Chapter 22, part 2The ThymusFigure 22.8 The ThymusThe SpleenFigure 22.9 The SpleenLymphatic system and body defensesSECTION 22-3 Nonspecific DefensesNonspecific Defenses, Physical barriersFigure 22.10 Nonspecific Defenses (Part 1 - Physical Barriers)Nonspecific Defenses, PhagocytesFigure 22.10 Nonspecific Defenses (Part 2 - Phagocytes)Nonspecific Defenses, Immunological surveillanceNK cell activationFigure 22.10 Nonspecific Defenses (Part 3 - Immunological Surveillance)Figure 22.11 How Natural Killer Cells Kill Cellular TargetsNonspecific Defenses, Interferons (cytokines)Figure 22.10 Nonspecific Defenses (Part 4 - Interferons)Nonspecific Defenses, Complement systemComplement proteins interact with on another via two pathwaysFigure 22.10 Nonspecific Defenses (Part 5 - Complement System)Figure 22.12 Complement ActivationNonspecific Defenses, InflammationFigure 22.10 Nonspecific Defenses (Part 6 - Inflammatory Response)Figure 22.13 InflammationNonspecific Defenses, FeverFigure 22.10 Nonspecific Defenses (Part 7 - Fever)Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & PhysiologySIXTH EDITIONFrederic H. MartiniPowerPoint® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, HawaiiChapter 22, part 2The Lymphatic System and ImmunityCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Located behind sternum in anterior mediastinum•Capsule•Two lobes•Divided into lobules, each with a cortex and medulla•Cortical lymphocytes surrounded by reticular endothelial cells •Maintain blood–thymus barrier•Secretes thymic hormones: thymosins, thymopoietins, and thymulinThe ThymusCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.8 The ThymusFigure 22.8a-cCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Largest mass of lymphoid tissue•Cellular components form pulp•Red pulp contains RBC•White pulp similar to lymphoid nodules•Spleen functions include•Removal of abnormal blood cells and other blood components•Storage of iron •Initiation of the specific immune responseThe SpleenCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.9 The SpleenFigure 22.9a-cCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Nonspecific defenses•Do not distinguish one type of threat from another•7 types•Specific defenses•Protect against particular threats•Depend upon the activation of lymphocytesLymphatic system and body defensesCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsSECTION 22-3 Nonspecific DefensesCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Keep hazardous organisms outside the body•Includes hair, epithelia, secretions of integumentary and digestive systemsNonspecific Defenses, Physical barriersCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.10Figure 22.10 Nonspecific Defenses (Part 1 - Physical Barriers)Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Remove cellular debris and respond to invasion by foreign pathogens•Monocyte-macrophage system - Fixed and free•Microphages – Neutrophils and eosinophils•Move by diapedesis•Exhibit chemotaxisNonspecific Defenses, PhagocytesCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.10 Nonspecific Defenses(Part 2 - Phagocytes)Figure 22.10Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Constant monitoring of normal tissue by NK cells•NK cells•Recognize cell surface markers on foreign cells•Destroy cells with foreign antigensNonspecific Defenses, Immunological surveillanceCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsNK cell activation•Recognition of unusual surface proteins•Rotation of the Golgi toward the target cell and production of perforins•Release of perforins by exocytosis•Interaction of perforins causing cell lysisCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.10Figure 22.10 Nonspecific Defenses(Part 3 - Immunological Surveillance)Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.11Figure 22.11 How Natural Killer Cells Kill Cellular TargetsCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsNonspecific Defenses, Interferons (cytokines)•Small proteins released by virally infected cells•Trigger the production of antiviral proteins •Three major types of interferons are:•Alpha– produced by leukocytes and attract/stimulate NK cells•Beta– secreted by fibroblasts causing slow inflammation •Gamma – secreted by T cells and NK cells stimulate macrophage activityCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.10 Nonspecific Defenses(Part 4 - Interferons)Figure 22.10Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsNonspecific Defenses, Complement system•Cascade of ~11 plasma complement proteins (C) •Destroy target cell membranes•Stimulate inflammation•Attract phagocytes•Enhance phagocytosisCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsComplement proteins interact with on another via two pathways•Classical•AlternativeCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.10Figure 22.10 Nonspecific Defenses(Part 5 - Complement System)Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.12 Complement ActivationFigure 22.12Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsNonspecific Defenses, Inflammation•Localized tissue response to injury producing•Swelling•Redness•Heat•Pain•Effects of inflammation include•Temporary repair of injury•Slowing the spread of pathogens •Mobilization of local, regional, and systemic defensesCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.10 Nonspecific Defenses(Part 6 - Inflammatory Response)Figure 22.10Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 22.13 InflammationFigure 22.13Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsNonspecific Defenses, Fever•Maintenance of a body temperature above 37.2oC (99oF)•Pyrogens