BCSE Practice Exam 2025 – Complete Study Resource

The bronchioles are lined with ciliated columnar epithelium, which plays a significant role in the respiratory system. This type of epithelium is characterized by cells that are taller than they are wide, resembling columns, and they have hair-like projections called cilia on their surface. The presence of cilia is crucial because they help propel mucus and trapped particles out of the airways, aiding in the maintenance of clear and unobstructed air passages.

Ciliated columnar epithelium is especially important in the bronchioles because it helps facilitate the removal of debris and pathogens, contributing to the overall function of the lower respiratory tract. As the airways progress from the trachea into the bronchi, and finally into smaller bronchioles, the epithelial cells transition in size and function, with ciliated columnar epithelium being predominant in larger airways and present in varying forms as the bronchioles become more distal.

This specific functionality and structure of ciliated columnar epithelium make it well-suited for its location in the bronchioles, ensuring efficient cleaning of inhaled air before it reaches the alveoli, where gas exchange occurs.