The immune system provides immunity against …show more content…
They are found in a number of different systems including the integumentary, respiratory, digestive, and uro-genital. Skin not only acts as physical barrier but sweat is incredible acidic and salty which aren’t ideal conditions for many microbes. Our tears are also a barrier that washes away any microbes that reach our eyes. In the respiratory system the mucus found in our noses and lining our upper respiratory tract captures microbes and tries to remove them typically through cilia that moves the trapped microbe up our throat. The hair in our noses traps microbes found in the air we breathe. The digestive system also has barriers put in place like stomach acid which has a pH of 2 and saliva which contains lysosomes that destroy microbes. Vomit and the passing of feces are methods of physically expelling any microorganisms. Urine gets rid of any foreign body found in the …show more content…
The first is known as the humoral response where antibodies are responsible for the defeat of the pathogen. It begins when a macrophage engulfs a cell with an antigen on its surface. The macrophage then has MHC II on its surface which bind to an inactive helper T cell. The helper T cell can then recognize whether the engulfed cell is foreign or not. Once it realized there is a foreign body the T cell begins changing and begins creating more helper T cells. Inactive B cells that have the same antigen on its surface as the one found on MHC II binds to a helper T and the chemicals secreted by the helper T result in the activation of the B cell. When B cells found in blood and lymph recognize a pathogen through its antigens it begins the production of plasma and memory cells. Memory cells will create an immunological memory for that specific antigen so the response time is shorter the second time that pathogen invades. Meanwhile plasma cells create Y-shaped proteins known as antibodies. These antibodies form an antigen-antibody complex that eventually kills off the pathogen. It begins with antibodies surrounding the pathogen and binding to the antigen epitopes so the pathogen is essentially useless. Agglutination typically will occur, especially with bacteria, creating a clump of antibodies and pathogens. This makes it much easier for macrophages to find for phagocytosis. Then using compliment proteins, the antibodies