The world's a dangerous place full of dangerous things. From flat earth earth to climate change, it's covered in them. And so are you. Pathogens cover all of our body. Millions of them. But don't you fret, our body puts up quite a fight. The immune system consists of two responses. Responses, not specific and specific. The first line of defense in the non-specific response consists of skin, mucus. What are you doing? I thought it would be an example or something. Stop. Oh, OK. Silia, saliva and stomach acid all keep me out those pesty pathogens. Now, when the first line of defense is broken, our body resorts to the second line of defense. Imagine component of this defense being phagotics. Now, there are two main types of phagocytes, neutrophils and macrophages, both of which participate in phagocytosis. Now, what is phagocytosis? I'll tell you, there are three major components. First of all, recognition. Oh, what's this pathogen doing here? Second part, being engulfing, but not eating. Third part, being the phagozomes using digestive enzymes to break down this pathogen. Outchers. Now, another component of the second line of defense is the inflammatory response. When something untweets your body that shouldn't be there, mass cells near your skin start to release histamine. Now, histamine will do multiple things. First of all, it will increase the redness of the area, and also swell up the area, and release heat. You might have experienced this when a mosquito bites you. Now, onto the third line of defense. It's just a big response. This is triggered by antigens on the surface of pathogens that pass the previous lines of defenses. When this happens, the immune system produces antibodies to attach onto the antigens. To later engulf and destroy the pathogen. In addition, there are cells called lymphocytes, which can be divided into B cells and T cells. With the binding of helper T cells onto B cells, the B cells become activated, rapidly growing, reducing plasma cells that release antibodies into the bloodstream, and memory B cells, which stores information about the pathogens to provide future immunity. This response is called fumeral immunity. The other component of the third line of defense is cell mediated death. I'm a killer T cell. Basically, I'm the assassin of the immune system. What I do is I search out for the cells that have already been infected with pathogens that cannot be saved. When I find them, eliminate them. Ape off those. So I hope you learned something about the immune system during this crazy cringe compilation. And I hope you get a 5 on the AP bio exam. Hasta la vista.