Microbiology: An Introduction, 13e (Tortora et al.)
Chapter 16 Innate Immunity: Nonspecific Defenses of the Host
16.1 Multiple-Choice Questions
1) Innate immunity
A) is slower than adaptive immunity in responding to pathogens.
B) is nonspecific and present at birth.
C) involves a memory component.
D) involves T cells and B cells.
E) provides increased susceptibility to disease.
2) All of the following protect the skin and mucous membranes from infection EXCEPT
A) multiple layers of cells.
B) tears.
C) saliva.
D) HCl.
E) the “ciliary escalator.”
3) The function of the “ciliary escalator” is to
A) propel inhaled dust and microorganisms away from the mouth, toward the lower respiratory
tract.
B) remove microorganisms from the gastrointestinal tract.
C) remove microorganisms from the lower respiratory tract.
D) trap microorganisms in mucus in the upper respiratory tract.
E) trap inhaled dust and microorganisms in mucus and propel it away from the lower respiratory
tract.
4) Which of the following exhibits the highest phagocytic activity?
A) eosinophils
B) erythrocytes
C) macrophages
D) basophils
E) neutrophils
5) TLRs attach to all of the following EXCEPT
A) AMPs.
B) flagellin.
C) LPS.
D) PAMPs.
E) peptidoglycan.
6) A differential cell count is used to determine each of the following EXCEPT
A) the total number of white blood cells.
B) the numbers of each type of white blood cell.
C) the number of red blood cells.
D) leukocytosis.
E) leukopenia.
7) The complement protein cascade is the same for the classical pathway, alternative pathway,
and lectin pathway after the point in the cascade where the activation of ________ takes place.
A) C1
B) C2
C) C3
D) C5
E) C6
8) All of the following increase blood vessel permeability EXCEPT
A) kinins.
B) prostaglandins.
C) lysozymes.
D) histamine.
E) leukotrienes.
9) A child falls and suffers a deep cut on her leg. The cut went through her skin and she is
bleeding. Which of the following defense mechanisms will participate in eliminating
contaminating microbes?
A) mucociliary escalator
B) normal skin flora
C) phagocytosis in the inflammatory response
D) acidic skin secretions
E) lysozyme
10) Margination refers to
A) the adherence of phagocytes to microorganisms.
B) the chemotactic response of phagocytes.
C) adherence of phagocytes to the lining of blood vessels.
D) dilation of blood vessels.
E) the movement of phagocytes through walls of blood vessels.
11) Which of the following statements is TRUE?
A) All three types of interferons have the same effect on the body.
B) Alpha interferon promotes phagocytosis.
C) Gamma interferon causes bactericidal activity by macrophages.
D) Alpha interferon acts against specific viruses.
E) Beta interferon attacks invading viruses.
12) Which of the following is found normally in serum?
A) complement
B) interferon
C) histamine
D) leukocytosis-promoting factor
E) TLRs
13) Each of the following is an effect of complement activation EXCEPT
A) interference with viral replication.
B) bacterial cell lysis.
C) opsonization.
D) increased phagocytic activity.
E) increased blood vessel permeability.
14) Which of the following is an effect of opsonization?
A) increased adherence of phagocytes to microorganisms
B) increased margination of phagocytes
C) increased diapedesis of phagocytes
D) inflammation
E) cytolysis
15) Normal microbiota provide protection from infection in each of the following ways EXCEPT
A) they produce antibacterial chemicals.
B) they compete with pathogens for nutrients.
C) they make the chemical environment unsuitable for nonresident bacteria.
D) they produce lysozyme.
E) they change the pH of the environment.
16) Each of the following provides protection from phagocytic digestion EXCEPT
A) M protein.
B) capsules.
C) formation of phagolysosomes.
D) leukocidins.
E) biofilms.
17) The antimicrobial effects of AMPs include all of the following EXCEPT
A) inhibition of cell wall synthesis.
B) lysis of bacterial cells.
C) destruction of nucleic acids.
D) pore formation in bacterial membranes.
E) inhibition of phagocytosis.
18) The swelling associated with inflammation decreases when the fluid
A) returns to the blood.
B) goes into lymph capillaries.
C) is excreted in urine.
D) is lost as perspiration.
E) is transported into macrophages.
19) Which of the following statements about fixed macrophages is FALSE?
