video1.0<iframe src="https://www.loom.com/embed/d40314d22b8346cdb4ca84078a6b952b" frameborder="0" width="1662" height="1246" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>12461662Loomhttps://www.loom.com12461662https://cdn.loom.com/sessions/thumbnails/d40314d22b8346cdb4ca84078a6b952b-c8e7e2c455857386.gif3179.267This Loom explains adaptive immunity, focusing on how the immune system responds specifically to antigens. It contrasts cell-mediated immunity, where CD8 cytotoxic T cells target pathogens inside living cells via MHC class 1, with antibody-mediated immunity, where B cells produce antibodies against antigens in body fluids via MHC class 2 and helper CD4 T cells. It covers key adaptive features such as specificity, versatility, memory, and tolerance, and distinguishes active immunity (natural acquired vs artificially acquired through vaccination) from passive immunity (natural via placenta or breast milk, and artificially induced by antibody injection such as for rabies). It also outlines T cell and B cell activation steps, roles of antibodies and major immunoglobulin classes IgG, IgM, IgA, IgE, and IgD, and how primary versus secondary responses differ in timing (about one to two weeks to peak) and strength. Finally, it summarizes abnormal immune responses including autoimmune disease, immunodeficiency, and hypersensitivities like anaphylaxis, plus the impact of chronic stress through cortisol.