Chapter 43: The Immune Chapter 43: The Immune System System Disease Disease A departure from health A departure from health Types: Types: Deficiency diseases Deficiency diseases Genetic diseases Genetic diseases Communicable diseases Communicable diseases Contagious disease Contagious disease Infectious disease Infectious disease Host provides metabolic needs of pathogen Host provides metabolic needs of pathogen or parasite or parasite
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Chapter 43: The Immune Chapter 43: The Immune SystemSystem
DiseaseDiseaseA departure from healthA departure from healthTypes:Types:
Chemical shieldChemical shield Stomach acids kill bateriaStomach acids kill bateria Enzymes (lysozyme) in tears etc. Enzymes (lysozyme) in tears etc. Skin acidsSkin acids
Infected cells release interferonInfected cells release interferon Stimulate adjacent cells to produce proteins Stimulate adjacent cells to produce proteins
that prevent viral replicationthat prevent viral replication Activates phagocytesActivates phagocytes
33rdrd line: Immune response line: Immune response Production of LymphocytesProduction of Lymphocytes
Circulate in blood & lymphCirculate in blood & lymph Concentrated in spleen, lymph nodes, & Concentrated in spleen, lymph nodes, &
lymphoid tissuelymphoid tissue Each lymphocyte is specific to a particular Each lymphocyte is specific to a particular
foreign antigenforeign antigen Originate in stem cells of bone marrowOriginate in stem cells of bone marrow Types:Types:
B cellsB cells Mature in bone marrowMature in bone marrow
T cellsT cells Mature in thymus glandMature in thymus gland
Maturing B cells & T cells tested for self-Maturing B cells & T cells tested for self-reactivity & destroyed if self reactivereactivity & destroyed if self reactive
Production of specific antibodies by Production of specific antibodies by lymphocyteslymphocytes AntitoxinsAntitoxins
Clumping of bacteriaClumping of bacteria OpsoninsOpsonins
Stimulate phagocytosis of clumped bacteriaStimulate phagocytosis of clumped bacteria LysinsLysins
Dissolve cell walls of bacteriaDissolve cell walls of bacteria PrecipitinsPrecipitins
Coagulation chemicals of bacteriaCoagulation chemicals of bacteria
Immunoglobins (antibodies)Immunoglobins (antibodies) Specific antigen binding immunoglobulinsSpecific antigen binding immunoglobulins Generated by B cellsGenerated by B cells TypesTypes
IgMIgM First antibodies to arrive at infection siteFirst antibodies to arrive at infection site
IgCIgC Most abundant antibodies in blood & lymphMost abundant antibodies in blood & lymph
IgAIgA Antibodies found in body secretions (saliva, sweat)Antibodies found in body secretions (saliva, sweat)
IgEIgE Trigger release of histamines & other chemicals by Trigger release of histamines & other chemicals by
mast cells & basophils to cause allergic reactionsmast cells & basophils to cause allergic reactions IgDIgD
On naïve B cells (not yet exposed to foreign On naïve B cells (not yet exposed to foreign antigen)antigen)
Receives antigen that leads to clonal selectionReceives antigen that leads to clonal selection
Self/non-selfSelf/non-self Immune system must be able to Immune system must be able to
distinguish foreign from non-foreign distinguish foreign from non-foreign proteinsproteins
Major histocompatability complex (MHC)Major histocompatability complex (MHC) Group of glycoproteins embedded in cell Group of glycoproteins embedded in cell
membranemembrane Two major classes of MHCTwo major classes of MHC
Class I MHCClass I MHC Bind to cytotoxic T cellsBind to cytotoxic T cells
Class II MHCClass II MHC Known as antigen presenting cellsKnown as antigen presenting cells Bind to specialized cells (macrophages, B cells) & Bind to specialized cells (macrophages, B cells) &
activate T cellsactivate T cells
Action of lymphocytesAction of lymphocytes Humoral ResponseHumoral Response
B cellsB cells Enter blood & produce specific antibodies to counter Enter blood & produce specific antibodies to counter
specific antigensspecific antigens Antigen-antibody complexes are formedAntigen-antibody complexes are formed
Helper T cellsHelper T cells Secrete interleukinsSecrete interleukins
Stimulate clonin of B cells to memory cellsStimulate clonin of B cells to memory cells B cells into memory cells (M cells)B cells into memory cells (M cells)
Long lived cellsLong lived cells Recognize specific antigenRecognize specific antigen Basis of active immunityBasis of active immunity
