Immune system new

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Immune system new

  1. 1. Immune SystemImmune System
  2. 2. A Boo Boo lets in germsA Boo Boo lets in germs
  3. 3. Like…BacteriaLike…Bacteria
  4. 4. Or a virusOr a virus
  5. 5. A germ is still a germ….A germ is still a germ…. 1.1. PathogenPathogen=agent that causes disease=agent that causes disease 22. Antigen. Antigen= foreign particle that triggers an= foreign particle that triggers an immune responseimmune response - often they are proteins on- often they are proteins on the surface of viruses andthe surface of viruses and bacteriabacteria
  6. 6. Your Body’s Defenses AgainstYour Body’s Defenses Against DiseaseDisease  Nonspecific Defenses: Attack allNonspecific Defenses: Attack all pathogens and antigens the same waypathogens and antigens the same way  Specific Defenses: Immune Response –Specific Defenses: Immune Response – Attack pathogens that get past theAttack pathogens that get past the nonspecific defensesnonspecific defenses
  7. 7. Nonspecific DefensesNonspecific Defenses This means that the identity of theThis means that the identity of the pathogen/antigen ispathogen/antigen is not importantnot important.. The response is the same if aThe response is the same if a bacteria, virus, splinter or bulletbacteria, virus, splinter or bullet invades the body.invades the body.
  8. 8. Nonspecific DefensesNonspecific Defenses First Line DefensesFirst Line Defenses  Skin: Forms a physical barrier to pathogensSkin: Forms a physical barrier to pathogens -oils and sweat make skin acidic – inhibits-oils and sweat make skin acidic – inhibits the growth of pathogensthe growth of pathogens -lysozyme-enzyme found in sweat and tears-lysozyme-enzyme found in sweat and tears digests bacterial cell wallsdigests bacterial cell walls  Mucus Membranes-layers of tissue whichMucus Membranes-layers of tissue which secrete mucussecrete mucus - found in body openings and the respiratory- found in body openings and the respiratory systemsystem - mucus traps pathogens- mucus traps pathogens
  9. 9. Nonspecific DefensesNonspecific Defenses Second Line DefensesSecond Line Defenses Inflammatory ResponseInflammatory Response  Damaged cells release histamines – chemical cry for helpDamaged cells release histamines – chemical cry for help - histamines cause blood vessels to dilate (open) bringing- histamines cause blood vessels to dilate (open) bringing blood to the area.blood to the area. - the dilated blood vessels become leaky releasing fluid and- the dilated blood vessels become leaky releasing fluid and white blood cells in the infected areawhite blood cells in the infected area - causes swelling and redness in the damaged area- causes swelling and redness in the damaged area - pus – fluid and dead cells forms- pus – fluid and dead cells forms  White Blood cellsWhite Blood cells - Macrophages –- Macrophages – “Big Eaters” engulf and kill pathogens“Big Eaters” engulf and kill pathogens - Neutrophils-- Neutrophils-engulf bactera and release chemicals thatengulf bactera and release chemicals that kill the bacteria and themselves.kill the bacteria and themselves. -- Natural Killer Cells –Natural Killer Cells – recognize and kill virus infectedrecognize and kill virus infected
  10. 10. Textbook page 925Textbook page 925 Histamines are released Blood vessels dilateHistamines are released Blood vessels dilate and leakand leak
  11. 11. MacrophageMacrophage
  12. 12. Nonspecific DefensesNonspecific Defenses Second Line Defenses (continued)Second Line Defenses (continued)  Temperature Response -Temperature Response - Fever –Fever – -Body temp increases in response to infection-Body temp increases in response to infection -pathogenic bacteria don’t grow well at higher temp-pathogenic bacteria don’t grow well at higher temp  ProteinsProteins -- Complement Proteins:Complement Proteins: kill pathogens by punching akill pathogens by punching a hole in the cell membranehole in the cell membrane - Intrerferon:- Intrerferon: a protein released by cells infected by virusesa protein released by cells infected by viruses -causes nearby cells to release an enzyme preventing the virus-causes nearby cells to release an enzyme preventing the virus from reproducingfrom reproducing
  13. 13. Fevers help eliminateFevers help eliminate pathogenspathogens
  14. 14. Specific DefensesSpecific Defenses  Third Line of DefenseThird Line of Defense Specific DefensesSpecific Defenses - identity of pathogen/- identity of pathogen/ antigen must be knownantigen must be known - the specific immune- the specific immune response is tailored toresponse is tailored to the specific pathogenthe specific pathogen
