Simple columnar epithelial cells with cilia are numerous in the lining of the oviduct, where they are interspersed with secretory cells.

• Compare the appearance of the cilia in this epithelium with the striated border (microvilli) of absorptive epithelium on the last slide.
• Examine the ultrastructural views of the cilia and microvilli shown in cross section and in longitudinal section. Compare cilia (below) to the absorptive stereocilia at the apical surface of the pseudostratified columnar cells lining the epididymis (epididymis 1, and epididymis 2, and seen below).

• Cilia have a core of microtubules with associated motor proteins that allow them to beat, which in the oviduct facilitates movement of the ovum toward the uterus. In contrast, microvilli and stereocilia have a core of actin microfilaments and function to increase surface area for absorption.
• Learning about this is not just an academic exercise; rather, it has real clinical significance. Kartagener’s disease is an inherited disorder involving mutations in the gene for dynein or one of the many other proteins in cilia. All cilia in such individuals are immotile, leading to infertility and chronic respiratory disorders.
   

How about pseudostratified and stratified epithelium?