ABSTRACT

The airway epithelial cell-mucociliary barrier protects us from infection by inhaled microbes, environmental irritants, and toxic materials. The constitutive epithelial cell defenses include secretion of antioxidants, antiproteases, and antimicrobial substances as well as the regulation of fluid balance. The nasal cavities are protected by squamous and ciliated epithelium. The proximal airways are lined by pseudostratified tall columnar epithelium composed of basal cells, mucus-producing secretory cells, and ciliated cells. The serous and mucous cells of the glands in the large airways are responsible for production of most of the mucous layer, which is essential for mucociliary clearance. In the bronchioles the epithelial lining turns into simple, cuboidal epithelium composed of ciliated cells and Clara cells. When the epithelium is damaged, Clara cells, basal cells, and secretory cells in the airways undergo

Disclaimer: The literature review described in this article has been supported by the United States Environmental Protection Agency. It has been subjected to Agency review and has been approved for publication. Approval does not necessarily reflect the views of the Agency and no official endorsement should be inferred. Mention of trade names and commercial products does not constitute endorsement or recommendation for use.