Answer
The four types of stratified epithelium are stratified squamous epithelium, stratified cuboidal epithelium, stratified columnar epithelium, and transitional epithelium. Pseudostratified epithelium is sometimes included in this list , but pseudostratified epithelium does not really belong here-- it is only one layer deep.
Work Step by Step
1 Stratified squamous epithelium appears as many layers of cells. The cells nearer the surface look flatter and the uppermost layers are dead cells without nuclei. They may or may not be keratinized. The cells in basal layers may be cuboidal or columnar.
The main function of this tissue is to provide protection against physical injury for example, abrasion; it also opposes infection by pathogens.
Some areas where the keratinized variety is found are the epidermis, palms and soles of feet. The non-keratinized form appears on the tongue, oral mucosa, esophagus and vagina.
2. Stratified cuboidal epithelium. This type usually appears as two or more layers of cells:the surface cells may appear roundish or square.
This type of tissue produces germ cells (sperms and oocytes. The secretion of sweat and of ovarian hormones i are also functions of stratified cuboidal epithelium.
Some locations where this tissue may be found are follicles of ovaries, ducts of sweat glands and seminiferous tubules of testes
3. Stratified columnar epithelium is the third type of stratified epithelium: this is a rare type of tissue in which the surface layer of cells appear. columnar in shape. Some locations where tis type of tissue is found are pharynx, larynx, male urethra and anal canal.
4. Transitional epithelium. This type of tissue may appear as 2-3 layers or as 5-6 layers dependent on how much the tissue is stretched. Some cell of this tisue may appear with two nuclei per cell.
The functions are to allow stretching of some organs like the urinary bladder and to tissues from osmotic damage.
This tissue is found in the following sites: urinary tract, part of kidney; part of bladder; part of urethra, and in the umbilical cord..
Pseudo stratified epithelium the nuclei of the cells appear at different levels giving the appearance of multiple layers . But this tissue is only one layer deep-- all cells touch the basement membrane. Sites, trachea and upper respiratory tract . It functions to secrete mucus: also, the cilia of the ciliated cells move mucus upward.
