And in this lecture, we're going to discuss seven different functions of the skin. So let's begin by recalling some basic structure of the skin. So the outermost portion of the skin is the epidermis. And this portion contains four specialized cells that we're going to discuss in just a moment. We have carotene sites, we have melanocytes, we have Langerhon cells, and we also have Merkel cells. Now, the middle portion, the middle section of the skin, is our dermis.