immunesystem

31.1PathogensandHumanIllnessKEYCONCEPTGermscausemanydiseasesinhumans.31.1PathogensandHumanIllnessGermtheorystatesthatmicroscopicparticlescausecertaindiseases.•Germtheoryproposesthatmicroorganismscausediseases.–proposedbyLouisPasteur–ledtorapidadvancesinunderstandingdisease31.1PathogensandHumanIllness•Disease-causingagentsarecalledpathogens.•Koch’spostulatessupportthetheory.31.1PathogensandHumanIllnessTherearedifferenttypesofpathogens.•Bacteriaaresingle-celledorganisms.–causeillnessbydestroyingcells–releasetoxicchemicals31.1PathogensandHumanIllness•Virusesaregeneticmaterialsurroundedbyaproteincoat.–forcehostcellstomakemoreviruses–verysmall31.1PathogensandHumanIllness•Fungicanbemulticellularorsingle-celled.–takenutrientsfromhostcells–occurinwarmanddampplaces31.1PathogensandHumanIllness•Protozoaaresingle-celledorganisms.–usehostcellstocompletetheirlifecycles–takenutrientsfromhostcell31.1PathogensandHumanIllness•Parasitesaremulticellularorganisms.–growandfeedonahost–possiblykillthehost31.1PathogensandHumanIllness•Differentpathogencausecommoninfectiousdiseases.31.1PathogensandHumanIllnessPathogenscanenterthebodyindifferentways.•Pathogenscanbetransferredbydirectorindirectcontact.•Indirectcontactdoesnotrequiretouchinganinfectedindividual.–touchinganinfectedsurface–breathingininfectedair31.1PathogensandHumanIllness•Vectorscarryapathogenandtransmititintohealthycells.•Directcontactrequirestouchinganinfectedindividual.Includes:–kissing–sexualintercourse–handshakingtick31.2ImmuneSystemKEYCONCEPTTheimmunesystemsconsistsoforgans,cells,andmoleculesthatfightinfections.31.2ImmuneSystemManybodysystemsprotectyoufrompathogens.•Theimmunesystemisthebodysystemthatfightsoffinfectionandpathogens.•Manyothertissuesandsystemshelptheimmunesystem.–Skinisaphysicalbarriertoinfection.–Mucousmembranestrappathogensenteringthebody.–Thecirculatorysystemtransportsimmunecells.31.2ImmuneSystemCellsandproteinsfightthebody’sinfections.•Whitebloodcellsattackinfectionsinsidethebody.–Phagocytesengulfanddestroypathogens.–Tcellsdestroyinfectedcells.–Bcellsproduceantibodies.31.2ImmuneSystem•Threetypesofproteinsfightoffinvadingpathogens.–Complementproteinsweakenpathogenmembranes.–Antibodiesmakepathogensineffective.–Interferonspreventvirusesfrominfectinghealthycells.antibodypathogens31.2ImmuneSystemImmunitypreventsapersonfromgettingsickfromapathogen.•Inallimmunity,pathogensaredestroyedbeforeyougetsick.•Passiveimmunityoccurswithoutanimmuneresponse.–mother’smilk–genetics•Activeimmunityoccursafteraspecificimmuneresponse31.3ImmuneResponsesKEYCONCEPTTheimmunesystemhasmanyresponsestopathogensandforeigncells.31.3ImmuneResponsesManybodysystemsworktoproducenonspecificresponses.•Nonspecificresponsesarethesameforeverypathogen.•Ininflammation,bloodvesselsbecomeleaky.–whitebloodcellsmovetowardinfectionanddamagedtissue–characterizedbyswelling,redness,andpaincapillarywallextracellularspacewhitebloodcell31.3ImmuneResponses•Infever,bodytemperatureincreases.–Highfeverscancauseseizure,braindamage,andevendeath.–Lowfeversstimulatewhitebloodcellstomature.31.3ImmuneResponsesCellsoftheimmunesystemproducespecificresponses.•Specificimmuneresponsesbeginwiththedetectionofantigens.–Antigensaresurfaceproteinsonpathogens.–Eachpathogenhasadifferentantigen.virusantigens31.3ImmuneResponsespathogenantigensTcellreceptorsactivatedTcellsantigensmemoryTcells•Therearetwospecificimmuneresponses.–CellularimmunityusesTcellstodestroyinfectedbodycells.31.3ImmuneResponses•Therearetwospecificimmuneresponses.–HumoralimmunityusesBcellstoproduceantibodies.memoryBcellsactivatedBcellsantibodiesBcellTcellpathogen31.3ImmuneResponses•Bothresponsesproducememorycells.–specializedTandBcells–provideacquired(active)immunityBcellTcell31.3ImmuneResponsesTheimmunesystemrejectsforeigntissues.•Tissuerejectionoccursinorganortissuetransplants.•Tissuerejectionistheresultofanimmuneresponse.–immunesystemdetectsproteinmarkersonthedonortissue–makesantibodiesagainstthedonor’stissue31.4ImmunityandTechnologyKEYCONCEPTLivinginacleanenvironmentandbuildingimmunityhelpkeepapersonhealthy.31.4ImmunityandTechnologyManymethodsareusedtocontrolpathogens.•Antibioticsandantisepticscausepathogenstoburst.31.4ImmunityandTechnology•Antisepticskillpathogensoutsideofthebody.–donottargetspecificpathogens–examplesincludevinegarandsoap•Antibioticskillpathogensinsidethebody.–targetonespecificbacteriumorfungus–noteffectiveagainstviruses31.4ImmunityandTechnology•Antibioticresistancecancausemedicinestobecomeineffective.–Somebacteriainapopulationhavegenesthatmakethemimmunetoantibiotics.–Thesebacteriaspreadthegene,makingtheantibioticsuseless.Abacteriumcarriesgenesforantibioticresistanceonaplasmid.Acopyoftheplasmidistransferredthroughconjugation.Resistanceisquicklyspreadthroughmanybacteria.31.4ImmunityandTechnologyVaccinesartificiallyproduceacquiredimmunity.•Vaccinesalsocontrolpathogensanddisease.–giventopreventillness–containtheantigenofaweakenedpathogen31.4ImmunityandTechnology•Vaccinationprovidesimmunity.–stimulatesaspecificimmuneresponse–allowsimmunesys