4. pseudostratified ciliated columnar epithelium Description: single layer of cells of differing heights but some don't reach the free surface Nuclei are seen at many different levels They contain goblet cells and cilia Function: secretion propulsion of mucus Locations: 1 the trachea most of the upper respiratory tract4. pseudostratified ciliated columnar epithelium Description: single layer of cells of differing heights, but some don't reach the free surface. Nuclei are seen at many different levels. They contain goblet cells and cilia. Function: secretion & propulsion of mucus Locations:l the trachea & most of the upper respiratory tract