chapt22_lecture-2 - 22-1ImmunityAbility to resist damage...

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Unformatted text preview: 22-1ImmunityAbility to resist damage from foreign substances such as microorganisms and harmful chemicalsCategoriesInnateor nonspecific resistanceMechanical mechanisms: prevent entry or remove microbes. Skin, tears, saliva, mucous membranes, mucus. Considered the acid mantleChemical mediators: promote phagocytosis and inflammationCells: involved in phagocytosis and production of chemicals Adaptiveor specific immunitySpecificity: ability to recognize a particular substanceMemory: ability to remember previous encounters with a particular substance and respond rapidly22-2Adaptive ImmunityInvolves the ability to recognize, respond to ( immunocompetence) , and remember a particular substance ( memory) StimulantsAntigens: large moleculesForeign: not produced by body, introduced from outside. Bacteria, viruses, other microorganisms that cause diseasePollen, animal dander, feces of mites, foods, drugs cause overreaction of immune system called allergic reaction.Self-antigens: produced by body. Used as markers to allow adaptive immune response to differentiate self from non-self. Response to self tumor antigens helpfulResponse to self-antigens resulting in tissue destruction: auto immune diseasesHaptens: small molecules, combine with large proteins and producing an adaptive immune response.TypesHumoralor Antibody-mediated: B cellsCell-mediated: T cells ( make distinctive proteins inserted in plasma membrane they are antigen receptors and recognize specific antigens ( CD4 or CD8) CD8 are cytotoxic T cells ( cells attacking cells ) CD4 cells become T helper cells and activate cell mediated and antibody activation 22-322-4Origin and Development of LymphocytesPositive selectionEnsures survival of lymphocytes that react against antigens. These then proliferate and form clones....
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chapt22_lecture-2 - 22-1ImmunityAbility to resist damage...

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