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

1、CHAPTER 2011 The McGraw-Hill Companies, Inc. All rights reserved.28The Lymphatic and Immune Systems 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-2Learning Outcomes28.1List the pathways and organs of the lymphatic system and give their locations.28.2Define lymph and tell how it is circ

2、ulated in the body.28.3Define the terms infection, pathogen, and antigen.28.4List and describe the nonspecific body defense mechanisms.28.5Explain the signs and causes of inflammation. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-3Learning Outcomes (cont.)28.6Explain what is meant by

3、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 describe their functions.28.10 Explain how antibodies fight infection. 2011 The McGraw-Hill Companies, Inc. All rights rese

4、rved.28-4Learning Outcomes (cont.)28.11 List the different types of antibodies and tell how they differ.28.12 Define complement proteins and give their function.28.13 Explain the difference between the primary immune response and secondary immune response.28.14 Explain the four different types of ac

5、quired immunities.28.15 Describe the function of a vaccine. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-5Learning Outcomes (cont.)28.16 Define the terms cancer and carcinogen.28.17 Describe how cancers are diagnosed and treated.28.18 Explain how cancers are classified.28.19 Describe

6、how allergies develop.28.20 Describe the causes, signs and symptoms, and treatments of other common immune disorders. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-6Introduction Immune system Protects the body against Bacteria Viruses Fungi Toxins Parasites Cancer Lymphatic system Work

7、s with immune system to remove disease-causing agents Organs Thymus Spleen Lymph nodes 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-7The Lymphatic System Network of connecting vessels Collects fluid (lymph) between cells and returns it to bloodstream Picks up lipids from digestive org

8、ans and transports them to bloodstream Functions to defend the body against pathogens 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-8Lymphatic Pathways Lymphatic capillaries Extend into interstitial spaces Permeable, thin walls pick up fluid, now lymph Delivers lymph to lymphatic vesse

9、ls 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 vesselsLymph System 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-9Lymphatic Pathways (cont.) Lymphatic trunks Receive l

10、ymph 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 chestLymph System 2011 The M

11、cGraw-Hill Companies, Inc. All rights reserved.28-10Tissue 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

12、squeezing action of neighboring skeletal muscles and breathing movement 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-11Back 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-12Lymph Nodes Small, glandular structures Located along paths of larger lymphatic vessels Afferent ly

13、mphatic vessels Lymph to node Efferent lymphatic vessels Lymph from node 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-13Lymph Nodes (cont.) More lymph enters than can leave at one time Cells in nodes Macrophages digest unwanted pathogens Lymphocytes start an immune response against pa

14、thogen Nodes can generate some lymphocytes 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-14The Thymus and Spleen 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 Prod

15、uces thymosin stimulates production of lymphocytes 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-15The Thymus and Spleen (cont.) Spleen Largest lymphatic organ Located in the upper left quadrant of abdominal cavity Functions Filters blood similarly to lymph nodes Removes worn-out red c

16、ells If removed (splenectomy), liver takes over most of its function 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-16Apply 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 th

17、e 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. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-17Defenses Against Disease In

18、fection 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 2011 The McGraw-Hill Companies, Inc. A

19、ll rights reserved.28-18Specific 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 an

20、d macrophages Lymph system Cytokines assist in immune response regulation Monokines increase B cell production and stimulate WBC production 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-19Defenses Against Disease (cont.)Two major types of lymphocytesB Cells and T CellsRecognize antigen

21、s in the bodyT Cells v Cell-mediated responsev Bind to antigens on cells and attack them directly v Secrete lymphokines that increase T cell production and directly kill cells with antigensB cells v Respond to antigens by becoming plasma cellsv Plasma cells make antibodiesv Memory B cells produce st

22、ronger response with next exposure to antigenDiagram 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-20Back 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-21Defenses Against Disease (cont.) T cell activation Begins when macrophage ingests and digests pathogen with antigen on

23、 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 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-22Defenses Against D

24、isease (cont.) 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 mo

25、re effective than initial response 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-23Defenses Against Disease (cont.) Natural killer (NK) cells Type of lymphocyte Primarily target cancer cells Kill on contact Do not recognize a specific antigen 2011 The McGraw-Hill Companies, Inc. All ri

26、ghts reserved.28-24Apply 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 contact_ Ne

27、ed macrophages and MHC for activation_ Make antibodies against specific antigenBNKTTTBNKANSWER:Right on Target! 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-25Antibodies Also called immunoglobulins IgA Prevents pathogens from entering bodyIgD Found on B cell membranes Thought to contr

28、ol B cell activityIgE Found with IgA Involved in triggering allergic reactions 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-26Antibodies (cont.)IgG Recognizes bacteria, viruses, and toxins Activates complementsIgM Large and binds to antigens on food, bacteria, or incompatible blood ce

29、lls Activates compliments 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-27Antibodies (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 to

30、xic 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 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-28Apply Your KnowledgeWhat are the

31、possible actions that occur when antibodies bind to antigens?ANSWER: Possible actions include:v They allow phagocytes to recognize and destroy antigens. v They make antigens clump together, causing them to be destroyed by macrophages. v They cover the toxic portions of antigens to make them harmless

