1 PowerPoint ® to accompany Second Edition Ramutkowski  Booth  Pugh  Thompson  Whicker Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Medical Assisting Chapter 29

2 Objectives 29-1Spell, define, and correctly use the Key Terms in this chapter. 29-2Define the terms infection, pathogen, and antigen. 29-3List and describe the nonspecific body defense mechanisms. 29-4Explain the signs and causes of inflammation. 29-5Explain what is meant by specific body defenses. The Immune System

3 Objectives (cont.) 29-6Define B cells and T cells and describe their locations and functions. 29-7Explain the importance of MHC proteins. 29-8List the different types of T cells and describe their functions. 29-9List the different types of antibodies and tell how they differ Explain how antibodies fight infection Define complement and give its functions. The Immune System

Explain the difference between the primary immune response and secondary immune response Describe the function of a vaccine Explain the four different types of acquired immunities Describe how allergies develop. Objectives (cont.) The Immune System

Explain how the AIDS virus affects the immune system Identify the ways a person acquires AIDS Define cancer and carcinogen Explain how cancers are classified Describe how cancers are diagnosed and treated Describe the signs and symptoms of other common immune disorders. Objectives (cont.) The Immune System

6 Introduction Immune system - protects the body against  Bacteria  Viruses  Fungi  Toxins  Parasites  Cancer Click for Larger View

7 T and B Cell Activation

8 Defenses Against Disease Infection is the presence of a pathogen in or on the body Nonspecific defenses - mechanisms to protect us against pathogens in general Infection is the presence of a pathogen in or on the body Nonspecific defenses - mechanisms to protect us against pathogens in general Nonspecific Defenses  Species Resistance  Mechanical Barriers  Chemical Barriers  Fever  Inflammation  Phagocytosis

9 Specific Defenses Against Disease  Specific defenses are called immunities and protect the body against very specific pathogens  Lymphocytes and macrophages are the major white blood cells involved in specific defenses.  Antibodies and complement are the major proteins involved in specific defenses

10 Inflammation Signs:  Redness  Heat  Swelling  PainSigns:  Redness  Heat  Swelling  PainCauses:  Injured or infected with a pathogen, inflammation can resultCauses:

11 Apply Your Knowledge Your 18-year-old patient states that he thinks his right big toe is inflamed. What symptoms would you expect to see?

12 Answer Apply Your Knowledge - Answer Redness, heat, swelling, and pain Your 18-year-old patient states that he thinks his right big toe is inflamed. What symptoms would you expect to see?

13 B Cells & T Cells Two major types of lymphocytes B Cells and T Cells Recognize antigens in the body T Cells Cell-mediated bind to antigens on cells and attack them directly T Cells Cell-mediated bind to antigens on cells and attack them directly B cells Respond to antigens by becoming plasma cell - make antibodies against the specific antigen B cells Respond to antigens by becoming plasma cell - make antibodies against the specific antigen

14 Major Histocompatibility Complex (MHC)  Before a T cell can respond to an antigen, it must be activated  T cell activation begins when a macrophage ingests and digests a pathogen that has antigens  Macrophage then takes some of the antigens from the pathogen and puts them on its cell membrane next to a large protein complex (MHC)  T cells cannot be activated without macrophages and MHC proteins  Before a T cell can respond to an antigen, it must be activated  T cell activation begins when a macrophage ingests and digests a pathogen that has antigens  Macrophage then takes some of the antigens from the pathogen and puts them on its cell membrane next to a large protein complex (MHC)  T cells cannot be activated without macrophages and MHC proteins

15 T Cells Helper T cells  increase antibody formation, memory cell formation, B cell formation, and phagocytosis Memory T cells  memory cells “remember” the pathogen that activated the original T cell  person is later exposed to the same pathogen, memory cells trigger an immune response that is more effective than the first immune response Helper T cells  increase antibody formation, memory cell formation, B cell formation, and phagocytosis Memory T cells  memory cells “remember” the pathogen that activated the original T cell  person is later exposed to the same pathogen, memory cells trigger an immune response that is more effective than the first immune response

16 Antibodies  IgG - recognizes bacteria, viruses, and toxins. It can also activate complement.  IgA - found in secretions of the body such as breast milk, sweat, tears, saliva, and mucus-prevents pathogens from entering the body.  IgM - very large - primarily binds to antigens on food, bacteria, or incompatible blood cells- activates complement.  IgE - found wherever IgA is located- involved in triggering allergic reactions.

