Pseudociliated columnar epithelium is characterized by a single layer of epithelial cells, but appears to be multilayered, with scavenging, secretory, and moisturizing properties. Pseudociliated columnar epithelium is mainly found on the inner surface of the airway and is composed of spindle, cup, column, and cone-shaped cells. These cells vary in shape and size, and the location of the nucleus makes them appear to be multilayered. The pseudo-complex ciliated columnar epithelium secretes mucus, which maintains the normal function of the bronchial tubes and also has a moisturizing effect. In addition, the cilia of the epithelium oscillate to remove foreign bodies such as dust and bacteria.