What are the common characteristics of epithelial tissue?

Epithelial tissues produce sheets of compact cells or roll into tubes. These cells are arranged in one or more layers and cover body surfaces and line body cavities. Another common characteristic is that they have a high regenerative potential, and damaged epithelial cells are able to be replaced through cell division. All epithelial cells are attached to the basement membrane, which provides structural support to epithelial tissue as well as separates it from connective tissue. Epithelial cells also have 2 different sides: the apical surface and basolateral surface. The apical surface lines the lumen and develops the interface between the extracellular space and tissue. The basolateral area includes the base and sides of the and contains the basolateral membrane. Another shared characteristic is that epithelial cells contain little to no extracellular matrix. This is because of the compact nature of the cells formed in continuous sheets, with little extracellular material between them. All epithelial cells are also avascular, and instead receive nutrients and oxygen via diffusion from connective tissue.