We have connective tissue, muscle tissue, nervous tissue, and we also have a tissue that is found in our digestive system and exciratory system known as the epithelial tissue or simply the epithelium. Now, epithelium consists of specialized types of cells known as the epithelial cells cells. And these cells come in different forms and different shapes as we'll see in just a moment. Now, first, let's define what the function and the purpose of the epithelial tissue is. So the epithelial tissue has three important functions. Firstly, it functions in protection.