The simple columnar epithelium is characterized by presenting a single layer of cylindrical cells, with the basal and oval nucleus. This type of epithelium is found throughout the entire digestive epithelium, mainly on surfaces with high absorption power such as the walls of the small intestine, but they are also found on secretory surfaces such as the stomach walls, in the gallbladder, in some sections of the collecting tubes of the kidney, in the uterine tube (where it is ciliated) and in the uterus itself.
Squamous Stratified Epithelium is made up of basal cells that are cuboidal or columnar and metabolically active and superficial cells are flattened (squamous). Its function is to protect the underlying tissues in areas subject to nuclei abrasion, this epithelium (not keratinized) forms the wet surfaces of the basal esophagus, oral cavity and vagina. The oropharynx and the pharynx itself are lined by a stratified squamous epithelium as well.
