Introduction to Immunity

in this video, we're going to begin our introduction to immunity. And so when our bodies are attacked by foreign microbes, we actually have various defense mechanisms to help protect us from those attacking microbes. And so we collectively refer to these defense mechanisms as our immunity. And so immunity can be defined as our ability to eliminate disease causing microbes from our bodies and to help protect our bodies against environmental agents such as pollen. For example. Now susceptibility on the other hand refers to the lack of immunity towards some kind of agent. Now our immune systems are really broken up into two major groups and so really there are two general types of immunity. The first is going to be innate immunity and the second is going to be adaptive immunity. Now in eight immunity is also sometimes referred to as non specific immunity. And so innate implies that this is going to provide routine protection that is present at birth. And that's really what this innate term refers to that the fact that we are born with these innate protective immune responses. Now, the reason that it is also referred to as non specific immunity is because this type of immunity protects us against a very broad range of many different types of pathogens. Now the second major group of our immune system is going to be adaptive immunity and adaptive immunity is also sometimes referred to as specific immunity. And so the adaptive part of adaptive immunity implies that it includes components that are capable of adapting or changing over time. And that means that as we expose ourselves to new environments and different types of environmental agents, our adaptive immune responses are capable of changing and adapting and evolving to become better at protecting us over time. And uh it is also referred to as specific immunity because this type of immunity will provide us with protection against very specific types of pathogens. Now as we move forward in our course, we're going to talk a lot more details about both innate or non specific immunity first and then we'll talk a lot more details about adaptive or specific immunity much later. However, it is important to know that although generally innate and adaptive immunity are taught separately um that some parts of innate immunity will complement some parts of adaptive immunity and vice versa. And so there is a little bit of cross talk between innate immune responses and adaptive immune responses. And as we move forward in our course, that's important to keep in mind. And it is also going to be something that will try to make connections between the two as we move forward in our course. And so if we take a look at our image down below, notice that the left hand side over here is focused specifically on innate immunity which once again, recall is also referred to as non specific immunity that provides routine protection that is present at birth against a broad range of many different types of pathogens and innate immunity includes things such as physical barriers such as our skin and mucous membranes. It also includes chemical defenses such as antimicrobials, acids, bases and things of that nature. And we'll get to talk a lot more about these chemical defenses as we move forward in our course. Uh And it also includes a collection of several different innate immune cells which once again we'll get to talk a lot more details about them as we move forward in our course. Now over here, the right side of the image is focused specifically on adaptive immunity. And once again, adaptive immunity is also referred to as specific immunity and it includes components that adapt or change over time in response to changing environments. And also exposure to different types of pathogens. And adaptive or specific immunity provides protection against very specific types of pathogens. Uh And adaptive immunity includes antibodies which are these y shaped proteins that are capable of binding to foreign molecules and generating some kind of immune response. And we'll get to talk a lot more about antibodies as we move forward in our course. And adaptive immunity also includes adaptive immune cells such as for example, B cells and T cells. And again, we'll get to talk a lot more about the adaptive immune cells as we move forward in our course as well. But for now this year concludes our brief introduction to immunity and how our immune systems are broken up into two major categories innate immunity and adaptive immunity. And again, there is sometimes going to be some parts of each type of immunity that are going to complement each other and they work together in some cases. And so uh we will get to learn a lot more as we move forward, so I'll see you all in our next video.

in this video, we're going to briefly discuss antigens and antibodies. And so antigens and antibodies. But specifically antibodies play a significant role in adaptive immunity or specific immunity. Now, the term anti gin really is a broad term that refers to any toxin or foreign substance such as a foreign microbe that induces an antibody immune response. And so antibodies are going to be y shaped proteins that recognize and bind to specific antigens. And so if we take a look at our image over here on the left hand side, notice that we're showing you this Y shaped protein right here and this Y shaped protein is indeed going to be our antibody. And notice that the antibody has these two antigen binding sites here that are in green, allowing the antibody to bind to an antigen. And notice here in red we have our antigen. Now, antigens and antibodies are capable of triggering an immune response and the immune response can be different. And we'll get to talk about many of the different types of immune responses that anybody's are capable of generating as we move forward in our course later in our course and different video. But for now, just so that you can get an understanding uh notice that in this image we're showing you a pathogen which is down below some kind of disease causing agent, a microbe for example. And this microbe on its surface has these specific antigens on its surface and our bodies are capable of generating y shaped proteins as you see here that are capable of binding to the androgen and uh when the antibody binds to the androgen, it's able to trigger some kind of immune response. For example, it can allow a host immune cells such as this one right here to target the pathogen and eliminate the pathogen. And so notice that we're showing you the immune cell is attacking the pathogen through the release of specific chemicals here, and that will kill the pathogen and eliminate the pathogen. And so you can see here how antibodies can play a very important role in immunity. And we'll get to talk a lot more about antibodies later in our course when we talk a lot more about adaptive immunity. But for now this year concludes our brief introduction to antigens and antibodies and we'll be able to talk a lot more about immunity as we move forward in our course. So I'll see you all in our next video.