In this video, we're going to continue to talk about the epidermis as we focus in on the layers of the epidermis. And so the epidermis or the outermost portion of our skin is actually composed of several distinct layers of cells. And so notice that down below, on the left hand side, we're showing you the diagram of the integumentary system. And once again, we're only coloring the epidermis or the outermost portion of our skin. And notice that zooming into the epidermis, we can clearly see that there are several distinct layers of cells. And so it's important to note that the term stratum is a term that means layer in Latin. And the plural form of this word is actually strad up, which means layers. Now notice that down below, we have listed and numbered the layers of the epidermis. And notice that the numbering is actually in order from the deepest layer of the epidermis, which is furthest away from the external environment to the most superficial layer of the epidermis, which is immediately adjacent to the external environment. And so the reason that we have these layers numbered in this particular order from deepest to most superficial is because that is the order that we are going to be covering these layers moving forward in our lesson and also numbering the layers in this particular order from deepest to most superficial is going to help us better understand the development of the cells in these layers over time. Now, the layers of the epidermis, in order from deepest to most superficial are the stratum bali, the stratum spinosa, the stratum granulosa, the stratum lucidum and the stratum corneum. Now, it's important to note that the number of layers of the epidermis can actually vary depending on the type of skin. And so there is what is known as thin skin and there's also what's known as thick skin. And in our next lesson video, we're going to distinguish further between thin skin and thick skin. But what's really important to note here in this video is that the stratum lucidum has an asterisk next to it. And this is because the stratum lucidum is a layer of the epidermis that is only found in thick skin and it is not found in thin skin. And so that's something that's very important to note. Now, we do have a memory tool to help you remember the layers of the epidermis in order from the deepest layer of the epidermis to the most superficial layer of the epidermis. And that memory tool is beautiful skin glow like crystals where the first letter of each of these words is a symbol to represent the first letter of each of the layers of the epidermis in order from the deepest layer to the most superficial layer. And so moving forward in our course, we're going to talk more details about each of these layers of the epidermis. And we'll also get to distinguish between thin skin and thick skin. So I'll see you all in our next video.