A) They are found in certain tissues and organs.
B) They develop from neutrophils.
C) They are cells of the mononuclear phagocytic system.
D) They are mature monocytes.
E) They gather at sites of infection.
20) Phagocytes utilize all of the following to optimize interaction with (getting to and getting
hold of) microorganisms EXCEPT
A) trapping a bacterium against a rough surface.
B) opsonization.
C) chemotaxis.
D) lysozyme.
E) complement.
21) All of the following are effects of histamine EXCEPT
A) vasodilation.
B) fever.
C) swelling.
D) redness.
E) pain.
22) All of the following are effects of kinins EXCEPT
A) vasodilation.
B) increased blood vessel permeability.
C) chemotaxis of phagocytic granulocytes.
D) drawing in neutrophils to infected or injure area.
E) production of antibodies.
23) A chill is a sign that
A) body temperature is falling.
B) body temperature is rising.
C) body temperature is not changing.
D) the metabolic rate is decreasing.
E) blood vessels are dilating.
24) Which of the following statements is TRUE?
A) There are at least thirty complement proteins.
B) All of the complement proteins are constantly active in serum.
C) Factors B, D, and P cause cytolysis.
D) Complement activity is antigen-specific.
E) Complement increases after immunization.
25) Which of the following is mismatched?
A) diapedesis – movement of leukocytes between capillary walls cells out of blood and into
tissue
B) chemotaxis – chemical degradation inside a phagolysosome
C) abscess – a cavity created by tissue damage and filled with pus
D) pus – tissue debris and dead phagocytes in a white or yellow fluid
E) scab – dried blood clot over injured tissue
26) All of the following are part of the mechanism of action of alpha and beta interferons
EXCEPT
A) they bind to the surface of uninfected cells.
B) they are effective for long periods.
C) they initiate manufacture of antiviral proteins.
D) they disrupt stages of viral multiplication.
E) they initiate transcription.
27) The alternative pathway for complement activation is initiated by
A) lipid-carbohydrate complexes and C3.
B) C5-C9.
C) antigen-antibody reactions.
D) factors released from phagocytes.
E) factors released from damaged tissues.
28) The classical pathway for complement activation is initiated by
A) lipid-carbohydrate complexes and C3.
B) C5-C9.
C) antigen-antibody reactions.
D) factors released from phagocytes.
E) factors released from damaged tissues.
29) Activation of C3a results in
A) acute inflammation.
B) increased blood vessel permeability.
C) opsonization.
D) attraction of phagocytes.
E) cell lysis.
30) Neutrophils with defective lysosomes are unable to
A) undergo chemotaxis.
B) migrate.
C) produce toxic oxygen products.
D) attach to microorganisms and other foreign material.
E) engulf microorganisms and other foreign material.
31) Innate immunity includes all of the following EXCEPT
A) phagocytosis.
B) inflammation.
C) production of antibody.
D) production of interferon.
E) activation of complement.
32) After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT
A) complement.
B) O2-.
C) H2O2.
D) OH.
E) HOCl.
33) Activation of C5-C9 results in
A) activation of C3.
B) fixation of complement.
C) lysis of microbial cells.
D) phagocytosis.
E) inflammation.
34) All of the following are true regarding NK cells EXCEPT
A) they are a type of lymphocyte.
B) they are found in tissues of the lymphatic system.
C) they have the ability to kill infected body cells and some tumor cells.
D) they destroy infected body cells by phagocytosis.
E) they release toxic substances that cause cell lysis or apoptosis.
35) Which of the following is involved in resistance to parasitic helminths?
A) basophils
B) eosinophils
C) lymphocytes
D) monocytes
E) neutrophils
36) Macrophages arise from which of the following?
A) basophils
B) eosinophils
C) lymphocytes
D) monocytes
E) neutrophils
37) All of the following pertain to fever EXCEPT that it
A) accelerates microbial growth by increasing iron absorption from the digestive tract.
B) stimulates T lymphocyte activity.
C) is caused by interleukin-1 and TNF-alpha coming into contact with the hypothalamus.
D) intensifies the effect of antiviral interferons.
E) can be initiated by specific types of pathogens.
38) All of the following are iron-binding proteins found in humans EXCEPT
A) lactoferrin.
B) transferrin.
