page_title: Respiratory epithelium
section_title: Structure
hierarchical_section_title: Respiratory epithelium / Structure
caption_attribution_description: English: Pseudostratified epithelium, highlighting the pseudostratified epithelial cells, goblets cells, then underlying connective tissue
context_page_description: Respiratory epithelium, or airway epithelium, is a type of ciliated columnar epithelium found lining most of the respiratory tract as respiratory mucosa, where it serves to moisten and protect the airways. It is not present in the vocal cords of the larynx, or the oropharynx and laryngopharynx, where instead the epithelium is stratified squamous. It also functions as a barrier to potential pathogens and foreign particles, preventing infection and tissue injury by the secretion of mucus and the action of mucociliary clearance.
context_section_description: The respiratory epithelium lining the upper respiratory airways is classified as ciliated pseudostratified columnar epithelium. This designation is due to the arrangement of the multiple cell types composing the respiratory epithelium. While all cells make contact with the basement membrane and are, therefore, a single layer of cells, the nuclei are not aligned in the same plane. Hence, it appears as though several layers of cells are present and the epithelium is called pseudostratified (falsely layered). The respiratory mucosa transitions to simple cuboidal epithelium and finally to simple squamous epithelium in the alveolar ducts and alveoli.
caption: Pseudostratified columnar epithelium, animated image highlights the epithelial cells, goblet cells, then underlying connective tissue