Chapter 15 Innate Immunity
15.1 Multiple Choice Questions
1) The first and second lines of defense against microbial invasion are part of
A) innate immunity.
B) adaptive immunity.
C) species resistance.
D) microbial antagonism.
E) both species resistance and adaptive immunity.
2) Which of the following are phagocytic cells found in the epidermis?
A) neutrophils
B) natural killer lymphocytes
C) microglia
D) dendritic cells
E) wandering macrophages
3) Response to specific pathogens that can improve with subsequent exposure is
A) the first line of defense.
B) the second line of defense.
C) the third line of defense.
D) microbial antagonism.
E) innate immunity.
4) Which of the following cells increase in number during an infection with parasitic worms?
A) basophils
B) macrophages
C) neutrophils
D) eosinophils
E) lymphocytes
5) Which of the following areas of the body have mucous membranes?
A) mouth
B) nasal cavity
C) urinary system
D) mouth and nasal cavity
E) mouth, nasal cavity, and urinary system
6) Protection from infection known as species resistance is a result of
A) the lack of suitable environment in the body.
B) the absence of receptors required for microbial attachment.
C) the presence of phagocytes in the tissues.
D) the salty, acidic condition of normal skin.
E) both the absence of necessary receptors and lack of suitable environment in the body.
7) Which of the following statements regarding the surface of the skin is FALSE?
A) It has sebum as a coating.
B) It has normal microbiota.
C) It has goblet cells.
D) It is salty.
E) It is acidic.
8) Which of the following contributes to protecting the eyes from microbial invasion?
A) Tears contain lysozyme and salt.
B) A mucus layer traps and removes microbes.
C) Tears mechanically flush particles from the eyes.
D) Tears contain lysozyme and salt and mechanically flush particles from the eyes.
E) Tears and mucus combine to trap microbes and remove them.
9) Which of the following is the best definition of “microbial antagonism”?
A) the presence of pathogens on the surface of the skin, which will invade the body through
abrasions
B) the presence of normal microbiota that protect the body by competing with pathogens in a
variety of ways to prevent pathogens from invading the body
C) the presence of normal microbiota that can become pathogens under certain conditions
D) the ability of microbiota to mutate into pathogens
E) the presence of resident bacteria on the surface of the body and in cavities that connect to the
surface
10) Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense
against microbial invaders?
A) The mucus secreted by the mucous membrane physically traps microbes.
B) The mucus contains a variety of antimicrobial chemicals and molecules.
C) Both the mucus and the outer layer of cells are shed frequently.
D) The mucus is a physical trap that contains a variety of antimicrobial chemicals.
E) The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is
shed constantly, along with the outermost layer of cells.
11) Which of the following are chemotactic factors for phagocytes?
A) peptide fragments from complement
B) chemokines
C) interferons
D) interferons and chemokines
E) chemokines and peptide fragments from complement
12) Which of the following statements about eosinophil function is CORRECT?
A) They produce defensins.
B) They secrete toxins onto virally infected cells.
C) They are involved in the removal of neoplastic cells.
D) They attach to the surface of parasitic helminths and produce toxins that kill the parasite.
E) They identify and spare normal cells.
13) Antimicrobial peptides called ________ are secreted in sweat and damage bacteria and
fungi.
A) antibodies
B) dermicidins
C) TLRs
D) complement factors
E) cytokines
14) The complement cascade and its by-products contribute to
A) attracting phagocytes to sites of infection.
B) triggering inflammation.
C) triggering release of interferons.
D) triggering inflammation and release of interferons.
E) both triggering inflammation and attracting phagocytes to sites of infection.
15) Cells of the second line of defense called ________ recognize and kill virus-infected cells.
A) basophils
B) eosinophils
C) macrophages
D) NK cells
E) dendritic cells
16) The process of phagocytosis involve all of the following EXCEPT
A) chemotaxis.
B) secretion of cytotoxins.
C) adhesion.
D) elimination.
E) vesicle fusion.
17) Which of the following cells can use nonphagocytic means to kill bacteria?
A) eosinophils
B) macrophages
C) neutrophils
D) natural killer cells
E) both eosinophils and neutrophils
18) Which of the following are phagocytic cells descended from monocytes?
A) alveolar macrophages
B) dendritic cells
C) microglial cells
D) alveolar macrophages and dendritic cells
E) alveolar macrophages and microglial cells
19) Which of the following cells is a component of the body’s first line defense?
A) monocyte
B) goblet cell
C) NK cell
D) neutrophil
E) microglial cells
20) Which of the following leukocytes have granules in their cytoplasm that stain blue with
methylene blue?
