The Lymphatic and Immune Systems - McGraw-Hill_19161：淋巴系统和免疫系统mcgraw-hill_19161

1、28The Lymphatic and Immune Systems28-2Learning Outcomes28.1List the pathways and organs of the lymphatic system and give their locations.28.2Define lymph and tell how it is circulated in the body.28.3Define the terms infection, pathogen, and antigen.28.4List and describe the nonspecific body defense

2、 mechanisms.28.5Explain the signs and causes of inflammation. 28-3Learning Outcomes (cont.)28.6Explain what is meant by body defenses.28.7Define B cells and T cells and describe their locations and functions.28.8 Explain the importance of MHC proteins.28.9 List the different types of T cells and des

3、cribe their functions.28.10Explain how antibodies fight infection.28-4Learning Outcomes (cont.)28.11List the different types of antibodies and tell how they differ.28.12Define complement proteins and give their function.28.13Explain the difference between the primary immune response and secondary im

4、mune response.28.14Explain the four different types of acquired immunities.28.15Describe the function of a vaccine.28-5Learning Outcomes (cont.)28.16Define the terms cancer and carcinogen.28.17Describe how cancers are diagnosed and treated.28.18Explain how cancers are classified.28.19Describe how al

5、lergies develop.28.20Describe the causes, signs and symptoms, and treatments of other common immune disorders.28-6Introduction Immune system Protects the body againstBacteria Viruses Fungi Toxins Parasites CancerLymphatic systemWorks with immune system to remove disease-causing agentsOrgansThymusSpl

6、eenLymph nodes28-7The Lymphatic SystemNetwork of connecting vessels Collects fluid (lymph) between cells and returns it to bloodstreamPicks up lipids from digestive organs and transports them to bloodstreamFunctions to defend the body against pathogens28-8Lymphatic PathwaysLymphatic capillariesExten

7、d into interstitial spacesPermeable, thin walls pick up fluid, now lymphDelivers lymph to lymphatic vesselsLymphatic vessels Deliver lymph to lymph nodesCells in nodes can remove pathogens from lymph and start an immune responseLeaves nodes through efferent lymphatic vesselsLymph System28-9Lymphatic

8、 Pathways (cont.)Lymphatic trunksReceive lymph from efferent lymphatic vessels Deliver it to Lymphatic collecting ductsThoracic ductLeft side of head and neck, left arm, left side of thorax, entire abdominopelvic area, and both legsRight lymphatic duct Right side of head and neck, right arm, and rig

9、ht side of chestLymph System28-10Tissue Fluid and LymphInterstitial fluidFluid in spaces between cells that has leaked from blood capillaries and has not been picked up by body cellsHigh in nutrients, oxygen, and small proteinsBecomes lymphPushed through lymphatic vessels by squeezing action of neig

10、hboring skeletal muscles and breathing movement28-11Back28-12Lymph NodesSmall, glandular structuresLocated along paths of larger lymphatic vesselsAfferent lymphatic vessels Lymph to nodeEfferent lymphatic vessels Lymph from node28-13Lymph Nodes (cont.)More lymph enters than can leave at one timeCell

11、s in nodesMacrophages digest unwanted pathogensLymphocytes start an immune response against pathogenNodes can generate some lymphocytes28-14The Thymus and SpleenThymus Soft, bi-lobed organLocated just above the heart in the mediastinumLarge in children, shrinks as we ageFunctions Same as lymph nodes

12、Also produces lymphocytesProduces thymosin stimulates production of lymphocytes28-15The Thymus and Spleen (cont.)SpleenLargest lymphatic organLocated in the upper left quadrant of abdominal cavityFunctionsFilters blood similarly to lymph nodesRemoves worn-out red cellsIf removed (splenectomy), liver

13、 takes over most of its function28-16Apply Your KnowledgeWhat 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

14、 the right lymphatic duct, which drains the right side of the head and neck, right arm, and right side of the chest.Correct!28-17Defenses Against DiseaseInfection The presence of a pathogen in or on the bodyPathogen A disease-causing agentInnate immunityNonspecific defenses to protect against pathog

15、ensNonspecific defensesSpecies resistanceMechanical barriersChemical barriersPhagocytosisFeverInflammation 28-18Specific Defenses Against DiseaseImmunities Protect against very specific pathogensAntigens Foreign substances in the bodyHaptensForeign substances too small to start an immune response by

