Defense Mechanisms of the Body
1. What are the major cells of the immune system and their
2. Describe the major anatomical and biochemical barriers to
3. Name the three cell types that function as phagocytes.
4. List the sequence of events in an inﬂ ammatory response and
describe each step.
5. Name the sources of the major inﬂ
6. What triggers the alternate pathway for complement activation?
What roles does complement play in inﬂ ammation and cell
7. Describe the antiviral role of interferon.
8. Name the lymphoid organs. Contrast the functions of the
bone marrow and thymus with those of the secondary
9. Name the various populations and subpopulations of
lymphocytes and discuss their roles in speciﬁ c immune responses.
10. Contrast the major targets of antibody-mediated responses and
responses mediated by cytotoxic T cells and NK cells.
11. How do the Fc and combining-site portions of antibodies
12. What are the differences between B-cell receptors and T-cell
receptors? Between cytotoxic T-cell receptors and helper T-cell
13. Compare and contrast antigen presentation to helper T cells
and cytotoxic T cells.
14. Compare and contrast cytotoxic T cells and NK cells.
15. What two processes contribute to immune tolerance?
16. Diagram the sequence of events in an antibody-mediated
response, including the role of helper T cells, interleukin 1, and
17. Contrast the general functions of the different antibody
18. How is complement activation triggered in the classical
complement pathway, and how does complement “know” what
cells to attack?
19. Name two ways in which the presence of antibodies enhances
20. How do NK cells “know” which cells to attack in ADCC?
21. Diagram the sequence of events by which a virus-infected cell
is attacked and destroyed by cytotoxic T cells. Include the
roles of cytotoxic T cells, helper T cells, interleukin 1, and
22. Contrast the extracellular and intracellular phases of immune
responses to viruses, discussing the role of interferon.
23. List the systemic responses to infection or injury and the
mediators responsible for them.
24. What factors inﬂ uence the body’s resistance to infection?
25. What is the major defect in AIDS, and what causes it?
26. What is the major cell type involved in graft rejection?
27. Diagram the sequences of events in immediate hypersensitivity.
(Because of the subject matter of this chapter, it is difﬁ
distinguish between “physiological” key terms and “clinical” terms.
This list is limited largely to disease-producing agents and disease
acquired immune deﬁ ciency
butterﬂ y rash
hemolytic disease of the
human immunodeﬁ ciency virus
inﬂ ammatory bowel
Type 1 diabetes mellitus
Chapter 18 Test Questions
(Answers appear in Appendix A.)
1. Which of the following is an opsonin?
b. C1 protein
c. C3b protein
d. C-reactive protein
e. membrane attack complex
2. Which are important in nonspeciﬁ c immune defenses?
b. clonal inactivation
c. lymphocyte activation
d. secretion of antibodies from plasma cells
e. class 1 MHC proteins
3. A second exposure to a given foreign antigen elicits a rapid and
pronounced immune response because
a. passive immunity occurs after the ﬁ rst exposure.
b. some B cells differentiate into memory B cells after the ﬁ rst
c. there are a greater number of antigen-presenting cells
available due to the earlier exposure.
d. the array of class II MHC proteins expressed by antigen-
presenting cells is permanently altered by the ﬁ rst exposure.
e. Both a and b are correct.