So when the innate immune system carries out inflammation it basically calls upon macrophages. So this is our macrophage. Now, what the macrophage does is it engulfs and breaks down these different types of pathogens. And what it also does is it takes the antigens of these pathogens and places the antigens on the surface on the membrane of the macrophage. The question is what for? Well, because as it turns out the B lymphocytes as well as the T lymphocytes as we'll see in just a moment contain these receptors on the membrane of the lymphocytes.