16、 themselvesOther substancesProteins antibodies and complementsWBCs lymphocytes and macrophagesLymph systemCytokines assist in immune response regulationMonokines increase B cell production and stimulate WBC production28-19Defenses Against Disease (cont.)Two major types of lymphocytesB Cells and T Ce

17、llsRecognize antigens in the bodyT Cells Cell-mediated response Bind to antigens on cells and attack them directly Secrete lymphokines that increase T cell production and directly kill cells with antigensB cells Respond to antigens by becoming plasma cells Plasma cells make antibodies Memory B cells

18、 produce stronger response with next exposure to antigenDiagram28-20Back28-21Defenses Against Disease (cont.)T cell activation Begins when macrophage ingests and digests pathogen with antigen on itAntigens are placed on cell membrane of macrophage T cell recognizes and binds to antigen and the major

19、 histocompatibility complex (MHC) on the surface of the macrophageNow can divide to form other types of T cells28-22Defenses Against Disease (cont.)Types Cytotoxic T cellsProtect body against viruses and cancer cellsHelper T cellsIncrease antibody formation, memory cell formation, B cell formation,

20、and phagocytosisMemory T cellsRemember the pathogen that activated original T cellLater exposures trigger an immune response more effective than initial response28-23Defenses Against Disease (cont.)Natural killer (NK) cellsType of lymphocytePrimarily target cancer cellsKill on contactDo not recogniz

21、e a specific antigen28-24Apply Your KnowledgeIdentify 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 conta

22、ct_ Need macrophages and MHC for activation_ Make antibodies against specific antigenBNKTTTBNKANSWER:Right on Target!28-25AntibodiesAlso called immunoglobulins IgA Prevents pathogens from entering bodyIgD Found on B cell membranesThought to control B cell activityIgE Found with IgAInvolved in trigge

23、ring allergic reactions28-26Antibodies (cont.)IgGRecognizes bacteria, viruses, and toxinsActivates complementsIgM Large and binds to antigens on food, bacteria, or incompatible blood cellsActivates compliments28-27Antibodies (cont.)Actions that occur when antibodies bind to antigensAllow phagocytes

24、to recognize and destroy antigensCause antigens to clump together, causing them to be destroyed by macrophages Cover the toxic portions of antigens, making them harmlessActivate complement Group of proteins in serum that attack pathogens by forming holes in themAttract macrophages to pathogens and c

25、an stimulate inflammation28-28Apply Your KnowledgeWhat 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

26、cover the toxic portions of antigens to make them harmless. They activate complements. Very Good!28-29Immune Responses and Acquired ImmunityPrimary immune response occurs with first exposure to antigenSlow processMemory cells are formedSecondary immune response with next exposure to same antigenQuic

27、k and carried out by memory cellsUsually prevents person from developing disease from the antigen28-30Immune Responses and Acquired Immunity (cont.)Naturally acquired active immunityNatural exposure to antigen having an illnessMakes antibodies and memory cellsLong-lastingArtificially acquired active

28、 immunityInjected with pathogen immunizations or vaccinesMakes antibodies and memory cellsLong-lasting28-31Immune Responses and Acquired Immunity (cont.)Naturally acquired passive immunityAcquired from motherBreast milkPlacentaShort-livedArtificially acquired passive immunityInjected with antibodies

29、 (such as antivenom)Short-lived28-32Apply Your KnowledgeANSWER: 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. After you give an immunization to a 2-year-old

30、, her mother asks you why this will work to prevent her from getting a disease.Good Answer!28-33Major Immune System DisordersCancerUncontrolled growth of abnormal cells form malignant tumorsFactors known to cause cancer are called carcinogensTreatment based on stage0 very early; cancer cells localiz

31、edI spread to deeper layers or some in surrounding tissuesII spread to surrounding tissues but contained in primary siteIII spread beyond primary site into nearby areasIV spread to other organsRecurrent reappeared after treatment28-34Major Immune System Disorders (cont.)AllergiesImmune response to a

32、n allergenIgE antibodies bind to allergens and stimulate mast cells to release histamine and heparin, triggering allergic responseAllergy shotsSmall amounts of allergen stimulates production of IgG to prevent IgE from binding to antigen IgG antibodies do not stimulate mast cells, so immune response

33、is not generated28-35Major Immune System Disorders (cont.)Allergy signs/symptomsInhaled allergens runny nose, sneezing, coughing, wheezingIngested allergens nausea, vomiting, diarrheaSkin allergens rashesAllergens in blood most life-threatening; can affect many organsTreatmentAntihistamines, deconge

