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DEFENSES AGAINST DISEASE
CHAPTER REVIEW
The immune system consists of lymphatic organs, tissues,
and cells, as well as the products of these cells. The lymphatic organs are red bone marrow, thymus, lymph nodes,
and the spleen. Patches of lymphatic tissue include the
tonsils and appendix. Defense against foreign substances,
pathogens, and cancer cells occurs on two fronts: nonspecific
defenses and specific defenses. Nonspecific defenses
occur first and consist of barriers to entry, the inflammatory response, the complement system, and natural
killer cells. Specific defenses are dependent on lymphocytes (B and T cells), each of which is specific for just
one antigen. An antigen is a molecule, which provokes
an immune response. B cells produce antibodies against
an antigen and T cells either coordinate the specific response (helper T cells) or they kill cells that bear a particular antigen (cytotoxic T cells.)
Modern medicine is sometimes able to produce vaccines, which are antigens changed in such a way that they
provoke a specific immune response without causing disease. The immune system falters when someone has allergies, an autoimmune disease, or has AIDS. AIDS is caused
by HIV, a virus which kills helper T cells.
CHAPTER KEY TERMS
After studying the key terms of this chapter, match the phrases below with the alphabetized list of terms.
active immunity
complement system
agglutination
cytokine
allergy
histamine
antibody
immune system
antigen
immunity
antigen-presenting cell
passive immunity
autoimmune disease
vaccine
a. cell that displays the antigen to certain cells of the immune system so they can defend the body
_______________________
b. type of protein secreted by a T cell that stimulates cells of the immune system _______________________
c. ability of the body to protect itself from foreign substances and cells _______________________
d. antigens prepared in such a way that they can promote active immunity without causing disease
_______________________
e. resistance to a disease due to immune system’s response to a microorganism or vaccine _______________________
f. immune response to substances that usually are not recognized as foreign _______________________
g. group of plasma proteins that form a nonspecific defense mechanism _______________________
h. all the organs and cells in the body that protect the body against foreign organisms and substances
_______________________
i. clumping of red blood cells due to an antigen antibody reaction _______________________
j. foreign substance that stimulates the immune system to react _______________________
k. protection against infection acquired by transfer of antibodies to a susceptible individual _______________________
l. protein produced in response to the presence of an antigen _______________________
m. substance, produced by mast cells, that causes capillaries to dilate _______________________
n. disease that results when the immune system mistakenly attacks the body’s own tissues _______________________
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S T U DY E X E R C I S E S
Study the text section by section as you answer the questions that follow.
26.1 ORGANS,TISSUES, AND CELLS
(PP. 456–457)
OF THE
IMMUNE SYSTEM
• Lymphocytes and other white blood cells are produced in the red bone marrow and mature there except for the
T lymphocytes, which mature in the thymus gland.
• Lymphocytes proliferate and congregate in the lymph nodes and spleen. The tonsils and appendix are patches
of lymphatic tissue.
1. Place the appropriate letter(s) next to each statement:
T— thymus
marrow
a.
b.
c.
d.
e.
f.
S—spleen
RBM—red bone
contains red pulp and white pulp
contains stem cells for white blood
cells
is located along the trachea
is located in the upper left abdominal
cavity
produces hormones believed to
stimulate the immune system
site of origin for all types of blood
cells
2. Study the table on the right and answer the
questions.
a. Which two white blood cells phagocytize
pathogens? ____________________________
b. Which type of white blood cell is
responsible for specific immunity?
c. B cells produce which two types of cells
and what are their functions? ____________
Table 26.1
Cell
Function
Macrophages
Phagocytize pathogens;
inflammatory response and
specific immunity
Mast cells
Release histamine, which promotes
blood flow to injured tissues;
inflammatory response
Neutrophils
Phagocytize pathogens;
inflammatory response
Natural killer cells
Kill virus-infected and tumor cells
by cell-to-cell contact
Lymphocytes
Responsible for specific immunity
B cells
Produce plasma cells and
memory cells
Plasma cells
Produce specific antibodies
Memory cells
Ready to produce antibodies in
the future
T cells
d. Which two types of cells can kill cancer
cells?
e. Which type of cell coordinates immunity?
Immunocell Type
and Function
Regulate immune response;
produce cytotoxic T cells and
helper T cells
Cytotoxic T cells
Kill virus-infected and cancer cells
Helper T cells
Regulate immunity
26.2 NONSPECIFIC DEFENSES (PP. 458–459)
• Nonspecific defenses include barriers to entry, the inflammatory response, the complement system, and
natural killer cells.
• In the inflammatory response, the area swells and becomes red, warm, and painful. In particular, neutrophils
and macrophages phagocytize pathogens.
