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Chapter 32. The Lymphatic and Immune Systems. PowerPoint® presentation to accompany: Medical Assisting Third Edition Booth, Whicker, Wyman, Pugh, Thompson. Learning Outcomes. 32.1 List the pathways and organs of the lymphatic system and give their locations.
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Chapter 32 The Lymphatic and Immune Systems PowerPoint® presentation to accompany: Medical Assisting Third Edition Booth, Whicker, Wyman, Pugh, Thompson
Learning Outcomes 32.1 List the pathways and organs of the lymphatic system and give their locations. 31.2 Define lymph and tell how it is circulated in the body. 31.3 Define the terms infection, pathogen, and antigen. 31.4 List and describe the nonspecific body defense mechanisms. 31. 5 Explain the signs and causes of inflammation.
Learning Outcomes (cont.) 32.6 Explain what is meant by body defenses. 32.7 Define B cells and T cells and describe their locations and functions. 32.8 Explain the importance of MHC proteins. 32.9 List the different types of T cells and describe their functions. 32.10 Explain how antibodies fight infection.
Learning Outcomes (cont.) 32.11 List the different types of antibodies and tell how they differ. 32.12 Define complement proteins and give their function. 32.13 Explain the difference between the primary immune response and secondary immune response. 32.14 Explain the four different types of acquired immunities. 32.15 Describe the function of a vaccine.
Learning Outcomes (cont.) 32.16 Define the terms cancer and carcinogen. 32.17 Describe how cancers are diagnosed and treated. 32. 18 Explain how cancers are classified. 32.19 Describe how allergies develop. 32.20 Describe the causes, signs and symptoms, and treatments of other common immune disorders.
Immune system Protects the body against Bacteria Viruses Fungi Toxins Parasites Cancer Lymphatic system Works with immune system to remove disease-causing agents Organs Thymus Spleen Lymph nodes Introduction
The Lymphatic System • Network of connecting vessels • Collects fluid (lymph) between cells and returns it to bloodstream • Picks up lipids from digestive organs and transports them to blood stream • Functions to defend the body against pathogens
Lymphatic capillaries Extend into interstitial spaces Permeable, thin walls pick up fluid, now lymph Delivers lymph to lymphatic vessels Lymphatic vessels Deliver lymph to lymph nodes Cells in nodes can remove pathogens from lymph and start an immune response Leaves nodes through efferent lymphatic vessels Lymph System Lymphatic System: Pathways
Lymphatic trunks Receive lymph from efferent lymphatic vessels Deliver it to Lymphatic collecting ducts Thoracic duct Left side of head and neck, left arm, left side of thorax, entire abdominopelvic area, and both legs Right lymphatic duct Right side of head and neck, right arm, and right side of chest Lymph System Lymphatic System: Pathways (cont.)
Lymphatic System: Tissue Fluid and Lymph • Interstitial fluid • Fluid in spaces between cells that has leaked from blood capillaries and has not been picked up by body cells • High in nutrients, oxygen, and small proteins • Becomes lymph • Pushed through lymphatic vessels by squeezing action of neighboring skeletal muscles and breathing movement
Lymphatic System: Nodes • Small, glandular structures • Located along paths of larger lymphatic vessels • Afferent lymphatic vessels – Lymph to node • Efferent lymphatic vessels – Lymph from node
Lymphatic System: Nodes (cont.) • More lymph enters than can leave at one time • Cells in nodes • Macrophages – digest unwanted pathogens • Lymphocytes – start an immune response against pathogen • Nodes can generate some lymphocytes
Thymus Soft, bi-lobed organ Located just above the heart in the mediastinum Large in children, shrinks as we age Functions Same as lymph nodes Also produces lymphocytes Produces thymosin – stimulates production of lymphocytes Lymphatic System: The Thymus and Spleen
Spleen Largest lymphatic organ Located in the upper left quadrant of abdominal cavity Functions Filters blood similarly to lymph nodes Removes worn-out red cells If removed (splenectomy), liver takes over most of its function Lymphatic System: The Thymus and Spleen (cont.)
Apply Your Knowledge What are the lymphatic collecting ducts and what area do they drain? • ANSWER: The collecting ducts are: • Thoracic duct, which drains the left side of the head and neck, left arm, left side of thorax, entire abdominopelvic area, and both legs; and the right lymphatic duct, which drains the right side of the head and neck, right arm, and right side of the chest. Correct!
Infection The presence of a pathogen in or on the body Pathogen A disease-causing agent Innate immunity Nonspecific defenses to protect against pathogens Nonspecific defenses Species resistance Mechanical barriers Chemical barriers Phagocytosis Fever Inflammation Defenses Against Disease
Immunities Protect against very specific pathogens Antigens Foreign substances in the body Haptens Foreign substances too small to start an immune response by themselves Other substances Proteins – antibodies and complements WBCs – lymphocytes and macrophages Lymph system Cytokines – assist in immune response regulation Monokines – increase B cell production and stimulate WBC production Defenses Against Disease: Specific Defenses
Response Defenses Against Disease (cont.) Two major types of lymphocytes B Cells and T Cells Recognize antigens in the body • B cells • Respond to antigens by becoming plasma cells • Plasma cells make antibodies • Memory B cells produce stronger response with next exposure to antigen • T Cells • Cell-mediated response • Bind to antigens on cells and attackthem directly • Secrete lymphokines that increase T cell production and directly kill cells with antigens
Defenses Against Disease (cont.) • T cell activation • Begins when macrophage ingests and digests pathogen with antigen on it • Antigens are placed on cell membrane of macrophage • T cell recognizes and binds to antigen and the major histocompatibility complex (MHC) on the surface of the macrophage • Now can divide to form other types of T cells
Types Cytotoxic T cells Protect body against viruses and cancer cells Helper T cells Increase antibody formation, memory cell formation, B cell formation, and phagocytosis Memory T cells Remember the pathogen that activated original T cell Later exposures trigger an immune response more effective than initial response Defenses Against Disease (cont.)
