Epithelial tissues cover the surface of the body, it consists of tight cells densely packed. Epithelial tissue is waterproof and aids in protecting the body from harmful external factors. There are many different types of epithelial tissue cells, squamous, cuboidal, and columnar, they all have different functions when it comes to the protection of the internal body. Epithelial tissues are considered avascular because there are no blood vessels on the underlying tissue. The image shows a picture of my hand, my hand is a very good example of epithelial tissue because it is completely engulfed by epithelial tissue!