CONCEPT QUESTIONS FOR EXAMINATION III - Biology 2420 Talaro & Chess, 9 th

Transcription

1 CONCEPT QUESTIONS FOR EXAMINATION III - Biology 2420 Talaro & Chess, 9 th Dr. Raj Ramakrishnan, Ph.D. NOTE: The topic sheets prepared by Dr. David Schwartz are being used by me with his kind permission. I have modified them in this document. DISCLAIMER: Topic sheets provide only general guidelines as to material which the student is assigned to learn. They are not contractual upon the instructor as to content or appearance of material on the examination, by weight or by difficulty. Read the chapter materials. Take some time to write answers to these questions. If you can answer them, you have a good grasp of the material! Chapter Differentiate between contamination, infection, and disease. What are the possible outcomes in each? 2. How are infectious diseases different from other diseases? 3. Name the general body areas that are sterile. Why is the inside of the intestine not sterile like many other organs? 4. What causes variations in the flora of the newborn intestine? 5. Explain several ways that true pathogens differ from opportunistic pathogens. 6. Distinguish between pathogenicity and virulence. Define virulence factors, and give examples of them in Gram-positive and Gram-negative bacteria, viruses, and parasites. 7. Describe the course of infection from contact with the pathogen to its exit from the host. 8. Explain why most microbes are limited to a single portal of entry. 9. For each portal of entry, give a vehicle that carries the pathogen and the course it must travel to invade the tissues. Explain how the portal of entry could differ from the site of infection. 10. Differentiate between exogenous and endogenous infections. 11. What factors possibly affect the size of the infectious dose? Name five factors involved in microbial adhesion. 12. Which body cells or tissues are affected by hemolysins, leukocidins, hyaluronidase, kinases, tetanus toxin, pertussis toxin, and enterotoxin? 13. Compare and contrast: systemic versus local infections; primary versus secondary infections; infection versus intoxication. 14. What is the difference between signs and symptoms? (First put yourself in the place of a patient with an infection and then in the place of a physician examining you. Describe what you would feel and what the physician would detect upon examining the affected area.) 15. What are some important considerations about the portal of exit? Name some examples of infections and their portals of exit. Page 1 of 6

2 16. Complete the table: Chemical make-up General source Degree of toxicity Effects on cells Symptoms in disease Examples Exotoxins Endotoxins Dr. Raj Ramakrishnan, Ph.D. 17. Outline the science of epidemiology and the work of an epidemiologist. 18. Using the following statistics, based on number of reported cases, can you determine which show endemic, sporadic, or epidemic patterns? How can you determine each type? Explain what would have to occur for these diseases to have a pandemic distribution. United States Region Disease Statistics Meningitis Northeast East Coast Central Southeast West Total cases Leprosy (Hansen s disease) Northeast 4 0 East Coast Central 7 8 Southeast West Total cases Cholera Northeast 2 1 East Coast 9 2 Central 6 2 Southeast 4 1 West 16 4 Total cases Distinguish between mechanical and biological vectors, giving one example of each. Page 2 of 6

