increased food supplyEpithelial Tissue Function. Epithelial tissue covers the outside of the body and lines organs, vessels (blood and lymph), and cavities. Epithelial cells form the thin layer of cells known as the endothelium, which is continuous with the inner tissue lining of organs such as the brain, lungs, skin, and heart.
The cells in epithelial tissue are very closely packed together and joined with little space between them. With its tightly packed structure, we would expect epithelial tissue to serve some type of barrier and protective function and that is certainly the case. For example, the skin is composed of a layer of epithelial tissue (epidermis) that is supported by a layer of connective tissue. It protects the internal structures of the body from damage and dehydration.
Epithelial tissue also helps to protect against microorganisms. The skin is the body's first line of defense against bacteria, viruses, and other microbes.
