Final answer:
Epithelial tissue is made of closely packed cells that cover body surfaces and line cavities, primarily for protection, absorption, and secretion, not for contraction or vascular purposes. It forms a basement membrane with the basal lamina and reticular lamina to support and connect tissues.
Step-by-step explanation:
The basic characteristics of epithelial tissue include the following: Epithelial tissue is made up of closely packed cells that form flat sheets which cover body surfaces, lines body cavities, and form certain glands. These cells are highly cellular with little to no extracellular material present between them. Epithelial tissue is not vascularized and does not contract; therefore, it is not specialized for contraction.
Instead, the epithelial tissue serves primarily as a covering or lining of body parts, protecting the body, and is also involved in absorption, transport, and secretion. Cells in epithelial tissue exhibit polarity with differences in structure and function between the apical surface (exposed) and the basal surface (underlying close to body structures). They are attached to each other and to the basal lamina, which in turn connects to the reticular lamina, forming a basement membrane that helps to hold everything together.