Defenses Against Disease (cont.) • Natural killer (NK) cells • Type of lymphocyte • Primarily target cancer cells • Kill on contact • Do not recognize a specific antigen
Apply Your Knowledge ANSWER: NK Identify whether each item refers to T cells, B cells, or NK cells: ___ Primarily target cancer cells ___ Respond to antigens by becoming plasma cells ___ Must be activated to respond to an antigen ___ Bind to antigens on cells and attack them directly ___ Kill on contact ___ Need macrophages and MHC for activation ___ Make antibodies against specific antigen Right on Target! B T T NK T B
Also called immunoglobulins IgA Prevents pathogens from entering body IgD Found on B cell membranes Thought to control B cell activity IgE Found with IgA Involved in triggering allergic reactions Antibodies
IgG Recognizes bacteria, viruses, and toxins Activates complements IgM Large and binds to antigens on food, bacteria, or incompatible blood cells Activates compliments Antibodies (cont.)
Antibodies (cont.) • Actions that occur when antibodies bind to antigens • Allow phagocytes to recognize and destroy antigens • Cause antigens to clump together, causing them to be destroyed by macrophages • Cover the toxic portions of antigens, making them harmless • Activate complement • Group of proteins in serum that attack pathogens by forming holes in them • Attract macrophages to pathogens and can stimulate inflammation
Apply Your Knowledge What are the possible actions that occur when antibodies bind to antigens? • ANSWER: Possible actions include: • They allow phagocytes to recognize and destroy antigens. • They make antigens clump together, causing them to be destroyed by macrophages. • They cover the toxic portions of antigens to make them harmless. • They activate complements. Very Good!
Immune Responses and Acquired Immunity • Primary immune response occurs with first exposure to antigen • Slow process • Memory cells are formed • Secondary immune response with next exposure to same antigen • Quick and carried out by memory cells • Usually prevents person from developing disease from the antigen
Immune Responses and Acquired Immunity (cont.) • Naturally acquired active immunity • Natural exposure to antigen – having an illness • Makes antibodies and memory cells • Long-lasting • Artificially acquired active immunity • Injected with pathogen – immunizations • Makes antibodies and memory cells • Long-lasting
Immune Responses and Acquired Immunity (cont.) • Naturally acquired passive immunity • Acquired from mother • Breast milk • Placenta • Short-lived • Artificially acquired passive immunity • Injected with antibodies (such as antivenom) • Short-lived
Apply Your Knowledge After you give an immunization to a 2-year-old, her mother asks you why this will work to prevent her from getting a disease. ANSWER: Immunization is an artificially acquired immunity because a person develops this immunity by being injected with a pathogen and then making antibodies and memory cells against the pathogen. Good Answer!
Major Immune System Disorders • Cancer • Uncontrolled growth of abnormal cells form malignant tumors • 200 known types • Treatment based on stage 0 – very early; cancer cells localized I – spread to deeper layers or some in surrounding tissues II – spread to surrounding tissues but contained in primary site III – spread beyond primary site into nearby areas IV – spread to other organs Recurrent – reappeared after treatment
Major Immune System Disorders (cont.) • Allergies • Immune response to an allergen • Can be excessive • IgE antibodies bind to allergens and stimulate mast cells to release histamine and heparin • Triggers allergic response • Allergy shots • Small amounts of allergen stimulates production of IgG to prevent IgE from binding to antigen • IgG antibodies do not stimulate mast cells, so immune response is not generated
Major Immune System Disorders (cont.) • Signs/symptoms • Inhaled allergens – runny nose, sneezing, coughing, wheezing • Ingested allergens – nausea, vomiting, diarrhea • Skin allergens – rashes • Allergens in blood – most life-threatening; can affect many organs • Treatment • Antihistamines, decongestants – OTC or prescription • Epinephrine for anaphylaxis – vasoconstriction, increasing BP • Anaphylaxis – life-threatening response
Common Immune System Disorders • Autoimmune disease • Body attacks its own antigens • Examples • Scleroderma • Rheumatoid arthritis • Multiple sclerosis • Glomerulonephritis • Chron’s disease • Diabetes mellitus, type I
Apply Your Knowledge ANSWER: Excellent! Matching: ___ Immune response to a substance A. CFS ___ Blockage of lymphatic vessels B. SLE ___ “Kissing disease” C. Cancer ___ “Butterfly” rash on face D. Autoimmune disease ___ Severe tiredness E. Lymphedema ___ Uncontrolled growth of abnormal cells F. Mononucleosis ___ Body attack its own antigens G. Allergy G E F B A C D
In Summary • Immune system is the body’s major line of defense • Primary function – protect against infection, toxins, and cancer • Specific or nonspecific defenses • Lymphocytes are major cells of immune system • Immune response may be primary or secondary • Medical assistant must understand immune system • Aseptic technique • Infection control • Educate patients
End of Chapter End of Chapter 32 Thought is an infection. In the case of certain thoughts, it becomes an epidemic. ~Wallace Stevens