Which epithelium has nonciliated and ciliated varieties, with nonciliated lining most of the digestive tract and ciliated lining small bronchi and uterine tubes?

• A. Simple columnar epithelium
• B. Pseudostratified columnar epithelium
• C. Transitional epithelium
• D. Stratified squamous epithelium

Answer: (A)

Epithelia that line surfaces can be tailored for different jobs. Simple columnar epithelium is a single layer of tall cells. In the digestive tract, this layer is usually nonciliated and specialized for absorption and secretion; microvilli on the apical surface increase surface area for nutrient uptake, and goblet cells secrete mucus to protect and lubricate the lining. In contrast, the same cell type can be ciliated in locations where movement is needed—such as the uterine tubes, where cilia help sweep the egg toward the uterus, and in parts of the small bronchi where cilia help move mucus and trapped debris out of the airways. This combination of nonciliated and ciliated forms within the same cell type is why simple columnar epithelium best fits the description.