Pseudostratified ciliated columnar epithelia

This type of epithelium is found almost exclusively in the respiratory system and is also called respiratory epithelium.

• At first glance, pseudostratified ciliated columnar epithelium (seen in the image to the right) seems to be a stratified, rather than a simple epithelium because the nuclei appear to be located in multiple layers. However, this type of epithelium is indeed a simple epithelium because all of its cells contact the basement membrane.
• This epithelium provides protection, mucous secretions from goblet cells, and cilia-mediated movement of mucus and trapped particulate matter in the respiratory passages.
• Examine the cells lining the trachea in these specimens, trachea and thyroid, human trachea, and larynx in these trichrome  and H&E stained specimens. Note the appearance of this falsely stratified epithelium, as well as the cilia, goblet cells, and basement membrane.
   

Stratified squamous epithelium.