PAEA Surgery End Of Rotation (EOR) Practice Exam

What type of epithelium lines the appendix?

1. Squamous epithelium

2. Columnar epithelium

3. Cuboidal epithelium

4. Ciliated epithelium

The correct answer is: Columnar epithelium

The appendix is lined with columnar epithelium, which is adept at absorption and secretion, essential functions that occur within the gastrointestinal tract. This type of epithelium is characterized by its elongated cells that often include goblet cells, which secrete mucus. The presence of mucus is crucial in the appendix as it aids in protecting the epithelial surface and facilitating the movement of luminal contents. The structure of columnar epithelium supports the role of the appendix in immune function, particularly due to its significant lymphoid tissue. This type of epithelium is also well-suited for the microenvironment within the appendix, where it interacts with intestinal contents and the gut microbiota. Other types of epithelium—like squamous, cuboidal, or ciliated—do not align with the functional and structural characteristics of the appendix. Squamous epithelium is typically found in areas where protection against abrasion is needed. Cuboidal epithelium is more common in glandular tissue, and ciliated epithelium is usually associated with respiratory tracts rather than the digestive system. Therefore, the columnar epithelium is indeed the correct type that lines the appendix, matching its unique histological and physiological