– A single row of tall, closely packed cells oriented in a row is a simple columnar epithelium. These cells can be located in places with a high secretory function (such as the stomach wall) or in absorptive areas (such as the small intestines).  Cellular extensions are present in them (e.g., microvilli in the small intestine, or the cilia found almost exclusively in the female reproductive tract).

– Simple cuboidal epithelium is made up of cells that are as tall as they are wide in a single layer. Secretion and absorption are two fundamental functions of the simple cuboidal epithelium. The small collecting ducts of the kidneys, pancreas, and salivary glands all have this epithelial type.

– When examined in cross section, they are simple columnar epithelial cells with nuclei that appear at varying heights, creating the false (thus pseudo) appearance that the epithelium is stratified.

Cilia are fine hair-like extensions of the apical (luminal) membrane found in pseudostratified epithelium. The epithelium is described as ciliated pseudostratified epithelium in this scenario. Ciliated epithelium can be found in the airways (nose, bronchi), as well as in the female uterus and fallopian tubes, where the cilia transport the ovum to the uterus.

Source:
Lumen (n.d.). Epithelial tissue. Retrieved from https://courses.lumenlearning.com/boundless-ap/chapter/epithelial-tissue/