Essentials of Anatomy & Physiology PDF

Essentials of Anatomy & Physiology, 4th Edition Martini / Bartholomew The Lymphatic 14 System and Immunity PowerPoint® Lecture Outlines prepared by Alan Magid, Duke University...

Essentials of Anatomy & Physiology, 4th Edition Martini / Bartholomew The Lymphatic 14 System and Immunity PowerPoint® Lecture Outlines prepared by Alan Magid, Duke University Slides 1 to 87 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization Lymphatic System Definitions Pathogens—Organisms that cause disease Lymphatic System —Cells, tissues, and organs that play a central role in the bodyʼs defenses against pathogens Lymphatic system consists of lymphatic vessels filled with lymph connected to lymphatic organs Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  Lymphatic System Organization The Components of the Lymphatic System Figure 14-1 Lymphatic System Organization Functions of the Lymphatic System 1. Produce, maintain, distribute lymphocytes Lymphocytes attack invading organisms, abnormal cells, foreign proteins 2. Maintain blood volume 3. Help keep local interstitial fluid concentrations level Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization Lymphatic Vessels Lymph fluid that flows inside Begin as lymphatic capillaries in the tissues Lymph empties into circulatory system At thoracic duct At right lymphatic duct Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization Lymphatic Capillaries Figure 14-2(a)  Lymphatic System Organization Lymphatic Capillaries Figure 14-2(b)  Lymphatic System Organization The Lymphatic Ducts and the Venous System Figure 14-3 Lymphatic System Organization Three Classes of Lymphocytes 1. T cells Thymus dependent 2. B cells Bone marrow derived 3. NK cells Natural Killer Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization Types of T Lymphocytes 1. Cytotoxic T cells Provide cell-mediated immunity Attack foreign and virus-infected cells 2. Regulatory T cells Helper T cells Suppressor T cells Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization B Lymphocytes 1. Can become plasma cells Specific to a particular antigen Produce antibodies that react with that antigen Antibodies are immunoglobulins 2. Responsible for humoral or antibody-mediated immunity Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization NK Lymphocytes 1. Provide immunological surveillance 2. Attack cells Foreign cells Virally-infected cells Cancerous cells Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization Lymphocyte Life Cycle Continuously migrate between lymphoid tissues and the blood Production and development (called lymphopoiesis) involves: Bone marrow Thymus Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization The Origins of Lymphocytes Figure 14-4 Lymphatic System Organization Lymphoid Nodules (like lymph nodes only different!) Consists of loose connective tissue containing densely packed lymphocytes Found in food and air passages Tonsils are lymphoid nodules in the pharynx wall 1. Pharyngeal (aka adenoids) 2. Palatine 3. Lingual Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization The Tonsils Figure 14-5 Lymphatic System Organization Lymphoid Organs Important lymphoid organs include: 1. Lymph nodes 2. Thymus 3. Spleen Located in areas that are vulnerable to pathogens Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization Lymph Nodes 1. What are they? Masses of lymphoid tissue containing lymphocytes 2. What do they do? Monitor and filter lymph Remove antigens Initiate immune response Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization The Structure of a Lymph Node Figure 14-6 Lymphatic System Organization The Thymus 1. Where? Lies behind sternum 2. What happens there? T cells divide and mature there 3. Shrinks after puberty 4. Produces thymosins Hormones that regulate T cell development Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization The Thymus Figure 14-7 Lymphatic System Organization The Thymus Figure 14-7(a) Lymphatic System Organization The Thymus Figure 14-7(b) Lymphatic System Organization The Thymus Figure 14-7(c) Lymphatic System Organization The Spleen White pulp Resembles lymphoid nodules Removes antigens Initiates immune response Red pulp Contains red blood cells Recycles damaged or out-dated RBCs Stores iron from recycled RBCs Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System Organization The Spleen Figure 14-8 Lymphatic System Organization The Spleen Figure 14-8(a) Lymphatic System Organization The Spleen Figure 14-8(b) Lymphatic System Organization Overview of Bodyʼs Defenses 1. Non-specific defenses (7 types) Protect against any threat 2. Specific defenses Protect against particular threats Responds to antigens Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Nonspecific Defenses 1. Physical Barriers Skin, hair, & skin secretions Digestive epithelia, & secretions Figure 14-9 (1 of 7) Nonspecific Defenses 2. Phagocytes Microphages (neutrophils, eosinophils) Macrophages Figure 14-9 (2 of 7) Nonspecific Defenses 3. Immunological Surveillance NK cells Find, kill cancer and virus-infected cells Figure 14-9 (3 of 7) Nonspecific Defenses 4. Interferons Small proteins released by virus-infected cells Cytokines that trigger release of anti-viral proteins that inhibit virus production Figure 14-9 (4 of 7) Nonspecific Defenses 5. Complement System Complex system of