In this video, we're going to introduce our map of the lesson on innate immunity, which is down below right here. And so we can go ahead and title the top of our map innate immunity. And so because this is a map of our lesson moving forward on innate immunity, this means that you can actually use this image as a map to help guide you as you move forward through the lesson. It's almost like a table of contents for our lesson moving forward. And so the way that we're going to explore this map as always is going to be by following the leftmost branches first. And so we'll talk about the first line of defense, including the physical, chemical barriers in the microbiome. Then, we'll start exploring the branches on the right, including the second line of defense, cells of immunity, the scanning systems, including cell communication, pattern recognition receptors, the complement system. And then, of course, we'll move on to the effectors, including phagocytosis, inflammation, fever, and the interferon response. And so we'll use this map as a guide, as a table of contents, and we'll cover the topics as you saw from left branch making your way over to the right branches.
And so one thing that's important to note about this map of the lesson on innate immunity is that innate immunity itself is really broken up into 2 lines of defense. We have the first line of innate defenses, and then we have the second line of innate defenses. And so, what you'll notice is that the first line of innate defenses are geared to prevent microbes from entering the tissues within the body. And so, taking a look at our innate immunity map, notice that the first line defenses are over here on the left, and notice that the second line defenses are all over here on the right. And so, taking a look at the first line defenses, notice once again, it includes physical and chemical barriers as well as the microbiome. Now the second line defenses are going to include cells of innate immunity that work to identify or ID, microbes that have invaded, as well as to eliminate microbes that have bypassed the first line of defense. And so, once again, notice the second line of defense is over here, this right branch of our map. But you'll notice that the second line of defense is really broken up into 2 further groups. We have the scanning systems, which could be 2a here, and then we have the innate effectors, which could be 2b. And so notice that the scanning systems are over here in our map, and the effectors are over here in our map in green. And so you can see how we are breaking down this innate immunity lesson.
And so the scanning systems are going to sense or scan the body in order to sense or detect signs of invading microbes, and they will do that by using sentinel cells. And so you can see sentinel cells kind of, goes hand in hand with this sense here. And so sentinel cells are cells that sense or detect signs of invading microbes. And so, what you'll see here is that these scanning systems include, cell communication, pattern recognition receptors, as well as the complement system. And once again, we'll talk a lot more details about this as we move forward in our course. Now the innate factors are going to be innate actions or innate responses that are geared to eliminate microbes that have been identified by the scanning systems. And so these innate effectors are going to include phagocytosis, inflammation, fever, and the interferon response, all of which we'll get to talk a lot more details about as we move in our course. Now another thing to note here is that the scanning systems can trigger the effectors. And so notice specifically the complement system is going to be able to trigger phagocytosis and inflammation. And so the complement system can promote phagocytosis and inflammation, and so we'll be able to talk more about these red arrows here, as we move forward in our course.
Now one thing to note is that the first line defenses somewhat resemble security walls that are protecting some facility. And so the security walls protecting a facility are going to prevent the entry of microbes, prevent microbe entry. And so the first line defenses of innate immunity somewhat resemble security walls, which is why we have the security wall image right next to it. Now the scanning systems somewhat resemble security cameras that are meant to detect signs of microbes and detect signs of damage caused by microbes. And so the scanning systems resemble security cameras. And so that's why we have the security cameras here. And then, of course, last but not least, the innate effector actions, resemble security soldiers because they are going to eliminate invaders, and so that's why we have the security soldiers here next to the effectors. And so this here is helpful to keep in mind as we move forward throughout our lesson. And once again, you want to be able to use this map, and refer back to this map as we move forward through our lesson so that you don't get lost and you know exactly where we are going, within our lesson. And so once again, we're following this map by following the leftmost branches first. So we'll talk about the first line defenses first, and then we'll move on to talk about the second line defenses. And so this here concludes our brief introduction to our map of the lesson on innate immunity, and so I'll see you all in our next video.
