Question

Explain epithelial tissues on the basis of cell shape and function.

Answer 1

There are three principal cell shapes associated with epithelial cells: squamous epithelium, cuboidal epithelium, and columnar epithelium. There are three ways of describing the layering of epithelium: simple, stratified, and pseudostratified.Pseudostratified epithelium possesses fine hair-like extensions called cilia and unicellular glands called goblet cells which secrete mucous. This epithelium is described as "ciliated" pseudostratified epithelium. Stratified epithelium differs from simple epithelium in that it is multilayered. It is therefore found where body linings have to withstand mechanical or chemical insult. In keratinized epithelia, the most apical layers (exterior) of cells are dead and and contain a tough, resistant protein called keratin. An example of this specialization is found in the mammalian skin which makes the epithelium waterproof.Transitional epithelia are found in tissues such as the urinary bladder where there is a change in the shape of the cell due to stretching