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.
Cross-section of pseudostratified columnar epithelium
Second cross-section
The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa.
Trachea Mainstem bronchus Lobar bronchus Segmental bronchus Bronchiole Alveolar duct Alveolus
3D still showing increased mucus.
3D still showing constricted airways.