Epithelial tissue or epithelium forms the skin’s outer cover that also lines the cavity of the body. It forms the lining of tracts that are respiratory, digestive, reproductive and excretory. They perform different functions including absorption, secretion, sensation, protection and secretion.
Structure of epithelial tissue
- Epithelial tissue is formed from a continuous, tightly packed layer of cells.
- One epithelial tissue surface is either transparent to the external atmosphere or the fluid in the body.
- A membrane which is made up of fibers and polysaccharides secreted by epithelial cells binds the other surface to the tissue.
Functions of epithelial tissue
They perform different functions including
- Protection and
Types of epithelial tissue
There are three categories of epithelial cells, that shape and function are different.
- Squamous which are small, flat cells
- Cuboidal that are short cylindrical cells that look like hexagonal in cross-section
- Columnar long or column-like cylindrical cells, containing nuclei at the base.