34、stants OTC or prescriptionEpinephrine for anaphylaxis vasoconstriction, increasing BPAnaphylaxis life-threatening response28-36Common Immune System Disorders Autoimmune diseaseBody attacks its own antigensExamples SclerodermaRheumatoid arthritisMultiple sclerosisGlomerulonephritisCrohns diseaseDiabe

35、tes mellitus, type I28-37Common Immune System Disorders (cont.)DisorderDescription AIDSDevelopment of severe signs and symptoms caused by HIV as it destroys lymphocytes; leaves immune system weakened and susceptible to other diseasesChronic fatigue syndrome (CFS)Condition of severe tiredness not rel

36、ieved by rest and not related to other illnessesLymphedemaBlockage of lymphatic vessels results in tissue swelling that increases over time28-38Common Immune System Disorders (cont.)DisorderDescription Mononucleosis“Mono”; highly contagious viral infection spread through saliva of infected personSys

37、temic lupus erythematous (SLE)Autoimmune disorder; produces antibodies that target own cells and tissues; affects women more often than men28-39Apply Your KnowledgeMatching:_ Immune response to a substanceA.CFS_ Blockage of lymphatic vesselsB.SLE_ “Kissing disease”C.Cancer_ “Butterfly” rash on faceD

38、.Autoimmune disease_ Severe tirednessE.Lymphedema_ Uncontrolled growth of abnormal cellsF.Mononucleosis_ Body attacks its own antigensG.AllergyGFEDCBAANSWER:Excellent!28-40In Summary28.1The lymph system is composed of pathways known as lymph vessels. In addition to the lymph vessels, the organs of t

39、he lymphatic system include lymph nodes located throughout the body, the thymus in the mediastinum, and the spleen located in the LUQ.28.2Lymph is the body fluid found between the bodys cells. It circulates through the body via lymphatic capillaries, lymphatic vessels, lymph nodes, lymphatic trunk,

40、collecting ducts, and to the subclavian vein.28-41In Summary (cont.)28.3Infection is the presence of a pathogen in or on the body. A pathogen is a disease-causing agent, and antigens are foreign substances within the body that may or may not cause disease.28.4The nonspecific body defenses include sp

41、ecies resistance, mechanical and chemical barriers, phagocytosis, fever, and inflammation.28.5Inflammation is the result of injury or infection. Signs are redness, heat, swelling, and pain.28-42In Summary (cont.)28.6Specific defenses are immunities or defenses against very specific antigens.28.7B an

42、d T cells come from the bone marrow, thymus, lymph nodes, spleen, and the lining of the digestive tract and are found circulating in the blood. B cells utilize memory and plasma cells in a process called humoral or antibody-mediated immunity, and T cells bind directly to cell antigens, attacking the

43、m directly, producing cell-mediated immunity.28-43In Summary (cont.)28.8 T cells cannot be activated to produce immunity without MHC proteins and macrophages.28.9Activated T cells may form cytotoxic cells which protect the body against viruses and certain types of cancer. Other T cells may become he

44、lper T cells, which increase antibody and memory cell and B cell formation and phagocytosis. Still other T cells become memory cells.28.10Antibodies may work in the following ways: phagocytosis, antigen clumping, covering (inactivating) toxic portions of antigens, and activating complements.28-44In

45、Summary (cont.)28.11Antibodies are also known as immunoglobulins. IgA prevents pathogens from entering the body; IgD controls B cell activity; IgE works with IgA in triggering allergic reactions; IgG recognizes bacteria, viruses and toxins and activates complements; and IgM binds to antigens on food

46、, bacteria, or incompatible blood cells. IgM also activates complements.28-45In Summary (cont.)28.12Complements are serum proteins that attack pathogens by forming holes in them. They also attract macrophages and can stimulate inflammation.28.13A primary immune response occurs the first time a perso

47、n is exposed to an antigen. The response is slow and takes several weeks to occur. A secondary immune response occurs at the next exposure. This response is very quick and may prevent the person from becoming ill.28-46In Summary (cont.)28.14The four types of immune response are natural active immunity, such as when someone becomes ill and develops immunity; artificial active immunity, as when an injection is given against a pathogen, preventing illness; natural passive immunity occurs when an infant has its mothers immunity for a short while af