PSEUDOSTRATIFIED EPITHELIA

Pseudostratified epithelia are thicker (taller) than simple epithelia. All the cells of the covering epithelium sit on the basal lamina, but the cells reach different heights: the basal cells are the smallest (they are pyramidal or cubic in shape), if there are intermediate cells they are elongated (spindle or tennis racket shaped) and the longest cells reach the surface. Due to the different cell sizes, their nuclei are arranged in multiple rows. For the resulting classification, it is most important to describe the shape of the superficial cells, i.e. the uppermost layer, as these cells are the most specialised and have the most typical morphology; it is also important to register the presence of structural differentiations on the apical cell surface (i.e. the presence of kinocilia or stereocilia). According to the shape of the superficial cells, the following types of cells are distinguished:

	- without cilia
- PSEUDOSTRATIFIED COLUMNAR EPITHELIUM	- with cilia
	- with stereocilia
- PSEUDOSTRATIFIED CUBOIDAL EPITHELIUM	(Transitional epithelium, urothelium)
Fig. 1. Scheme of pseudostratified epithelia. The description is given on the left of the figure; the basal lamina is shown by the black line under the epithelium.