proteins Initiate chain reaction (positive feedback) Destroy target cell membranes Stimulate inflammation, attract phagocytes Figure 14-9 (5 of 7) Nonspecific Defenses 6. Inflammatory Response Coordinated non-specific response to tissue injury Figure 14-9 (6 of 7) Nonspecific Defenses 7. Fever Temperature greater than 99ºF Inhibits pathogens Accelerates metabolism Figure 14-9 (7 of 7) Nonspecific Defenses Events in Inflammation Figure 14-10 Specific Defenses: Immunity Types of Immunity 1. Innate immunity Genetically determined Present at birth 2. Acquired immunity Active Follows exposure to antigen Passive From transfer of antibodies from outside source Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Types of Immunity Figure 14-11 Specific Defenses: Immunity Properties of Specific Immunity Four general characteristics 1. Specificity 2. Versatility 3. Memory 4. Tolerance Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Properties of Specific Immunity 1. Specificity T and B cell membrane receptors recognize a unique antigen 2. Versatility Responsive to millions of antigens 3. Memory Memory cells recall earlier encounters with an antigen 4. Tolerance Ignores bodyʼs own antigens Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Overview of the Immune Response Purpose is to inactivate or destroy: Pathogens Abnormal cells Foreign molecules Based on activation of lymphocytes by specific antigens by antigen recognition Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  Direct physical and chemical attack CELL–MEDIATED IMMUNITY ANTIGENS Phagocytes T cells SPECIFIC activated activated Bacteria DEFENSES (Immune Communication response) and feedback ANTIBODY–MEDIATED IMMUNITY Viruses B cells activated Attack by circulating antibodies Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 1 of 7  ANTIGENS Bacteria Viruses Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 2 of 7  ANTIGENS SPECIFIC Bacteria DEFENSES (Immune response) Viruses Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 3 of 7  CELL–MEDIATED IMMUNITY ANTIGENS Phagocytes T cells SPECIFIC activated activated Bacteria DEFENSES (Immune response) Viruses Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 4 of 7  CELL–MEDIATED IMMUNITY ANTIGENS Phagocytes T cells SPECIFIC activated activated Bacteria DEFENSES (Immune Communication response) and feedback ANTIBODY–MEDIATED IMMUNITY Viruses B cells activated Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 5 of 7  Direct physical and chemical attack CELL–MEDIATED IMMUNITY ANTIGENS Phagocytes T cells SPECIFIC activated activated Bacteria DEFENSES (Immune Communication response) and feedback ANTIBODY–MEDIATED IMMUNITY Viruses B cells activated Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 6 of 7  Direct physical and chemical attack CELL–MEDIATED IMMUNITY ANTIGENS Phagocytes T cells SPECIFIC activated activated Bacteria DEFENSES (Immune Communication response) and feedback ANTIBODY–MEDIATED IMMUNITY Viruses B cells activated Attack by circulating antibodies Figure 14-12 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 7 of 7 Specific Defenses: Immunity T CELLS & CELL MEDIATED IMMUNITY 1.T Cell Activation (T cells are usually activated before B cells) T cells donʼt recognize antigens by themselves; usually recognize them when they are bound to receptors on other cell membranes T cells have specific receptors that detect these antigens Activated T cells differentiate further Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity 2. Differentiated Activated T Cells 1. Cytotoxic (killer) T cells Provide cell-mediated immunity Track down and attack bacteria, fungi, protozoa, or foreign transplanted tissues that contain the target antigen How? Produce toxins and other chemical compounds that get rid of antigen by: disrupting metabolism, genetically modifying target cell genes, or rupturing target cell membrane Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity 2. Helper T cells Secrete cytokines (chemical messengers like hormones) 2 jobs: 1). Coordinate specific and non-specific defenses 2). Stimulate both cell-mediated and antibody- mediated immunity Once activated Helper T cells will divide to produce more Helper T cells and Memory cells. They also have a function in B cell activation (coming up later…) Specific Defenses: Immunity 3. Memory T cells Remember the activating antigen “in reserve” When same antigen appears a second time, memory cells differentiate into cytotoxic T cells and helper T cells 4. Suppressor T cells Suppress other T and B cells Limit the degree of the immune response  ACTIVATION AND Infected cell CELL DIVISION Memory T Viral or cells (inactive) bacterial Class I antigen MHC protein Active cytotoxic Inactive T cell T cells cytotoxic receptor T cell Lymphotoxin Cytokine Perforin release release release Destruction of cell Disruption membrane of cell metabolism Stimulation of apoptosis Figure 14-13 Lysed cell DESTRUCTION 1 of 5 OF TARGET CELL Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  Infected cell Viral or bacterial Class I antigen MHC protein Inactive T cell cytotoxic receptor T cell Figure 14-13 2 of 5 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  ACTIVATION AND Infected cell CELL DIVISION Memory T Viral or cells (inactive) bacterial Class I antigen MHC protein Active cytotoxic Inactive T cell T cells cytotoxic receptor T