32、.v They activate complements. Very Good! 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-29Immune 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 antige

33、n Quick and carried out by memory cells Usually prevents person from developing disease from the antigen 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-30Immune Responses and Acquired Immunity (cont.) Naturally acquired active immunity Natural exposure to antigen having an illness Makes

34、 antibodies and memory cells Long-lasting Artificially acquired active immunity Injected with pathogen immunizations or vaccines Makes antibodies and memory cells Long-lasting 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-31Immune Responses and Acquired Immunity (cont.) Naturally acqui

35、red passive immunity Acquired from mother Breast milk Placenta Short-lived Artificially acquired passive immunity Injected with antibodies (such as antivenom) Short-lived 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-32Apply Your KnowledgeANSWER: Immunization is an artificially acquire

36、d 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, her mother asks you why this will work to prevent her from getting a disease. 2011 The McGraw-Hill Co

37、mpanies, Inc. All rights reserved.28-33Major Immune System Disorders Cancer Uncontrolled growth of abnormal cells form malignant tumors Factors known to cause cancer are called carcinogens Treatment based on stage0 very early; cancer cells localizedI spread to deeper layers or some in surrounding ti

38、ssuesII spread to surrounding tissues but contained in primary siteIII spread beyond primary site into nearby areasIV spread to other organsRecurrent reappeared after treatment 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-34Major Immune System Disorders (cont.) Allergies Immune respon

39、se to an allergen IgE antibodies bind to allergens and stimulate mast cells to release histamine and heparin, triggering 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

40、 response is not generated 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-35Major Immune System Disorders (cont.) Allergy signs/symptoms Inhaled allergens runny nose, sneezing, coughing, wheezing Ingested allergens nausea, vomiting, diarrhea Skin allergens rashes Allergens in blood most

41、 life-threatening; can affect many organs Treatment Antihistamines, decongestants OTC or prescription Epinephrine for anaphylaxis vasoconstriction, increasing BP Anaphylaxis life-threatening response 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-36Common Immune System Disorders Autoimm

42、une disease Body attacks its own antigens Examples Scleroderma Rheumatoid arthritis Multiple sclerosis Glomerulonephritis Crohns disease Diabetes mellitus, type I 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-37Common Immune System Disorders (cont.)DisorderDescription AIDSDevelopment o

43、f 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 relieved by rest and not related to other illnessesLymphedemaBlockage of lymphatic vessels results in t

44、issue swelling that increases over time 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-38Common Immune System Disorders (cont.)DisorderDescription Mononucleosis“Mono”; highly contagious viral infection spread through saliva of infected personSystemic lupus erythematous (SLE)Autoimmune d

45、isorder; produces antibodies that target own cells and tissues; affects women more often than men 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-39Apply Your KnowledgeMatching:_ Immune response to a substanceA. CFS_ Blockage of lymphatic vesselsB. SLE_ “Kissing diseaseC. Cancer_ “Butter

46、fly rash on faceD. Autoimmune disease_ Severe tirednessE. Lymphedema_ Uncontrolled growth of abnormal cellsF. Mononucleosis_ Body attacks its own antigensG. AllergyGFEDCBAANSWER: 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-40In Summary28.1 The lymph system is composed of pathways kno

47、wn as lymph vessels. In addition to the lymph vessels, the organs of the lymphatic system include lymph nodes located throughout the body, the thymus in the mediastinum, and the spleen located in the LUQ.28.2 Lymph is the body fluid found between the bodys cells. It circulates through the body via l

48、ymphatic capillaries, lymphatic vessels, lymph nodes, lymphatic trunk, collecting ducts, and to the subclavian vein. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-41In Summary (cont.)28.3 Infection is the presence of a pathogen in or on the body. A pathogen is a disease-causing agent,

49、and antigens are foreign substances within the body that may or may not cause disease. 28.4 The nonspecific body defenses include species resistance, mechanical and chemical barriers, phagocytosis, fever, and inflammation.28.5 Inflammation is the result of injury or infection. Signs are redness, hea

50、t, swelling, and pain. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-42In Summary (cont.)28.6 Specific defenses are immunities or defenses against very specific antigens.28.7 B and T cells come from the bone marrow, thymus, lymph nodes, spleen, and the lining of the digestive tract and

51、 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 them directly, producing cell-mediated immunity. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-4

52、3In 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 helper T cells, which increase antibody and memory

53、cell and B cell formation and phagocytosis. Still other T cells become memory cells.28.10 Antibodies may work in the following ways: phagocytosis, antigen clumping, covering (inactivating) toxic portions of antigens, and activating complements. 2011 The McGraw-Hill Companies, Inc. All rights reserve

54、d.28-44In Summary (cont.)28.11 Antibodies 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 antig

55、ens on food, bacteria, or incompatible blood cells. IgM also activates complements. 2011 The McGraw-Hill Companies, Inc. All rights reserved.28-45In Summary (cont.)28.12 Complements are serum proteins that attack pathogens by forming holes in them. They also attract macrophages and can stimulate inf

56、lammation.28.13 A primary immune response occurs the first time a person 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. 2011 The McGraw

57、-Hill Companies, Inc. All rights reserved.28-46In Summary (cont.)28.14 The 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 immuni