Evolution Of Immunity And The Invertebrates :: essays research papers

Evolution of license and the Invertebrates"Article Summery" conjure "Immunity and the Invertebrates" Periodical ScientificAmerican Nov, 1996 Author Gregory Beck and Gail S. Habicht Pages 60 - 71 TotalPages Read 9     The compound immune systems of humans and other(a) mammals evolved overquite a long time - in close to rather surprising ways. In 1982 a Russian zoologistnamed Elie Metchnikoff notice a unique property of starfish larva. When heinserted a extraneous object through its membrane, tiny cells would try to ingestthe invader through the process of phagocytosis. It was already known thatphagocytosis occurred in specialized mammal cells only when never in something lesscomplex like a starfish. This denudation led him to understand that phagocytosisplayed a much broader role, it was a sound mechanism of protection in theanimal kingdom. Metchnikoffs further studies showed that the host confessionsystem of all animals today were prese nt millions of years before when hey were undecomposed beginning to evolve. His studies opened up the new field of comparativeimmunology. proportional immunologists studied the immune defenses of past andcurrent creatures. They gained further insight into how ohmic resistance works.     The most basic requirement of an immune system is to distinguish amidones own cells and "non-self" cells. The second job is to exceed the non-self cells. When a abroad object enters the body, several things happen. Bloodstops flowing, the right system begins to eliminate unwanted microbes withphagocytic white blood cells. This defensive mechanism is have by allanimals with an innate system of ohmic resistance. Innate cellular immunity is believedto be the earliest form of immunity. Another form of innate immunity iscomplement, composed of 30 different proteins of the blood.     If these mechanisms do not work to foiling an invader, vertebrates relyon another response acquired immunity. Acquired immunity is mainly dealt byspecialized white blood cells called lymphocytes. Lymphocytes travel throughoutthe blood and lymph glands wait to attack molecules called antigens.Lymphocytes are made of twain classes B and T. B lymphocytes divulge antibodieswhile T help produce antibodies and serve to recognize antigens. AcquiredImmunity is highly effective but takes days to activate and succeed because ofits complex nature. Despite this, acquired immunity offers one great featureimmunological memory. immunologic Memory allows the lymphocytes to recognizepreviously encountered antigens making reaction time faster. For this reason, we cast immunizations or booster shots to children.     So it has been established that current vertebrates have two defensemechanisms innate and acquired, but what of older organisms ? Both mechanismssurprisingly overflowing can be found in almost all organisms (specifically