17 Antibodies Fight Infection  Allow phagocytes to recognize and destroy antigens.  Cause antigens to clump together which causes them to be destroyed by macrophages  Cover the toxic portions of antigens to make 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.  Allow phagocytes to recognize and destroy antigens.  Cause antigens to clump together which causes them to be destroyed by macrophages  Cover the toxic portions of antigens to make 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.

18 Immune Response  Primary immune response occurs the first time a person is exposed to an antigen  slow  takes several weeks to occur  memory cells are made  Secondary immune response occurs the next time a person is exposed to the same antigen  very quick  usually prevents a person from developing a disease from the antigen

19 Types of Immunity  Naturally acquired active - naturally exposed to an antigen - usually long lasting  Artificially acquired - active-being injected with a pathogen (immunizations or vaccines)  Naturally acquired passive - immunity through his mother - short-lived  Artificially acquired passive - immunity when he is injected with antibodies - short-lived

20 Apply Your Knowledge After you have give an immunization to a 2-year-old, her mother asks you why this will work to prevent her from getting a disease.

21 Answer Apply Your Knowledge - Answer Immunization is an artificially acquired immunity because a person develops this immunity by being injected with a pathogen and then subsequently making antibodies and memory cells against the pathogen. After you have give an immunization to a 2-year-old, her mother asks you why this will work to prevent her from getting a disease.

22 Major Immune System Disorders Diseases and disorders that challenge the immune system: (the following are the most significant)  HIV  Infections  AIDS  Cancer  Allergies

23 Acquired Immune Deficiency Syndrome (AIDS) Caused by human immunodeficiency virus (HIV) infection Most common routes of transmission are through sexual contact, blood, or from mother to child during pregnancy or breast-feeding. Caused by human immunodeficiency virus (HIV) infection Most common routes of transmission are through sexual contact, blood, or from mother to child during pregnancy or breast-feeding. Can have infection for years before developing any symptoms of this disease Less common routes of transmission are through accidental needle sticks, artificial insemination, and organ transplants.

24 Acquired Immune Deficiency Syndrome (AIDS) (cont.)  AIDS virus affects the immune system  Counts of CD4 cells are used to diagnose the stage of HIV infection. If below 200 patient has AIDS  AIDS virus affects the immune system  Counts of CD4 cells are used to diagnose the stage of HIV infection. If below 200 patient has AIDS  CD4 cells are types of T cells and are important for the functions of other components of the immune system.

25 Acquired Immune Deficiency Syndrome (AIDS) (cont.) HIV Testing:  The most sensitive test, and most expensive is called the polymerase chain reaction (PCR)  Determines the number of HIV particles in a sample of blood.  Useful in early diagnosis of HIV HIV Testing:  The most sensitive test, and most expensive is called the polymerase chain reaction (PCR)  Determines the number of HIV particles in a sample of blood.  Useful in early diagnosis of HIV

26 Acquired Immune Deficiency Syndrome (AIDS) (cont.) AIDS Testing:  ELISA – most commonly used test  Less expensive than PCR test but less reliable  Cannot detect early HIV infections  Counts of CD4 cells are used to diagnose the stage of HIV infection (CD4 cells are types of T cells) AIDS Testing:  ELISA – most commonly used test  Less expensive than PCR test but less reliable  Cannot detect early HIV infections  Counts of CD4 cells are used to diagnose the stage of HIV infection (CD4 cells are types of T cells)

27 Acquired Immune Deficiency Syndrome (AIDS) (cont.) Signs and Symptoms of AIDS:  Low T cell counts  Fever  Profuse sweating  Weakness  Weight loss  Swollen glands  Frequent infections  Some rare forms of cancer  A common form of cancer is called “Kaposi’s” sarcoma.

28 Apply Your Knowledge How can a patient contract HIV?

29 Answer Apply Your Knowledge - Answer Most common routes of transmission are through sexual contact, blood, or from mother to child during pregnancy or breast-feeding How can a patient contract HIV?