  15. 15. Specific DefensesSpecific Defenses Macrophage Links Nonspecific to SpecificMacrophage Links Nonspecific to Specific When a macrophage engulfs a pathogen, itWhen a macrophage engulfs a pathogen, it displays the viral antigen on its surfacedisplays the viral antigen on its surface The antigen is joined to a MHC (Major Histocompatibility Complex) The MHC is a protein on the surface of all vertebrate cells The anitgen must be bound to the MHC for the Helper T Cell to recognize it
  16. 16. Specific DefensesSpecific Defenses Helper T CellsHelper T Cells  Receptor proteins on helper T cells (TReceptor proteins on helper T cells (THH) bind to) bind to viral antigens displayed on the macrophageviral antigens displayed on the macrophage  causes macrophage tocauses macrophage to release Interleukin1release Interleukin1  Interleukin1 activatesInterleukin1 activates the helper T cells (Tthe helper T cells (THH))
  17. 17. Specific DefensesSpecific Defenses Helper T CellsHelper T Cells continuedcontinued  Activated helper T cells (TActivated helper T cells (THH) release proteins called) release proteins called cytokines which activate cytotoxic T cells (Tcytokines which activate cytotoxic T cells (TCC) and B cells) and B cells  The activated (TThe activated (TCC) and B cells begin to divide) and B cells begin to divide
  18. 18. Specific DefensesSpecific Defenses Cell Mediated ResponseCell Mediated Response  Receptor proteins on theReceptor proteins on the cytotoxic T cells (Tcytotoxic T cells (TCC) bind to) bind to viral antigens displayed byviral antigens displayed by infected cellsinfected cells  Cytotoxic T cells (TCytotoxic T cells (TCC) punch a) punch a hole in the cell’s membranehole in the cell’s membrane  Your body produces manyYour body produces many cytotoxic T cells (Tcytotoxic T cells (TCC))
  19. 19. Specific DefensesSpecific Defenses Antibody Mediated ResponseAntibody Mediated Response  B cells divide and develop intoB cells divide and develop into plasma cellsplasma cells  Plasma cells release large numbersPlasma cells release large numbers of antibodiesof antibodies  AntibodiesAntibodies bind to antigens onbind to antigens on pathogenspathogens  Antibodies cause pathogens to clumpAntibodies cause pathogens to clump holding them until macrophagesholding them until macrophages can engulf themcan engulf them  Antibodies are specific to a particular pathogen-yourAntibodies are specific to a particular pathogen-your body produces the antibodies in response to infectionbody produces the antibodies in response to infection
  20. 20. The Specific Defense has twoThe Specific Defense has two phasesphases  Primary ImmunePrimary Immune Response:Response: --Occurs when the bodyOccurs when the body has never encountered ahas never encountered a pathogen /antigen before.pathogen /antigen before. -Immune system goes-Immune system goes through all of the stepsthrough all of the steps -After the threat has-After the threat has passed,passed, MEMORY CellsMEMORY Cells are made.are made.  SecondarySecondary ImmuneImmune Response:Response: The next time theThe next time the pathogeninvadespathogeninvades MEMORY CellsMEMORY Cells identifyidentify the invader and athe invader and a massive volume ofmassive volume of antibodies are released,antibodies are released, destroying the invaderdestroying the invader before you feel ill.before you feel ill. You are immune!You are immune!
  21. 21. VaccinesVaccines Polio 1952 60,000 cases in the US 3000 fatalities 1955 Salk vaccine 1979 eliminated in US
  22. 22. How do vaccines work?How do vaccines work?  VaccinesVaccines are made up of weakened viralare made up of weakened viral particles.particles.  The weakened particles stimulate a smallThe weakened particles stimulate a small number of antibodies and memory cells tonumber of antibodies and memory cells to be produced.be produced. Primary Immune ResponsePrimary Immune Response  When a the pathogen attacks, theWhen a the pathogen attacks, the antibody production is larger.antibody production is larger. Secondary Immune ResponseSecondary Immune Response
  23. 23. Immune ResponseImmune Response
  24. 24. VocabularyVocabulary  Pathogen B cells T cellsPathogen B cells T cells  MacrophagesMacrophages  Nonspecific DefenseNonspecific Defense  VaccinesVaccines  Primary Immune ResponsePrimary Immune Response  Secondary Immune ResponseSecondary Immune Response

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