The Diseases Vaccines Prevent and How - John A. Ferguson ...



Immune SystemAgents of Infectious Diseases are called pathogensVirus bacteriafungi parasites ( worms, animals, & insects)Types of ResponsesNonspecific Immune ResponseSkin biggest line of defenseSecretions (e.g. tears, mucous, saliva) they washInflammatory ResponseFeverFirst line of defense - Surface coverageThe body is protected from pathogens by the skin (first line of defense) and mucous membranes Skin - dead cellular layer - dry, low pH of sweat Mucous membranes contain lysozymes (enzymes which break down bacteria) Other cells contain cilia which filter pathogens and particulates Breaks in the protective barrier Digestive openings Reproductive openings Respiratory openings Sensory Organs Non-specific responses - the second line of defenseNon-specific responses are generalized responses to pathogen infection they simply provide a barrier like a castle wall - they do not target a specific cell type A second line of defense is an inflammatory response when a pathogen makes it into the body. The pathogen stimulates an increase in blood flow to the infected area. Blood vessels in that area expand, and white blood cells leak from the vessels to invade the infected tissueThe non-specific response consist of some WBC's and plasma proteins released by blood vessels.Inflammation Causes localized redness, swelling, heat, and pain Changes in capillary wall structure allow interstitial fluid and WBC's to leak out in tissue Promotes macrophage (phagocytic WBC's) activity Macrophages secrete Interleukins (communication proteins among WBC's) Interleukin-1: increases body temperature (i.e. causes a fever) This enhances the WBC's ability to protect the body A second line of defense is an inflammatory response when a pathogen makes it into the body. The pathogen stimulates an increase in blood flow to the infected area. Blood vessels in that area expand, and white blood cells leak from the vessels to invade the infected tissue.The Immune System (Specific Responses) – third line of defenseCalled into action when nonspecific methods are not enough and infection becomes widespread Interferons are a group of signaling proteins[1] made and released by host cells in response to the presence of several viruses. A virus-infected cell will release interferons causing nearby cells to heighten their anti-viral defenses killing the virusTypes of cells involved in the immune system: Macrophages - engulf foreign objects Helper T cells B Each type of virus, bacteria, or other foreign body has molecular markers which make it unique Memory cells - become dormant, but can be triggered to rapid mitosis if pathogen encountered again Terms to KnowAntigen - a nonspecific marker (flag) that triggers the formation of lymphocyte armies Antibodies - molecules which bind to antigens and are recognized by lymphocytes Memory b recognize the specific virus faster and The B-cells produce antibodies more quickly if the virus is encountered again.Active Immunity has two type:Cell-mediated immune response (steps 1-5)Antibody-mediated immune response (steps 3-5)The Diseases Vaccines Prevent and HowAcquired Immunity: immunity to a particular disease that is not innate but has been acquired during life; immunity can be acquired by the development of antibodies after an attack of an infectious disease or by a pregnant mother passing antibodies through the placenta to a fetus or by vaccination Artificial immunity is classified as active and comes in the form of vaccinations, typically give to children and young adults. The passive form of artificial immunity involves introducing an antibody into the system once a person has already been infected with a disease, ultimately relieving the present symptoms of the sickness and preventing re-occurrence.Passive Immunity: an impermanent form of acquired immunity in which antibodies against a disease are acquired naturally (as through the placenta to an unborn child) or artificially (as by injection of antiserum) short term affect ................
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