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3. Match the descriptions to these nonspecific defense mechanisms:
1. barrier to entry
4. phagocytes
a.
b.
c.
d.
e.
f.
g.
h.
i.
2. inflammatory reaction
3. complement system
5. natural killer cells
accompanied by swelling and redness
cilia action in the respiratory tract
produces holes in bacterial cell walls
stomach secretions
histamine increases capillary permeability
vagina is inhabited by nonpathogenic bacteria
neutrophils and macrophages carry out phagocytosis
secretions of the oil, or sebaceous, glands
kills cells infected with a virus and tumor cells
4. Label the adjacent
diagram and answer the
questions using the labels:
c.
b.
a.
d.
e.
g.
f.
h.
i.
j.
k.
Inflamed area is red and warm; increased blood flow in the _______________________.
Inflamed area is experiencing swelling and pain. Escape of _______________________.
The cell releases histamine. _______________________
Viruses and bacteria are _______________________.
26.3 SPECIFIC DEFENSES (PP. 460–463)
B CELLS
AND THE
ANTIBODY RESPONSE (PP. 460–461)
• When a B-cell receptor binds to an antigen, the B cell divides and forms antibody-secreting plasma cells and
memory B cells.
5. Which of these correctly describes the B cell receptor?
a.
can respond to any antigen
b.
can respond to only one specific antigen
6. Which of these correctly describes what happens to B cells after activation?
a.
divides, producing many plasma cells and many memory cells
b.
goes on to kill cells on contact
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7. Which of these cells does nothing at present but may be called upon to produce antibodies in the future?
a.
plasma cell
b.
memory B cell
8. Complete the sentence about B cells.
a. B cells provide an ____________________ response to a pathogen.
b. B cells are produced and mature in ____________________.
c. Cell division produces antibody-secreting ____________________ cells.
9. Label the adjacent diagram of an antibody molecule:
c. What is the function of antibodies?
a.
______________________________
______________________________
______________________________
b.
10. The following table indicates the blood types. Fill in the fourth and fifth columns by using this formula: The
donor’s antigen(s) must not be of the same type as the recipients antibody (antibodies).
Blood Type
Antigen
Antibody
Can Receive from
Can Donate to
A
A
Anti-B
a.
b.
B
B
Anti-A
c.
d.
AB
A, B
______
e.
f.
O
None
Anti-A and B
g.
h.
T CELLS
AND THE
CELLULAR RESPONSE (PP. 462–463)
• When a T-cell receptor binds to an antigen displayed on the surface of a macrophage, the T cell becomes a
cytotoxic T cell (kills virus-infected or cancer cells) or a helper T cell (produces cytokines).
11. Which of these makes a particular T cell undergo clonal expansion?
a.
when the antigen is presented to the T cells by an APC
b.
when a T cell encounters an antigen
12. a. What happens after a helper T cell is able to recognize an antigen? ___________________________________
_______________________________________________________________________________________________
b. What happens after a cytotoxic T cell is able to recognize an antigen? _________________________________
_______________________________________________________________________________________________
c. What is the function of perforin (P) and granzymes (G)? _____________________________________________
_______________________________________________________________________________________________
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13. Place the appropriate letter(s) next to each statement:
B—B cell
a.
b.
c.
d.
e.
f.
g.
h.
i.
T—T cell
mature in bone marrow
mature in thymus
antibody-mediated immunity
cell-mediated immunity
Cytotoxic T cells destroy antigen-bearing cells.
directly recognize antigen
secrete cytokines
Clonal expansion produces antibody-secreting plasma cells as well as memory cells.
antigen presented with a MHC protein
14. Complete the sentence about T cells.
a. T cells provide a ____________________ response to virus-infected cells and cancer cells.
b. T cells are produced in ____________________ and mature in the ____________________ gland.
c. Antigen must be presented in the groove of an ____________________ molecule.
d. Cytotoxic T cells kill ____________________ cells.
e. Helper T cells secrete ____________________ that control the immune response.
26.4 IMMUNIZATIONS (P. 464)
• Injections of vaccines also result in immunity to a particular disease.
15. Label the following diagram using the alphabetized list of terms:
first exposure to vaccine
secondary response
plasma antibody concentration
second exposure to vaccine
b.
primary response
c.
e.
a.
d.
0
30
60
90
120
150
180
f. A good secondary response can be related to the number of _______________________ cells capable of
responding to the particular antigen.
16. Passive immunity can be provided by giving a person a portion of someone’s blood called gamma globulin.
What’s in gamma globulin? ________________________________________________________________________
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26.5 IMMUNE SYSTEM PROBLEMS (PP. 465–466)
• In allergic responses, the body responds to allergens to which most people do not respond.
