Ciliary beat frequency in human bronchi and bronchioles

Study objective: This study aimed to determine the differences ciliary beat frequencies of respiratory ciliated cells from peripheral bronchioles and from proximal bronchi in humans. Design: Measurements were made from resected lungs. Ciliated cells were harvested by brushing the mucosa of each site immediately after surgery. Brushings with a cytology brush were performed on normal areas of the resected cartilaginous bronchus for proximal samplings and through a peripheral bronchiole close to the visceral pleura for peripheral samplings. For each site, at least 12 different measurements were made at 22 degrees C using an image analysis system. Results: A highly significant difference between proximal bronchi (mean, 7.1 Hz; SD, 1.29) and peripheral bronchioles (mean, 4.6 Hz; SD, 1.39) (p < 0.001) was found. Conclusion: Thus, cilia from peripheral bronchioles beat at a 35% lower beat frequency than cilia from proximal bronchi.