3 Dr. Raj Ramakrishnan, Ph.D. 20. Explain what it means to be a carrier of infectious disease. Describe four ways that humans can be carriers. What is epidemiologically and medically important about carriers in the population? 21. Explain the precise difference between communicable and non-communicable infectious diseases. Between direct and indirect modes of transmission. Between vectors and vehicles as modes of transmission. 22. Nosocomial infections can arise from what two general sources? From this chapter list the major agents involved in nosocomial infections. Do they tend to be true pathogens or opportunists? Outline the two types of hospital asepsis and define isolation. What is the work of an infection control officer? 23. List the main features of Koch s postulates. Why is it so difficult to prove them for some diseases? 24. What is a fomite? What is a vehicle? What is the difference between a fomite and a vehicle? 25. What is epidemiology? What do epidemiologists do? Chapter Explain the functions of the three lines of defense. Which is the most essential to survival? What is the difference between nonspecific host defenses and immune responses? 2. Describe the main elements of the process through which the immune system distinguishes self from non-self. How is surveillance of the tissues carried out? What is responsible for it? What does the term foreign mean in reference to the immune system? Define the term antigen. 3. Trace the complete cycle of a bacterium through the immune compartments, starting with the blood, the RES, the lymphatics, and the ECF. (You will start and end at the same point.). What is the direct connection between the bloodstream and the lymphatic circulation? 4. Differentiate between granulocytes and agranulocytes. Describe the main cell types in each group, their functions, and their incidence in the circulation. 5. What is the principal function of lymphocytes? Differentiate between the two lymphocyte types and between humoral and cell-mediated immunity. 6.Why are platelets called formed elements? What are their functions? How are they associated with inflammation? 7. Explain the processes of diapedesis and chemotaxis, and show how they interrelate. 8. Differentiate between the terms pyogenic and pyrogenic. Use examples to explain the impact they have on the immune response. 9. Briefly account for the origins and actions of the major types of inflammatory mediators (cytokines). 10. What are the functions of macrophages? 11. Outline the major phases of phagocytosis. In what ways is a phagocyte a tiny container of disinfectants? 12. Briefly describe the three major types of interferon, their sources, and their biological effects. Describe the mechanism by which interferon acts as an antiviral compound. 13. Describe the general complement reaction in terms of a cascade. 14. What is the end result of complement activation? What are some other functions of complement components? 15. What is immunocompetence, immunologic specificity, and immunologic memory? Page 3 of 6

4 Dr. Raj Ramakrishnan, Ph.D. Chapters 15 &16 1. What function do receptors play in specific immune responses? How can receptors be made to vary so widely? 2. Describe the major histocompatibility complex, and explain how it participates in immune reactions. 3. Evaluate the following statement: (i) Each different lymphocyte type must have a unique receptor to react with antigen. (ii) How many different Ags might one be expected to meet up with during life? 4. What constitutes a clone of lymphocytes? Explain the clonal selection theory of antibody specificity and diversity. During development, when is antigen not needed, and why is it not needed? When is antigen needed? Why must the body develop tolerance to self? 5. Trace the origin and development of B lymphocytes; of T lymphocytes. What is happening during lymphocyte maturation? 6. Describe three ways that B cells and T cells are similar and at least five major ways in which they are different. 7. What is an antigen or immunogen? What is the antigenic determinant? 8. How do foreignness, size, and complexity contribute to antigenicity? What is a mosaic antigen? Why are haptens by themselves not antigenic, even though foreign? How can they be made to behave as antigens? 9. Differentiate among autoantigens, alloantigens, and heterophile antigens. Explain briefly what importance each has in immune reactions. 10. Describe the actions of an antigen-processing cell. What is the difference between a T-celldependent and T-cell-independent response? 11. Trace the immune response system, beginning with the entry of a T-cell-dependent antigen, antigen processing, presentation, the cooperative response among the macrophage and lymphocytes, and the reactions of activated B and T cells. 12. On what basis is a particular B-cell clone selected? What happens when B cells are activated? What are the functions of plasma cells, clonal expansion, and memory cells? 13. Describe the structure of immunoglobulin. What are the functions of the Fab and Fc portions? Describe four or five ways that antibodies function in immunity. Describe the attachment of Abs to Ags. (What eventually happens to the Ags?) 14. Contrast the primary and secondary response to Ag. Explain the type, order of appearance, and amount of immunoglobulin in each response and the reasons for them. 15. What causes the latent period? The anamnestic response? Explain how monoclonal and polyclonal antibodies are different. Outline the basic steps in production of monoclonal antibodies. Describe several possible applications of monoclonals in medicine. 16. Why are the immunities involving T cells called cell-mediated? How do T cells become sensitized? 17. Summarize the function of each category of T cell and the types of receptors with which they are associated. Define cytokines, and provide some examples of them. How do cytotoxic cells kill their target? 18. Why would the immune system naturally require suppression? 19. What is a natural killer cell, and what are its functions? 20. Contrast active and passive immunity in terms of how each is acquired, how long it lasts, whether memory is triggered, how soon it becomes effective, and what immune cells and substances are involved. Name at least two major ways that natural and artificial immunities are different. 21. Multiple matching (summarizes information from chapters 14 and 15). In the blanks on the left place the letters of all of the host defenses and immune responses in the right column that can fit the description. Page 4 of 6