A) eosinophils
B) monocytes
C) lymphocytes
D) neutrophils
E) basophils
21) Which cell becomes a macrophage when leaving the bloodstream?
A) monocyte
B) lymphocyte
C) basophil
D) eosinophil
E) neutrophil
22) The components of the second line of defense against microbes may be characterized as
A) responders to invasion.
B) passive barriers.
C) mechanisms to strengthen the first line of defense.
D) detecting the unique features of specific pathogens.
E) both passive barriers and detecting specific pathogen features.
23) Which of the following proteins are part of the first line of defense against microbial
invasion?
A) dermacidins
B) TLRs
C) NOD proteins
D) C3 and C5
E) interferons
24) Which of the following are among the activities of neutrophils?
A) formation of neutrophil extracellular traps
B) phagocytosis
C) enzyme production that leads to the formation of nitric oxide
D) formation of neutrophil extracellular traps and phagocytosis
E) formation of neutrophil extracellular traps, phagocytosis, and production of nitric oxide
25) Which of the following is an iron-binding protein produced by pathogens to access the
body’s store of iron?
A) gastroferritin
B) lactoferrin
C) ferritin
D) transferrin
E) siderophores
26) Which of the following statements regarding phagocyte recognition of pathogens is TRUE?
A) TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.
B) TLRs on the surface of microbes trigger the accumulation of opsonins.
C) Lectins on the surface of microbes are bound by chemokine receptors.
D) NOD proteins on the surface of microbes are detected by TLRs.
E) MACs on the surface of microbes are detected by NOD proteins.
27) Alpha and beta interferons
A) help protect virus-infected cells from the effects of the pathogen.
B) protect the cells that secrete them from being invaded by a virus.
C) are produced by infected fibroblasts and macrophages.
D) produce active antiviral proteins (AVPs) that coat the surface of healthy cells and prevent
the attachment of pathogenic viruses.
E) produce no adverse effects in the body.
28) Which of the following substances stimulates the phagocytic activity of phagocytes?
A) gamma interferons
B) alpha interferons
C) beta interferons
D) antiviral proteins
E) leukotrienes
29) The alternative pathway of complement cascade activation begins with ________ binding
to the surface of a microbe.
A) C1
B) C3a
C) complement factor B
D) C5a
E) C5b
30) Fever is beneficial during viral infection because the higher temperature
A) inactivates interferons.
B) increases vasodilation, contributing to inflammation.
C) increases sweating and consequently the barrier effect.
D) prevents viral infection of fibroblasts.
E) increases the effectiveness of interferons and phagocytes.
31) Which of the following substances contributes to the edema associated with inflammation?
A) leukotrienes
B) histamine
C) interferon
D) defensin
E) both leukotrienes and histamine
32) Which of the following is NOT an example of a walled-off site of infection that contains a
fluid made of dead and dying tissue cells, leukocytes, and pathogens?
A) a boil
B) an abscess
C) a pimple
D) a pustule
E) a tumor
33) How does aspirin act to decrease the symptoms of inflammation?
A) It acts as an antiprostaglandin.
B) It is an antitoxoid for most microbial toxins.
C) It prevents complement activation.
D) It interferes with the action of interferons.
E) It blocks the release of histamine.
34) Which of the following are macrophage functions?
A) phagocytosis of pathogens and debris
B) release of alpha interferon
C) production of NETs
D) phagocytosis of pathogens and production of NETs
E) phagocytosis of pathogens and secretion of alpha interferons and leukotrienes
35) Which of the following characteristics is shared by the skin and mucous membranes?
A) They are both constantly shedding and replacing cells.
B) They both have cilia.
C) The outer layers are composed of dead cells.
D) Sebum may be present.
E) Lysozymes are always present.
36) The phenomenon known as chemotaxis is defined as
A) the squeezing of cells through the lining of capillaries.
B) the release of prostaglandins and leukotrienes in response to microbes.
C) the movement of a cell toward or away from a chemical stimulus.
D) the coating of a pathogen by complement.
E) an increase in allergies and helminth infection.
37) Opsonization is
A) the coating of a pathogen by complement to facilitate phagocytosis.
B) the sticking of monocytes to the wall of the blood vessels at the site of infection.
C) damage resulting in cell lysis.
D) nonspecific leukocyte secretion of toxins onto the surface of virally infected cells.
E) phagocyte receptors detecting PAMPs.
38) Proteins on the surface of phagocytes called ________ aid in the detection of pathogen
molecules.
A) lectins
B) TLRs
C) NOD proteins
D) lectins and C3 protein
E) both TLRs and NOD proteins
39) A type of lymphocyte called a(n) ________ detects cells with abnormal surface proteins
and kills them.
