Like every other cell, they are surrounded by cellular membranes. The cells that are present in these tissues show all the characteristics of animal cells. These tissues protect and extend friction or abrasion in the number of layers of cells. These tissues are thin in appearance and often consist of cilia or microvilli and composed of one layer of cells.By depending on functions is a specific location, there are different types of epithelial tissues. In these cases, it is often necessary to use certain biochemical markers to make a positive identification. Cell junctions are the contact points between plasma membrane and tissue cells. They are free from nerves and blood vessels; and they are supported by connective tissue, known as Basement Membrane.The epithelial tissues perform many functions including protection from abrasion, radiation damage, chemical stress and invasion by pathogens. These cells may be cuboidal, squamous, or columnar.Simple squamous epithelium lies in the alveoli of the lungs and important for gases exchanging between lungs and blood. Mostly, the skin of all mammals consists layer of thick keratinized dead epithelial cell. One layer of cells has an apical surface exposed to the lumen of organs or to the external environment. For the fungal structure of the same name, see

The intermediate filament proteins in the Cancers originating from the epithelium are classified as Human cheek cells (Nonkeratinized stratified squamous epithelium) 500x The cells comprising an epithelial layer are linked via semi-permeable, tight junctions; hence, this tissue provides a barrier between the external environment and the organ it covers. But this is not always the case, such as when the cells are derived from a tumor. Simple cuboidal epithelium lines the lumen of collecting ducts in the kidney and found in thyroid around follicles that extract thyroid hormones. The basement membrane is important for transport nutrients, clearance of waste materials and transmission of neural signals. The cells which make epithelial are usually closely bound together by special structure, known as Tight Junction. Glandular tissue is the type of epithelium that forms the The slide shows at (1) an epithelial cell infected by Epithelium grown in culture can be identified by examining its morphological characteristics. Simple squamous epithelium, because of the thinness of the cell, is present where rapid passage of chemical compounds is observed.
Epithelial tissues are nearly completely avascular.

The esophagus exposed a wide range of different textures, pH levels, and chemical compositions, it also has a protective epithelium.In contrast, the epithelial tissues can also work for absorption, secretion, and movement of substances.

Simple columnar epithelia lie in the female reproductive system and in the digestive tract.

It's good to have the basement membrane on your side, because if there wasn't any, you wouldn't have much epithelial tissue. In addition to this protective function, epithelial tissue may also be specialized to function in secretion, excretion and absorption. Epithelium (/ ˌ ɛ p ɪ ˈ θ iː l i ə m /) is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue.Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs.

Epithelial cells are the building blocks of epithelial tissue. Epithelial cells tend to cluster together, and have a "characteristic tight pavement-like appearance". Simple columnar epithelia lie in the female reproductive system and in the digestive tract. Animal cells do not have a cell wall and this is what gives them flexibility.