Michael Anderson EXSC 224-001 Prof. Thompson June 16, 2016 Assignment #4 1. Describe the inflammatory process. Identify several inflammatory chemicals and indicate their specific roles. Inflammation is an immune response in areas of infection or tissue injury. Inflammation helps to seal off and prevent the spread of infection, dispose of damaged cells or pathogens and begin the repair or healing process. The inflammatory process is induced by the release of certain chemical messengers such as histamines, kinins, and prostaglandins. Histamines are released by tissue cells in response to injury or when in the presence of foreign microorganisms. It promotes the localized vasodilation of arterioles; allowing for increased blood flow to the affected area, increasing the metabolic rate of cells in said area to increase rate of repair and can result in swelling or redness. Prostaglandins and kinins also trigger vasodilation similarly to histamine but they also promote chemotaxis of neutrophils and macrophages to the area of injury to begin fighting infection and clearing damaged cells. Chemicals released by these neutrophils or macrophages can stimulate the nerve ending in the area and produce a sense of pain. This sense of pain theoretically makes one less willing to move or use the damaged area to allow for the healing process to take place. 2. Describe the complement system. Include the different mechanisms by which the system can be activated as well as the different possible outcomes. The complement system consists of proteins circulating through the blood that assist in the elimination of alien substances or organisms from the body. Activation of the complementsystem leads to the before mentioned inflammatory process and eventually the lysis or destruction of the threat. Activation can occur in any one of three ways. The Classical Pathway relies on the presence of antibodies from the adaptive immune system, these antibodies coat the outside of the foreign organism and also bind to the complement proteins. This pathway links the adaptive and innate immune system. The Lectin Pathway involves the use of lectins produced by the innate immune system. Lectin binds to the Glycocalyx of the pathogen in a similar manor that antibodies would bind to the membrane as in the classical pathway. These bound lectin also bind to the complement proteins. The Alternative Pathway is the most simple, normal body cells possess self-antigens that signal the complement proteins to pass by them without binding, foreign bodies lack these self-antigens and allow for complement proteins to bind to them. Activation of any of the above mentioned pathways leads to one of three responses. Opsinization response causes the coating of the pathogens with proteins, these proteins serve as a flag for macrophages to phagocytize the threat. The enhanced Inflammation response stimulates the release of inflammatory chemicals and cause localized inflammation and the chemotaxis of neutrophils and phagocytes to fight infection and clean the affected area. Lastly the Membrane Attack Complex or MAC response involves the creation of multiple MAC proteins that pierce the pathogens membrane and form a pore. This pore compromises the pathogens ability to regulate its internal environment and eventually cause it to lyse. 3. Define complete antigen, hapten, and antigenic determinant. The term complete antigen refers to an antigen that possess the properties of immunogenicity and reactivity. Immunogenicity refers to the ability to stimulate naïvelymphocytes to mature and multiply. Reactivity refers to the ability to react with the newly created lymphocytes. When an antigen possess the reactive property yet lacks the immunogenic property it is known as a Hapten. Haptens can react to the lymphocytes meant to combat it but complication arises from the fact that it cannot elicit the creation of these lymphocytes on its own, it must bind with a protein within in the host to stimulate the adaptive immune system to create the lymphocytes. Antigenic determinants are the immunogenic regions found on the surface of antigens which elicit the creation specific antibodies and specialized lymphocytes. 4. Describe T cell functions in the body. T Cells are the non-antibody producing lymphocytes of the adaptive immune system. T cells are cultivated to be both immunocompetent and self-competent, meaning they recognize the cells of the host and do not react to them. Matured T Cells are separated into two sub groups, CD4 cells which bare MHC II receptors and CD8 cells that bare MHC I receptors. These cells sit dormant and naïve until they are introduced to APC’s bearing their receptive MHC proteins and change into their active state. When CD4 cells are activated they proliferate into Helper T Cells. These cells increase the rate and intensity of immune response by further activating B Cells and memory B Cells to produce more plasma cells that create antibodies. Helper T Cells also stimulate the activation of Cytotoxic cells and allow them to lyse the APC’s. The Cytotoxic cells arise from activated CD8 Cells. These cells contain Granzymes and Perforins that pierce the membrane of the APC to forms pores and degrade its proteins, ultimately killing off the threat. Helper T cells also serve a regulatory function. They assist in regulating immuneresponse by wither directly binding to lymphocytes or by releasing inhibitory chemical signal or