Cilia in epithelial tissues function to move mucus, debris, or gametes. They are typically found in which locations?

• A. Digestive gland ducts
• B. Skin surface and hair follicles
• C. Cardiac muscle and nerves
• D. Respiratory tract and fallopian tubes

Answer: (D)

Motile cilia on epithelial cells beat in coordinated waves to propel substances across the surface. This movement is especially important in areas where mucus or fluids need to be moved out of the way or toward a specific route. In the respiratory tract, ciliated epithelium lines the airways and helps move mucus and trapped particles upward to the throat for removal, keeping the lungs clear. In the fallopian tubes, ciliated epithelium aids in transporting the ovum toward the uterus, assisting gamete movement. These locations exemplify where ciliated epithelia perform their role of moving mucus, debris, or gametes along the epithelium.

Other options don’t fit because digestive gland ducts are not typically lined by ciliated epithelium, the skin surface lacks cilia, and cardiac muscle and nerves are not epithelial tissues and don’t feature ciliated cells.