C) hemoglobin.
D) siderophorin.
E) ferritin.
39) All of the following occur during inflammation. What is the first step?
A) diapedesis
B) margination
C) phagocyte migration
D) repair
E) vasodilation
40) The lectin pathway for complement action is initiated by
A) mannose on host membranes.
B) mannose on the surface of microbes.
C) lectins of the microbe.
D) gram-negative cell walls.
E) gram-positive cell walls.
41) All of the following are components of the inflammatory process EXCEPT
A) dilation of blood vessels.
B) release of histamines and prostaglandins.
C) chemotaxis.
D) diapedesis.
E) antibody synthesis.
42) Several inherited deficiencies in the complement system occur in humans. Which of the
following would be the MOST severe?
A) deficiency of C3
B) deficiency of C5
C) deficiency of C6
D) deficiency of C7
E) deficiency of C8
43) Which of the following statements about the classical pathway of complement activation is
FALSE?
A) C1 is the first protein activated in the classical pathway.
B) The C1 protein complex is initiated by antigen-antibody complexes.
C) C3 is not involved in the classical pathway.
D) Cleaved fragments of some of the proteins act to increase inflammation.
E) C3b causes opsonization.
44) Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both
cause damage to the bacterial
A) cell membrane.
B) capsule.
C) cell wall.
D) DNA.
E) ribosomes.
45) Which non-specific defense mechanism is mismatched with its associated body structure or
body fluid?
A) lysozyme – tears and saliva
B) mucociliary escalator – intestines
C) very acidic pH – stomach
D) keratin and tightly packed cells – skin
E) cerumen and sebum – ear
46) Leukotrienes are inflammatory vasoactive mediators produced by
A) neutrophils.
B) eosinophils.
C) skin cells.
D) macrophages.
E) mast cells and basophils.
47) Which one of the following compounds intensifies the effects of histamine and helps
phagocytes migrate through capillary walls?
A) kinins
B) prostaglandins
C) antibodies
D) leukotrienes
E) IFN-γ
48) Chronic inflammation can result in a(n) ________, which can cause impairment of normal
tissue function.
A) abscess
B) fever
C) scar tissue/fibrosis
D) parenchyma
E) blood clot
49) Death results if body temperature rises above
A) 35° to 37° C.
B) 30° to 32° C.
C) 39° to 41° C.
D) 44° to 46° C.
50) Which one of the following is a regulatory protein that prevents the assembly of C9
molecules in the complement cascade, effectively shutting down MAC production?
A) C3b
B) properdin
C) C3a
D) C3a receptor
E) CD59
16.2 True/False Questions
1) The dermis is composed of connective tissue and serves the primary purpose of providing
direct protection from the external environment.
2) Microorganisms that are members of the normal microbiota are also known to cause disease.
3) Maturation of stem cells into mature blood cells occurs in the red bone marrow.
4) The inflammatory response can only be triggered by an infection.
5) Histamine and kinins cause increased blood flow and capillary permeability.
6) Aspirin alleviates pain, inflammation, and fever by inhibiting prostaglandins.
7) Complement proteins in their intact and nonactivated form act as opsonins by binding to
microorganisms and promoting phagocytosis.
8) Digestion of microorganisms occurs in phagosomes.
9) An example of a TLR would be peptidoglycan found in the cell wall of gram-positive
bacteria.
10) Ingestion of certain lactic acid bacteria (LABs) has been shown to be beneficial for function
and health of the intestinal tract.
16.3 Essay Questions
1) If you were interested in seeking new sources of antimicrobial drugs from natural sources, you
might look to antimicrobial peptides. Identify possible sources for these drugs, and then describe
how you might go about testing for their desired effects.
2) The complement system is extremely important in the innate defense response. It can be said
that this system is a cascade system. Explain this statement.
3) Describe the nonspecific antimicrobial effects of mucus, lysozyme, and acidic pH. For each of
these substances, list where they are found in the body and how they function in fighting
pathogens.
4) Describe and differentiate between the three pathways of activating complement.
5) Iron is an important item for the growth of microorganisms in a pathogenic state in the human
body. Describe two ways in which bacteria might attempt to obtain iron from human cells or
tissues for their own use. Then, describe a way in which this bacterial iron-scavenging might be
disrupted without harming the human cells/tissues in the process.