With the largest cytoplasmic volumes of all epithelia, these cells possess the organelle density and energy reserves to engage in the most complex and efficient secretory or absorptive functions. Ciliated types are found in small bronchioles of the respiratory tract and in the fallopian tubes of the female reproductive tract. In these locales, the cilia aid in the movement of mucous or reproductive cells . The unicellular gland or goblet cell, is a specialized columnar cell of mucous membranes that secretes mucous for protection. Cells are columnar but tall and thin.
All cells rest on the basement membrane.
The unique appearance of pseudostratified epithelia occurs because the tall, thin cells intertwine. Nuclei appear at various levels but there is no distinct layering. Pseudostratified epithelia are most prevalent in the upper or lower respiratory tract as ciliated types. Non-ciliated pseudostratified epithelium can be found in the ducts of larger glands or the male urethra but these may be transition zones between epithelial types. The cilia of respiratory pseudostratified epithelia beat in a rhythmic manner to propel mucous along the surfaces of cells.