BCSE Practice Exam 2025 – Complete Study Resource

The predominant type of epithelial tissue in the breathing passages that require protection and secretion is ciliated pseudostratified columnar epithelium. This specialized epithelial tissue is characterized by its appearance, which gives the illusion of being stratified (layered) due to the varying cell heights, but every cell rests on the basal membrane, making it technically simple.

Ciliated pseudostratified columnar epithelium is equipped with cilia on its surface, which plays a crucial role in moving mucus upwards out of the respiratory tract. This helps to trap and expel inhaled particles and pathogens, thus providing protection to the underlying tissues. Additionally, the goblet cells interspersed within this epithelium secrete mucus, which adds another layer of defense by moistening the airway and trapping debris.

In contrast, simple squamous epithelium is more suited for areas where diffusion and filtration are necessary, such as the lining of blood vessels and alveoli, rather than for protection and secretion. Skeletal muscle is not an epithelial tissue and is involved in movement rather than secretory or protective functions. Cuboidal epithelium is typically found in glands and ducts, where it aids in secretion and absorption but is not predominantly