• In autoimmune diseases, such as rheumatoid arthritis, the immune system mistakenly attacks the body’s own
tissues.
• AIDS is caused by an HIV infection of helper T cells in particular. In the untreated individual, the number of
T cells declines, and the occurrence of infections increases until death occurs.
17. Relate the immune response to each of these:
a. allergy
b. tissue rejection
c. autoimmune disease
HIV in Plasma (per ml)
Helper T Cells in Blood (per mm3)
18. Study the following diagram and answer the questions:
Helper T cells
HIV
0
1
2
3
4
5
6
Years
7
8
9
10
a. What happens once the HIV infection takes hold? Why?
b. Untreated, a person with an HIV infection dies from infections other than the HIV infection. Why?
19. What are the two ways to get an HIV infection? _______________________________________________________
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D E F I N I T I O N S WO R D S E A R C H
Review key terms by using the following alphabetized list of terms to fill in the blanks, and complete the wordsearch:
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antibody
appendix
autoimmune
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macrophage
neutrophil
spleen
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a. _______________
First leukocyte to respond to an infection.
b. _______________
A system of plasma proteins that are a nonspecific defense.
c. _______________
A disease caused by the immune system attacking the person’s own body.
d. _______________
Organ in abdomen that stores and purifies blood.
e. _______________
Type of protein secreted by a T cell that stimulates cells of the immune system.
f. _______________
Large phagocytic cell.
g. _______________
Lymphatic gland that secretes hormones, which aid the maturation of T cells.
h. _______________
A protein produced by B cells in response to foreign antigens.
i. _______________
Substance produced by mast cells in an allergic reaction.
j. _______________
Small, tubular appendage that extends outward from the cecum of the large intestine.
CHAPTER TEST
OBJECTIVE QUESTIONS
Do not refer to the text when taking this test.
1. Which of these is mismatched?
a. B cell—divides
b. plasma cell—secretes antibodies
c. memory cell—can produce antibodies in the
future
d. All of these are matched correctly.
2. Which of these is not characteristic of T cells?
a. produce antibodies
b. occur as cytotoxic T cells and helper T cells
c. kill cells by releasing perforin and granzymes
d. occur as more than one type
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3. Which one does not occur when an APC presents
the antigen?
a. The antigen is placed in the groove of an MHC.
b. The macrophage is destroyed in the process.
c. Cytokines stimulate the process.
d. T cells are activated.
In questions 4–7, match the descriptions to these terms:
a. thymus gland b. spleen
c. lymph node d. red bone marrow
4.
5.
6.
7.
causes maturation of T cells
purifies lymph
purifies blood
formation of white blood cells
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8. The spleen
a. contains stem cells from the bone marrow.
b. is located along the trachea.
c. produces a hormone believed to stimulate the
immune system.
d. contains red pulp and white pulp.
9. The thymus
a. contains all types of stem cells from the bone
marrow.
b. is located along the trachea.
c. produces a hormone believed to stimulate the
immune system.
d. Both b and c are correct.
10. Activity of the complement system is an example of nonspecific defense by
a. barriers to entry.
b. phagocytic cells.
c. protective proteins.
d. Both a and c are correct.
11. Secretions of the oil glands are an example of
nonspecific defense by a(n)
a. barrier to entry.
b. protective protein.
c. phagocytic cell.
d. acidic pH.
12. The most active white blood cell phagocytes are
a. neutrophils and macrophages.
b. neutrophils and eosinophils.
c. lymphocytes and macrophages.
d. lymphocytes and neutrophils.
13. The white blood cells primarily responsible for
specific immunity are
a. neutrophils.
b. eosinophils.
c. macrophages.
d. lymphocytes.
14. Which of these is NOT a valid contrast between
T cells and B cells?
T cells
B cells
a. mature in the thymus/mature in bone marrow
b. antibody-mediated immunity/cell-mediated
immunity
c. antigen must be presented by APC/direct recognition
d. cytokines/do not produce cytokines
15. A particular antibody can
a. attack any type of antigen.
b. attack only a specific type of antigen.
c. be produced by any B lymphocyte.
d. be produced by any T lymphocyte.
16. The portions of an antibody molecule that pair
up with the foreign antigens are the
a. heavy chains.
b. light chains.
c. variable regions.
d. constant regions.
