Basic and Clinical Sciences (BCSE) Practice Exam

Pseudostratified ciliated columnar epithelium is characterized primarily by its unique structure and the presence of various specialized cells. One of its main features is the presence of cilia on the apical surface. The cilia play a vital role in moving mucus and trapped particles out of the airways, which is crucial for maintaining respiratory health and clearing pathogens.

Additionally, this type of epithelium typically contains goblet cells, which secrete mucus that helps trap debris and pathogens, enhancing the protective function of the epithelium. While microvilli can also be present in some epithelial types, the defining elements of pseudostratified ciliated columnar epithelium are its cilia and goblet cells.

Therefore, the option stating "All of the above" accurately encapsulates the main features of pseudostratified ciliated columnar epithelium since it includes the presence of cilia, goblet cells, and may include some microvilli, although the presence of cilia is the most prominent and recognizable characteristic. Understanding that these features work together to provide a protective and functional barrier in the respiratory tract is essential for recognizing the significance of this epithelial type in both health and disease.