cell Figure 14-13 3 of 5 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  ACTIVATION AND Infected cell CELL DIVISION Memory T Viral or cells (inactive) bacterial Class I antigen MHC protein Active cytotoxic Inactive T cell T cells cytotoxic receptor T cell Lymphotoxin Cytokine Perforin release release release Destruction of cell Disruption membrane of cell metabolism Stimulation of apoptosis Figure 14-13 4 of 5 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  ACTIVATION AND Infected cell CELL DIVISION Memory T Viral or cells (inactive) bacterial Class I antigen MHC protein Active cytotoxic Inactive T cell T cells cytotoxic receptor T cell Lymphotoxin Cytokine Perforin release release release Destruction of cell Disruption membrane of cell metabolism Stimulation of apoptosis Figure 14-13 Lysed cell DESTRUCTION 5 of 5 OF TARGET CELL Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Key Note Cell-mediated immunity depends on direct contact between cytotoxic T cells and foreign, abnormal, or infected cells. T cell activation usually involves antigen presentation by a phagocytic cell. Cytotoxic T cells destroy target cells with cytokines, lymphotoxins, or perforin. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity B CELLS & ANTIBODY-MEDIATED IMMUNITY 1. B cells are first sensitized by exposure to “their” antigen 2. Helper T cells for that antigen then activate those B cells 3. Activated B cells divide to form: Plasma cells Produce antibodies against that antigen Memory B cells Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings  Sensitization Activation Division and differentiation Class II Antigens MHC T cell receptor Antigen Class II MHC ANTIBODY PRODUCTION Antibodies B T Inactive B cell cell cell Antigens bound to antibody molecules Stimulation by cytokines Plasma cells Antigen binding Sensitized Helper T cell B cell Activated B cells Sensitized B cell Memory B cells (inactive) Figure 14-14 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 1 of 5  Sensitization Antigens Class II MHC Antibodies Inactive B cell Antigens bound to antibody molecules Antigen binding Sensitized B cell Figure 14-14 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 2 of 5  Sensitization Activation Class II Antigens MHC T cell receptor Antigen Class II MHC Antibodies B T Inactive B cell cell cell Antigens bound to antibody molecules Antigen binding Sensitized Helper T cell B cell Sensitized B cell Figure 14-14 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 3 of 5  Sensitization Activation Division and differentiation Class II Antigens MHC T cell receptor Antigen Class II MHC Antibodies B T Inactive B cell cell cell Antigens bound to antibody molecules Stimulation by cytokines Antigen binding Sensitized Helper T cell B cell Activated B cells Sensitized B cell Memory B cells (inactive) Figure 14-14 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 4 of 5  Sensitization Activation Division and differentiation Class II Antigens MHC T cell receptor Antigen Class II MHC ANTIBODY PRODUCTION Antibodies B T Inactive B cell cell cell Antigens bound to antibody molecules Stimulation by cytokines Plasma cells Antigen binding Sensitized Helper T cell B cell Activated B cells Sensitized B cell Memory B cells (inactive) Figure 14-14 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 5 of 5 Specific Defenses: Immunity Antibody Structure and Function Two pairs of parallel polypeptide chains Four Fixed segments Provides basic structure Four Variable segments Provides specific antigen-binding structure Antigen-antibody complex forms Antigen determinant site binds to antibody Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Antibody Structure Figure 14-15 Specific Defenses: Immunity Classes of Antibodies Immunoglobulin G (IgG) Resistance to pathogens Immunoglobulin M (IgM) First antibody secreted Immunoglobulin A (IgA) Found in glandular secretions Immunoglobulin E (IgE) Stimulates inflammation Immunoglobulin D (IgD) Found on surface of B cells Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity How Antibodies Can Eliminate Antigens 1. Neutralization -- bind to viruses or bacteria making them incapable of attaching to a cell 2. Precipitation -- 1 antibody can bind 2 antigens together and create a large complex. When it is insoluble in a body fluid (like bacterial toxin) it settles out 3. Agglutination -- formation of large complexes ; clumping of RBCʼs when incompatable blood types are mixed Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity 4. Complement System activation 5. Attraction of phagocytes 6. Stimulation of phagocytosis 7. Stimulation of inflammation Specific Defenses: Immunity Key Note Antibody-mediated immunity depends on specific antibodies from plasma cells derived from activated B cells by (1) antigen recognition, through binding to surface antibodies, and (2) stimulation by a helper T cell activated by the same antigen. The antibodies bind to the target antigen and either inhibit it, destroy it, remove it from solution, or promote its phagocytosis. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Primary and Secondary Immune Response Primary response—Antibodies produced by plasma cells after first exposure to antigen Secondary response—Maximum antibody levels produced by subsequent exposure to the same antibody Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity The Primary and Secondary Immune Responses Figure 14-16 Specific Defenses: Immunity Key Note Immunization produces a primary response to a specific antigen. If the same antigen is encountered at a later date, it triggers a powerful secondary response that usually prevents infection and disease. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Hormones of the Immune System Interleukins (IL) Sensitize T cells Stimulate B cells Enhance non-specific defenses Interferons Slow the spread of viruses locally Tumor necrosis factors (TNF) Slows growth, kills tumor cells Phagocytic regulators Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses: Immunity Key Note Viruses replicate inside cells, whereas bacteria usually live outside. Antibodies work outside of cells, so they are primarily effective against bacteria rather than viruses. T cells, NK cells, and interferons are the primary defenses against viral infection. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Immune Response A Summary of the Immune Response and Its Relationship to Nonspecific Defenses Figure 14-17 Patterns of Immune Response Immune Disorders Autoimmune disorders Mistaken attack on bodyʼs own tissues Immunodeficiency disease Result of some kind of infection (e.g., AIDS) or a congenital block of immunity; meaning immune system doesnʼt develop properly Allergies Inappropriate or excessive response to allergens Age-related loss of effectiveness Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Immune Response Types of Allergies 1. Immediate hypersensitivity (Type I) Hay fever causes inflammatory response 2. Cytotoxic reaction (Type II) Blood transfusion 3. Immune complex disorders (Type III) Inflammation in blood vessels and kidneys due to decreased phagocytosis 4. Delayed hypersensitivity (Type IV) Inflammatory response that occurs 2-3 days after exposure to an antigen (poison ivy) Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Immune Response Anaphylaxis: Type I Changes in capillary permeability produces swelling in the dermis Hives Smooth muscle in respiratory passages contracts Vasodialation causes BP to drop which leads to Anaphylactic Shock  The Lymphatic System in Perspective FIGURE 14-18 Functional Relationships Between the Lymphatic System and Other Systems Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 1 of 11 The Integumentary System Provides physical barriers to pathogen entry; macrophages in dermis resist infection and present antigens to trigger immune response; mast cells trigger inflammation, mobilize cells of lymphatic system Provides IgA antibodies for secretion onto integumentary surfaces Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 2 of 11 The Skeletal System Lymphocytes and other cells involved in the immune response are produced and stored in bone marrow Assists in repair of bone after injuries; macrophages fuse to become osteoclasts Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 3 of 11 The Muscular System Protects superficial lymph nodes and the lymphatic vessels in the abdominopelvic cavity; muscle contractions help propel lymph along lymphatic vessels Assists in repair after injuries Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 4 of 11 The Nervous System Microglia present antigens that stimulate specific defenses; glial cells secrete cytokines; innervation stimulates antigen-presenting cells Cytokines affect hypothalamic production of CRH and TRH Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 5 of 11 The Endocrine System Glucocorticoids have anti- inflammatory effects; thymosins stimulate development and maturation of lymphocytes; many hormones affect immune function Thymus secretes thymosins; cytokines affect cells throughout the body Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 6 of 11 The Cardiovascular System Distributes WBCs; carries antibodies that attack pathogens; clotting response helps restrict spread of pathogens; granulocytes and lymphocytes produced in bone marrow Fights infections of cardiovascular organs; returns tissue fluid to circulation Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 7 of 11 The Respiratory System Alveolar phagocytes present antigens and trigger specific defenses; provides oxygen required by lymphocytes and eliminates carbon dioxide generated during their metabolic activities Tonsils protect against infection at entrance to respiratory tract Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 8 of 11 The Digestive System Provides nutrients required by lymphatic tissues; digestive acids and enzymes provide nonspecific defense against pathogens Tonsils and lymphoid nodules of the intestine defend against infection and toxins absorbed from the digestive tract; lymphatics carry absorbed lipids to venous system Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 9 of 11 The Urinary System Eliminates metabolic wastes generated by cellular activity; acid pH of urine provides nonspecific defense against urinary tract infection Provides specific defenses against urinary tract infections Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 10 of 11 The Reproductive System Lysozymes and bactericidal chemicals in secretions provide nonspecific defense against reproductive tract infections Provides IgA antibodies for secretion by epithelial glands Figure 14-18 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 11 of 11