A) eosinophil
B) NK cell
C) neutrophil
D) basophil
E) mast cell
40) Which of the following statements is TRUE of eosinophils?
A) They are in intact skin, sebum, tears, etc.
B) They produce the coating of a pathogen by complement.
C) They secrete toxins onto the surface of helminth parasites.
D) They decline during allergic reaction.
E) They release prostaglandins and leukotrienes in response to microbes.
41) Microbial molecules detected by phagocytes are called
A) TLRs.
B) NODs.
C) PAMPs.
D) leukotrienes.
E) prostaglandins.
42) TLRs are
A) phagocyte receptors that detect PAMPs.
B) the coatings of pathogens by complement.
C) molecules that damage cells, resulting in cell lysis.
D) present in intact skin, sebum, tears, etc.
E) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
43) The leukocytes called natural killer lymphocytes
A) release prostaglandins and leukotrienes in response to microbes.
B) increase in allergies and helminth infection.
C) respond to the coating of a pathogen by complement.
D) are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
E) are specialists in killing bacteria.
44) First line of defense may be described as
A) the release of prostaglandins and leukotrienes in response to microbes.
B) intact skin, mucous membranes, sebum, tears, and so forth.
C) damage resulting in cell lysis.
D) the coating of a pathogen by complement.
E) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
45) Sebum contains ________ which contributes to creating an inhospitable environment on
the surface of the body.
A) lysozyme
B) collagens
C) acids
D) salts
E) bile
15.2 True/False Questions
1) Interferons alpha and beta are effective against viruses.
2) The resident microbiota have no role in defense against pathogen invasion.
3) Sweat can cause damage to bacteria because it contains salt and lysozyme.
4) The phenomenon known as species resistance is a highly specific defense against infectious
agents.
5) Some toll-like receptors (TLRs) are found on the surface of host cells and recognize specific
microbial molecules.
6) Innate immunity is not effective against fungus infections.
7) Histamine and prostaglandins are involved in inflammatory reactions.
8) The growth of some microbes is inhibited by elevated body temperature.
9) Neutrophils can kill bacteria by nonphagocytic mechanisms.
10) Inflammation is an important part of the body’s first line of defense, and it involves
migration of phagocytes to the area.
15.3 Short Answer Questions
1) The first and second lines of defense respond to invading microbes by (specific/nonspecific)
mechanisms.
2) The absence of necessary receptors is the basis of the defense against microbial invasion
known as (natural/innate/species) resistance.
3) Sweat glands produce (lysozyme/dermacidin/acid), which destroys the cell wall of bacteria
by cleaving the bonds between the sugar subunits.
4) The (epithelial/goblet/mucous) cells in the tracheal mucous membrane produce mucus.
5) The oily substance that lowers the pH of the skin’s surface to about pH 5 and is inhibitory to
many bacteria is (sebum/sweat/serum).
6) The normal microbiota compete with pathogens in a variety of ways to protect the body,
creating a situation known as microbial (antagonism/competition/resistance).
7) In a process called (cytokinesis/hematopoiesis/hematocrit), blood stem cells located in the
bone marrow produce the three types of formed elements found in the blood.
8) Nonphagocytic (eosinophils/monocytes/NK cells) are a type of lymphocyte which produce
toxins to kill abnormal cells.
9) Neutrophils use their own (DNA/RNA/TLR) in the formation of NETs to trap bacteria.
10) The proportion of (plasma/leukocytes/RBCs), as determined by a differential white blood
cell count, can serve as a sign of disease.
11) Eosinophils respond to (complement/lipopolysaccharide/histamines) and kill bacteria in a
nonphagocytic process.
12) Macrophages release (bradykinin/histamine/prostaglandin) in response to microbes and
thereby contribute to acute inflammation.
13) Phagocytes kill a pathogen once it has been ingested, whereas eosinophils and
(MAC/NK/NOD) lymphocytes can accomplish extracellular killing by secreting toxins. (Be
sure to use capital letters in your answer.)
14) Intact skin layers are part of the body’s (first/second/third) line of defense against
pathogens.
15) Some pathogens produce toxins which function as (histamines/prostaglandins/pyrogens) to
cause fever.
15.4 Essay Questions
1) Describe the events of the acute inflammatory response and their effect on a site of infection.
Include the cells and chemicals involved.
2) What are macrophages, and what are their functions?
3) Describe at least three physical mechanisms that are part of the first line of defense.
4)
Examine the WBC count and differential data in Table 15.1. What type of disease is indicated
by this set of data?
5) What is phagocytosis? What does it involve?