MSU BIO216 Lecture - Week 7-8 Objective Assignment

MSU BIO216 Lecture - Week 7-8 Objective Assignment -...

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BIOL216 Lecture Week 7-8 Objective Assignment Chapter 21: The Immune System: Innate and Adaptive Body Defenses PART 1: INNATE DEFENSES Surface Barriers: Skin and Mucosae 1. Describe surface membrane barriers and their protective functions. Surface membrane barriers, such as skin and mucous membranes, are the body's first line of defense against most microorganisms. Acidity of skin inhibits bacterial growth, stomach mucosa secretes concentrated hydrochloric acid solution and protein-digesting enzymes - both of which kill microorganisms, saliva cleanses the oral cavity and teeth, lysozyme destroys bacteria in the lacrimal fluid of the eyes, and then sticky mucus traps many microorganisms that enter the digestive and respiratory passageways. Internal Defenses: Cells and Chemicals 1. Explain the importance of phagocytosis and natural killer cells in innate body defense. Not only does phagocytosis allow us to remove potentially deadly invaders, it is also important in maintenance of healthy tissues. Without this mechanism, nonfunctional materials would accumulate and interfere with the body's ability to function. 2. Explain how fever helps protect the body. Fever is manifested with high body temperature to protect the body against infections and diseases. Mild or moderate fever is often helpful as it helps our immune system increase white blood cells, produce antibodies and infection-fighting agents to fight off harmful bacteria and viruses in the body. PART 2: ADAPTIVE DEFENSES Antigens 1. Define antigen and describe how antigens affect the adaptive defenses. Antigen - a molecule recognized by the immune system. Adaptive defense is the binding of pathogens trapped by the innate immune system. Requirements for potential targets by innate immune recognition: 1. Molecular patterns recognized by the innate immune system must be shared by large groups of pathogens, and thus must represent general patterns rather than specific structures. 2. These molecular patterns must be conserved products of microbial metabolism, which are not subject to antigenic variability. Although the immune system selects against these patterns, pathogens cannot 'change' them because they are essential for the survival or pathogenicity of the microorganisms. Any attempts to change them, will be lethal to the microbe or render it nonpathogenic. 3. The overall effect of immune recognition and the destruction of the target require that the recognized structures be distinct from self-antigens. The major consequence of this requirement is the ability of the innate immune system to discriminate between self and nonself.
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BIOL216 Lecture Week 7-8 Objective Assignment Cells of the Adaptive Immune System: An Overview 1. Compare and contrast the origin, maturation process, and general function of B and T lymphocytes. There are different types of B cell and T cell. Both are lymphocytes, a subclass of white
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MSU BIO216 Lecture - Week 7-8 Objective Assignment -...

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