17. Which of these pairs is incorrect?
a. helper T cells—orchestrate the immune response
b. cytotoxic T cells—stimulate B cells to produce antibodies
c. memory T cells—long-lasting active immunity
d. suppressor T cells—shut down the immune
response
18. A person receiving an injection of gamma globulin
as a protection against hepatitis is an example of
a. naturally acquired active immunity.
b. naturally acquired passive immunity.
c. artificially acquired passive immunity.
d. artificially acquired active immunity.
19. Allergies are caused by
a. strong toxins in the environment.
b. autoimmune diseases.
c. reaction to an antigen.
d. the receipt of IgA in breast milk.
20. Which is NOT true of an autoimmune response?
a. responsible for such diseases as multiple sclerosis and myasthenia gravis and perhaps type 1
diabetes
b. occurs when self-antibodies attack self-tissues
c. interferes with the transplantation of organs
between one person and another
d. All of these are true.
21. Why can’t you give A type blood to a person
with B type blood?
a. Anti-A antibodies in the plasma combine with
B antigens on the donated red blood cells.
b. Agglutination occurs.
c. T cells destroy the donated blood cells.
d. Both a and b are correct.
CRITICAL THINKING QUESTIONS
The introduction to this chapter is about body temperature and fighting infection.
22. Fever (if it is not too high) can be beneficial. Why? _________________________________________________________
23. What can modern medicine do to stimulate the immune response? ___________________________________________
24. Physicians sometimes inject cytokines as a treatment for cancer. Why? ______________________________________
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25. The inability to sufficiently stimulate the immune response against cancer has led to the use of chemotherapy.
What is the principle behind chemotherapy? ________________________________________________________________
Test Results: ______ number correct ÷ 25 = ______ × 100 = ______ %
EXPLORING
THE
INTERNET
ARIS, the Essentials of Biology website: http://www.mhhe.com/maderessentials
ARIS, the website for Essentials of Biology, offers access to a wide variety of tools to help students learn biological
concepts and to reinforce their knowledge. Online study aids such as practice quizzes, interactive activities, animations, labeling exercises, flashcards, and much more are organized according to the major sections of each chapter.
There is even an online tutorial service!
ANSWER KEY
CHAPTER KEY TERMS
a. antigen-presenting cell b. cytokine c. immunity
d. vaccine e. active immunity f. allergy g. complement
system h. immune system i. agglutination j. antigen
k. passive immunity l. antibody m. histamine
n. autoimmune disease
c. Immune cells attack tissues of self. 18. a. Helper T
cells decline because HIV reproduces in and kills off
helper T cells. b. The immune system is depressed.
19. sexual relations, both homosexual and heterosexual,
and intravenous drug use
DEFINITIONS WORDSEARCH
STUDY EXERCISES
1. a. S b. RBM c. T d. S e. T f. RBM 2. a. macrophages
and neutrophils b. lymphocytes c. Plasma cells produce
antibodies; memory cells can do so in the future. d. natural killer cells and cytotoxic T cells e. helper T cells
3. a. 2 b. 1 c. 3 d. 1 e. 2 f. 1 g. 4 h. 1 i. 5 4. a. free
nerve ending b. mast cell c. histamine d. capillary
e. neutrophil f. pathogens g. macrophage h. capillary
i. plasma j. mast cell k. pathogens 5. b 6. a 7. b
8. a. antibody b. bone marrow c. plasma 9. a. antigens b. antigen-binding site c. combine with antigens
and mark them for destruction 10. a. A, O b. A, AB
c. B, O d. B, AB e. A, B, AB, O f. AB g. O h. A, B,
AB, O 11. a 12. a. secretes cytokines that stimulate
other immune cells b. destroys cells bearing particular
antigen c. P forms pores and G causes target cell to undergo
apoptosis. 13. a. B b. T c. B d. T e. T f. B g. T h. B
i. T 14. a. cellular b. bone marrow, thymus c. MHC
(major histocompatibility complex) d. antigen-bearing
e. cytokines 15. a. plasma antibody concentration
b. primary response c. secondary response d. first exposure
to vaccine e. second exposure to vaccine f. memory B
16. antibodies 17. a. Antigen attaches to antibodies on
mast cells, and histamine release causes allergic response.
b. Antibodies and cytotoxic T cells attack foreign antigens.
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a. neutrophil b. complement c. autoimmune
d. spleen e. cytokine f. macrophage g. thymus
h. antibody i. histamine j. appendix
CHAPTER TEST
1. d 2. a 3. b 4. a 5. c 6. b 7. d 8. d 9. d
10. c 11. a 12. a 13. d 14. b 15. b 16. c
17. b 18. c 19. c 20. c 21. d 22. It stimulates immune response. 23. vaccinations 24. Cytokines coordinate the immune response. 25. to kill off dividing
cells, including cancer cells