and maintaining proper ion transport to keep mucus watery for effective movement.
Step-by-step explanation:
Clara cells, also known as club cells, contribute to the clearance of airways in the respiratory system in several ways. Firstly, they secrete mucus that traps particles and pathogens, which prevents them from reaching deeper parts of the lungs. Secondly, the mucus is then moved out of the respiratory system by the coordinated movements of cilia in a process known as the mucociliary escalator, effectively sweeping the mucus and trapped debris away from the lungs and toward the throat, where it can be expelled. Finally, Clara cells' role in maintaining the transport of ions like Cl- ensures that the mucus remains watery and not too viscous, allowing it to be moved effectively by the cilia.
In the absence of an efficient CFTR channel, such as in cystic fibrosis, Cl- ions are not transported effectively out of the cells, leading to thick and sticky mucus which the cilia cannot properly propel, trapping more pathogens and debris and increasing the risk of infections.