Page 657 - Atlas of Histology with Functional Correlations

FIGURE 17.1 ■ A section of the lung is illustrated in three dimensions and in
transverse section. Magnified versions of a bronchiole and a type II pneumocyte
(both circled here) are illustrated in Figures 17.2 and 17.3, respectively.

RESPIRATORY EPITHELIUM

Most of the respiratory structures are lined by pseudostratified ciliated columnar

epithelium. By examining this epithelium with both light and transmission
electron microscopes, several different cell types are recognized. Ciliated
columnar cells are the most abundant cells that extend the entire thickness of the
epithelium. The cilia sweep the surface of the epithelium and protect the lungs
by removing small inhaled particles.

Goblet cells are numerous in the more proximal airways and gradually
decrease in number toward the distal parts of the respiratory tube. These cells
contain and release mucus glycoproteins to form a protective layer on the
epithelial surface.

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