5 vaccination for tetanus lysozyme in tears immunization with horse serum in utero transfer of antibodies booster injection for diphtheria recovery from a case of mumps colostrum interferon action of neutophils injection of gamma globulin recovery from a case of mumps edema humans having protection from canine distemper virus stomach acid cilia in trachea asymptomatic chickenpox complement a. active b. passive c. natural d. artificial e. acquired f. innate, inborn g. chemical barrier h. mechanical barrier i. genetic barrier j. specific k. nonspecific l. inflammatory response m. second line of defense n. none of these Dr. Raj Ramakrishnan, Ph.D. 22. Name three products used in passive artificial immunization. What are the primary reasons for using these substances? What are some disadvantages of this form of immunization? What is the difference between immunization used for prophylaxis and that used for treatment? 23. Outline the strategies for developing vaccines, and give specific examples for each method. By what means are microorganisms attenuated? What is the purpose of an adjuvant? Describe the way that a Trojan horse vaccine works. 24. What are the advantages and disadvantages of a killed vaccine; a live, attenuated vaccine; a subunit vaccine; a recombinant vaccine; and a DNA vaccine? Use an outline to explain how an inoculation with tetanus toxoid will protect a person the next time he or she steps on a dirty piece of glass. 25. Describe the concept of herd immunity. How does vaccination contribute to its development in a community? Give some possible explanations for the recent epidemics of diphtheria and whooping cough. 26. What is the basis of serology and serological testing? Differentiate between specificity and sensitivity. 27. What does seropositivity mean? In what ways is the antibody titer of serum important? What causes false positive tests? 28. What is meant by complement fixation? What are cytolysins? What is the purpose of using sheep red blood cells in this test? Page 5 of 6

6 Dr. Raj Ramakrishnan, Ph.D. 29. Briefly describe the principles and give an example of the use of a specific test using immunoelectrophoresis, Western blot, complement fixation, fluorescence testing (direct and indirect), and immunoassays (direct and indirect ELISA). Explain a rapid microscopic method for differentiating T cells from B cells. 30. What is the definition of toxin, toxoid, antitoxin? 31. Which antibodies predominate in the secondary response? Know all protective functions that antibodies perform. 32. Which antibody crosses the placenta to protect or to harm the fetus? (Hint: It is the most abundant antibody in plasma.) 33. What is erythroblastosis fetalis? Why does it occur? Can it be prevented? What is RhoGam and its role? 34. BE ABLE TO USE THE MEDICAL, MICROBIOLOGICAL, IMMUNOLOGICAL AND EPIDEMIOLOGICAL PRINCIPLES AND INFORMATION IN ALL OF UNIT III TO ADVISE A YOUNG PARENT ABOUT VACCINATION OF A CHILD. BE SURE TO KNOW WHAT VACCINATION IS AND HOW IT WORKS, WHAT BOOSTER SHOTS ARE AND HOW THEY WORK, AND AT LEAST FIVE CHILDHOOD DISEASES THAT CAN BE PREVENTED BY VACCINATION. In addition, you are responsible for all specialized microbiological vocabulary not mentioned in this general review. If I use a specialized word in a question or in any answer, and that term was used in class, or in any of your reading assignments, I will expect you to know the meaning of it. This holds for all exams, not just this one. Page 6 of 6