30 Cancer  Uncontrolled growth of abnormal cells  Cells often form growths called malignant tumors  200 different types of cancers are known  Carcinogen - factor that is known to cause the formation of cancer

31 Cancer (cont.)  The three most common forms of cancer:  Breast  Lung  Colon Lung cancer is the leading killer of all forms of cancer

32 Cancer Causes  Mostly unknown  Risk factors:  Suppressed immune system  Radiation  Tobacco  Prevention: Don’t smoke  A factor that is known to cause cancer is called a carcinogen.

33 Cancer Diagnosis  Biopsy - removal of tissues for examination  CT scans  Diagnostic tests  Blood counts  Analysis of blood chemistry  X rays

34 Cancer Treatment  Treatment differs depending on:  Type of cancer  Stage of cancer  Forms of treatment:  Surgically removing the tumor  Chemotherapy  Radiation therapy  Treatment differs depending on:  Type of cancer  Stage of cancer  Forms of treatment:  Surgically removing the tumor  Chemotherapy  Radiation therapy

35 Cancer Classifications Stage 0 Stage 0 - very early cancer. Cancer cells are localized in a few cell layers. Stage I Stage I - spread to deeper cell layers or some may have spread to surrounding tissues. Stage II Stage II - spread to surrounding tissues but is considered contained in the primary cancer site.

36 Cancer Classifications Stage III Stage III - spread beyond the primary cancer site to nearby areas. Stage IV Stage IV - spread to other organs of the body. Recurrent Recurrent - Cancer cells have reappeared after treatment.

37 Apply Your Knowledge Your patient has a stage III cancer. Explain what stage III means.

38 Answer Apply Your Knowledge - Answer Stage III means that the cancer has spread beyond the primary cancer site to nearby areas. Your patient has a stage III cancer. Explain what stage III means.

39 Allergies Allergic reaction is an immune response to a substance Allergens - trigger of allergic responses Allergic reaction is an immune response to a substance Allergens - trigger of allergic responses Anaphylaxis - blood vessels dilate quickly causing blood pressure to drop too quickly for organs to adjust. This condition is life threatening.

40 Allergies (cont.) Allergic reactions involve IgE antibodies and mast cells. IgE antibodies bind to allergens, they cause mast cells to release histamine and heparin These chemicals trigger allergic reactions. If a person is receiving allergy shots, he is being injected with tiny amounts of the allergen and reduces symptoms

41 Chronic fatigue syndrome Chronic fatigue syndrome - a condition in which a person feels severe tiredness that cannot be relieved by rest and cannot be related to another illness Signs and symptoms:  Severe fatigue  Mild fever  Sore throat  Tender lymph nodes in neck or armpit  General body aches Diseases and Disorders of the Immune System (cont.)

42 Lymphedema Lymphedema - blockage of lymphatic vessels, which are needed to drain excess fluids from areas of the body Signs:  Swelling that lasts longer than a few days  Swelling that increases over time Diseases and Disorders of the Immune System (cont.)

43 Lupus Lupus - an autoimmune disorder that affects few or many organ systems of the body Signs:  Arthritis  “Butterfly” rash on face  Sensitivity to sunlight  Renal failure  Headaches  Mental disorders Diseases and Disorders of the Immune System (cont.)

44 Rheumatoid arthritis Rheumatoid arthritis - an autoimmune disorder in which a person’s immune system attacks joints of the body Signs:  Fatigue  Joint pain  Swelling of joints – especially those in hands and feet  Body aches  Cartilage destruction Diseases and Disorders of the Immune System (cont.)

45 Apply Your Knowledge As you are taking your patient to the exam room, you notice that she has “Butterfly” rash on her face. What disorder exhibits this sign?

46 Answer Apply Your Knowledge - Answer Lupus As you are taking your patient to the exam room, you notice that she has “Butterfly” rash on her face. What disorder exhibits this sign?

47 Summary Medical Assistant Knowledge of the immune system will assist you in providing care for the patient with diseases and disorders of the immune system. You must have knowledge of this system when assisting the physician during the examination of a patient who is having problems with their immune system.

48 End of Chapter