The Immune System

        The tolerant carcass is a group of cells, molecules, and tissues that help typify the body against diseases and other harmful occupyrs. The resistive system provides justification against a build of potentially damaging substances that can invade the body. These substances include disease-causing organisms, such as bacteria, fungi, parasites, and viruses. The bodys ability to resist these invaders is called immunity. A key have of the repellent system is its ability to abrogate foreign invaders while passing the bodys own healthy tissues alone. Sometimes, however, the immune system attacks and damages these healthy tissues. This reaction is called an autoimmune revert or autoimmunity.         The immune system is composed of many give out that work together to fight infections when pathogens or poisons invade the merciful body. Pathogens atomic number 18 disease- causing organisms such as bacteria and viruses. The immune system reacts to foreign substances by a series of steps know as the immune repartee. some(prenominal) agent perceived as foreign by a bodys immune system is called an antigen. Several types of cells may be mixed in the immune response to antigens.         When an antigen enters the body, it may be partly neutralized by components of the born(p) immune system. It may be attacked by phagocytes or by performed antibodies that act together with the complement system. The homosexual immune system contains near 1 trillion T cells and 1 trillion B cells, located in the lymphoid organs and in the phone line, plus approximately 10 billion antigen-presenting cells located in the lymphoid organs. To maximize the chances of encountering antigens wherever they may invade the body, lymphocytes continually circulate between the breed and certain lymphoid tissues. A lymphocyte spends an average of 30 minutes per twenty-four hours in the blood and recirculates about 50 times per day between the blood and lymph! oid tissues.                  Lymphocytes... rather reminds you of a textbook summary. I would suggest having round keep of the sources used. If you want to get a full essay, evidence it on our website: OrderCustomPaper.com

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