Plasma cells (P cells)Plasma cells (P cells) Short lived cellsShort lived cells Produce additional antibodies with initial exposure to Produce additional antibodies with initial exposure to
antigenantigen Antibodies draw phagocytic cells in to destroyAntibodies draw phagocytic cells in to destroy
Cell mediated responseCell mediated response Cytotoxic T cellsCytotoxic T cells
Stored in thymus gland prior to moving into Stored in thymus gland prior to moving into bloodblood
Activated when CD8 receptors recognize Activated when CD8 receptors recognize antigen on Class I MHC; helper T cell antigen on Class I MHC; helper T cell releases cytokines to promote activationreleases cytokines to promote activation
Do not produce antibodiesDo not produce antibodies Attack & kill antigen-bearing cellsAttack & kill antigen-bearing cells
Secrete proteins that destroy infected cellsSecrete proteins that destroy infected cells Stimulate the production of B cellsStimulate the production of B cells
Dispose of infected cellsDispose of infected cells Suppress B cell reproduction when Suppress B cell reproduction when
infection has been suppressedinfection has been suppressed Secrete interferon which defends Secrete interferon which defends
healthy cells from virushealthy cells from virus
Primary vs. Secondary immune Primary vs. Secondary immune responseresponse
Primary immune responsePrimary immune response First exposure or vaccination to antigenFirst exposure or vaccination to antigen Results in formation a specific antibody to Results in formation a specific antibody to
inactivate an antigen inactivate an antigen Requires time to occurRequires time to occur
Secondary immune responseSecondary immune response Rapid reproduction of specific antibodies to Rapid reproduction of specific antibodies to
Types of DefenseTypes of Defense Innate immunityInnate immunity
Present at birth without any exposure Present at birth without any exposure Non-specificNon-specific
Acquired immunity/adaptive Acquired immunity/adaptive immunityimmunity Develops after exposureDevelops after exposure Highly specificHighly specific Recognition by lymphocytesRecognition by lymphocytes
Types of immunityTypes of immunity Natural immunityNatural immunity
Inherited immunity (parent to child)Inherited immunity (parent to child) Active immunityActive immunity
Long term immunity due toLong term immunity due to Exposure (i.e. chicken pox, mumps, Exposure (i.e. chicken pox, mumps,
measles)measles) VaccinationVaccination
Intentional exposure to weakened/dead pathogen Intentional exposure to weakened/dead pathogen or pathogenic toxinor pathogenic toxin
ImmunizationImmunization Polio...Polio...
Passive immunityPassive immunity Borrowed or temporary immunity Borrowed or temporary immunity
throughthrough Injection of antibodiesInjection of antibodies Blood serum or gamma globulin injectionsBlood serum or gamma globulin injections
Immediate immunityImmediate immunity Short term immunity Short term immunity
Memory cells are not producedMemory cells are not produced
Blood Groups effect on Blood Groups effect on transfusions & transplantstransfusions & transplants
Antibodies present against non-self Antibodies present against non-self blood types without exposureblood types without exposure result of reaction to bacterial antigensresult of reaction to bacterial antigens
MHC molecules stimulate immune MHC molecules stimulate immune response leading to tissue rejectionresponse leading to tissue rejection each person has a unique polymorphic each person has a unique polymorphic
combination of MHC moleculescombination of MHC molecules
Exaggerated, self-directed or Exaggerated, self-directed or diminished immune response & diminished immune response &
diseasedisease AllergiesAllergies
Hypersensitive response to antigens on Hypersensitive response to antigens on allergensallergens
Often involve IgE antibodiesOften involve IgE antibodies Attach to mast cells to induce histamine Attach to mast cells to induce histamine
Immunodeficiency diseasesImmunodeficiency diseases Inborn or primaryInborn or primary
Caused by genetic or developmental defectCaused by genetic or developmental defect Defect in production of immune cells or Defect in production of immune cells or
specific proteinsspecific proteins Acquired or secondaryAcquired or secondary
Develops later in lifeDevelops later in life Caused by exposure to agents or diseaseCaused by exposure to agents or disease Ex. Hodgkin's, AIDSEx. Hodgkin's, AIDS