The immunity system protects you from viruses and gets. The viruses, fugi, bacteria, protozoan, and parasites are called pathogens. The first line of defense against pathogens as the innate immunity, it includes the skin, body secretions, inflammation of body tissues, and phagocytes. The skin secretion is like a barrier that keeps pathogens out, body secretion, such as sweat protect us from pathogens with the enzymes located in it called lysozyme. The mucus in the body traps the pathogen and when we swallow the mucus it kills them with the stomach acid. Inflammation is when there is a danger tissue from injury or infections happen. The white blood cells release histamine that causes the blood vessel to dilate and create redness, the fluid leaks and destroys toxic agents.
The phagocytes are white blood cells that destroy pathogens by surrounding and engulfing them, there are three different kinds, macrophages, neurophils, and monocytes. The phagocyte macrophages is the first line of dense against pathogens in the tissue, it tries to engulf the pathogen, The next line of dense if neurophils if the macrophages doesn’t defeat them. Then finally there is the monocyte, which is an immature macrophage in the blood stream. It matures once they reach the infected site. Dead macrophages and body fluids is pus. If the pathogen is a virus the phagocytes can’t destroy hot cells. The interferon come in they are protecting cells from viruses.
Defending against a specific pathogen by gradually building up a resistance is called an acquired immunity. This happens in the lymphatic system. The lymphatic system is the system that is spread throughout your body, it made up of glands and vessels. There are two different immunities, one is the antibody and another Is the cellular. Antigens create the antibody immunity; they are proteins on the surface of pathogen, that help immune system recognizes an antigen and produces. The second one Is the cellular immunity, it uses killer or catatonic T cells, they are cells stored in the lymph nodes spleen, and tonsil.
There is a passive and active immunity, the passive immunity has two kinds. One is the natural when antibodies are transferred from the mother to the unborn baby, and second is the artificial passive immunity is when antibodies are injected into the body that come from another animal. The active transport also has two kinds, one is natural from when someone is exposed to antigens and the body produces antibodies and the second is artificial which is also known as a vaccine.
