Microbiology Chapter 16 Innate Immunity
Cells produce alpha interferon and beta interferon in response to __________.
a. helminthic infections
b. protozoan infections
c. viral infections
d. bacterial infections
c. viral infections
Which of these cells do NOT have phagocytic activity?
a. eosinophils
b. neutrophils
c. lymphocytes
d. macrophages
c. lymphocytes
Which complement protein directly forms the membrane attack complex (MAC)?
a. C3
b. C5
c. C1
d. C9
d. C9
Which of these complement proteins binds to the surface of microbes and enhances phagocytosis in a process termed opsonization?
a. C1
b. C5
c. C3b
d. C9
c. C3b
Which of the following does NOT accurately describe innate immunity?
a. It includes inflammation, fever, and phagocytosis.
b. It includes the first and second lines of defense.
c. It includes defenses present at birth.
d. It produces strong, long-lasting memory responses.
d. It produces strong, long-lasting memory responses.
Which of the following is NOT a chemical factor that helps the skin to be relatively resistant to infection?
a. sebum
b. complement proteins
c. acidic pH
d. lysozyme
b. complement proteins
Which term best describes the symbiotic relationship between humans and most of the normal microbiota that live on our human skin?
a. pathological
b. parasitism
c. commensalism
d. mutualism
c. commensalism
__________ are involved in detecting foreign invaders. They do so by binding to pathogen- associated molecular patterns (PAMPs) on the surface of the pathogen.
a. Mucous membranes
b. Inflammatory molecules
c. Toll-like receptors
d. Granzymes
c. Toll-like receptors
The presence of a capsule and the M protein of Streptococcus pyogenes are both involved in __________.
a. helping a virus change its surface antigens
b. helping bacteria kill phagocytes
c. helping bacteria survive inside a phagocyte
d. helping bacteria resist phagocytosis
d. helping bacteria resist phagocytosis
__________ are inflammatory molecules that are usually found in blood in an inactive form. Once activated, they help to attract neutrophils to the injured area.
a. Leukotrienes
b. Kinins
c. Prostaglandins
d. Histamines
b. Kinins
When attracted to an infected area, macrophages can leave the bloodstream by squeezing through the endothelial cells lining a blood vessel. What is this process called?
a. margination
b. adherence
c. opsonization
d. diapedesis
d. diapedesis
Which type of leukocyte is the most abundant in blood?
a. lymphocytes
b. eosinophils
c. monocytes
d. neutrophils
d. neutrophils
What is the effect of alpha interferon on an uninfected cell?
a. It causes the cell to activate complement.
b. It causes the cell to produce antiviral proteins.
c. It causes the cell to release histamines.
d. It causes the cell to undergo chemotaxis.
b. It causes the cell to produce antiviral proteins.
The __________ controls normal body temperature; it is stimulated to reset the body to a higher temperature in response to some infections.
a. thymus
b. complement cascade
c. lacrimal apparatus
d. hypothalamus
d. hypothalamus
What is the correct name for the fluid that is collected from the body by lymphatic capillaries?
a. complement
b. interstitial fluid
c. blood
d. plasma
b. interstitial fluid
Which of the following is NOT an advantage of antimicrobial peptides?
a. They have a narrow spectrum of activity, so they are very specific.
b. Microorganisms do not seem to develop resistance to them.
c. They exhibit synergy when used with other antimicrobial compounds.
d. They are very stable.
a. They have a narrow spectrum of activity, so they are very specific.
Which of the following describes the correct chronological order of events in phagocytosis?
a. ingestion, adherence, digestion, chemotaxis
b. chemotaxis, adherence, ingestion, digestion
c. chemotaxis, ingestion, adherence, digestion
d. ingestion, digestion, adherence, chemotaxis
b. chemotaxis, adherence, ingestion, digestion
Which of the following statements concerning lysozyme is FALSE?
a. It is found in many different body fluids.
b. It is an organelle in white blood cells.
c. It is an enzyme.
d. It breaks down peptidoglycan.
b. It is an organelle in white blood cells.
Your lab partner slipped on his way to class and scraped his arm on the concrete. You make a smear of the fluid from his scrape and observe large nucleated cells. These cells are most likely __________.
a. erythrocytes
b. bacteria
c. lymphocytes
d. neutrophils
d. neutrophils
Edema is defined as a collection of fluid in an area of the body. What is the physiological change that causes edema?
a. activation of complement
b. increased permeability of blood vessels
c. fever
d. constriction of blood vessels
b. increased permeability of blood vessels
Which of the following are considered part of the host adaptive defense?
a. antibodies
b. inflammation
c. cytotoxic T cells
d. skin
e. complement system
a. antibodies
and
c. cytotoxic T cells
Antigen presentation is directly involved in which of the following host defenses?
a. inflammation
b. cell-mediated immunity
c. complement system
d. phagocytosis
e. humoral immunity
e. humoral immunity
and
b. cell-mediated immunity
Which of the following defense system would likely be involved in destroying cancer cells?
a. inflammation
b. phagocytosis
c. humoral immunity
d. cell-mediated immunity
d. cell-mediated immunity
Antibodies are produced by _________________.
a. cytotoxic T cells
b. phagocytes
c. B cells
d. helper T cells
c. B cells
A leukocyte with visible granules in the cytoplasm when viewed through a light microscope; includes neutrophils, basophils, and eosinophils.
granulocyte
The number of each kind of leukocyte in a sample of 100 leukocytes.
differential white blood cell count
A food vacuole of a phagocyte; also called a phagocytic vesicle.
phagosome
Small peptide antibiotics made by human cells.
defensins
The microorganisms that colonize a host without causing disease; also called normal flora.
normal microbiota
The process by which phagocytes move out of blood vessels.
diapedesis
An enzyme capable of hydrolyzing bacterial cell walls.
lysozyme
A small protein released from human cells that regulates the immune response; directly or indirectly may induce fever, pain, or T cell proliferation.
cytokine
The process by which phagocytes stick to the lining of blood vessels.
margination
A localized accumulation of pus.
abscess
A group of serum proteins involved in phagocytosis and lysis of bacteria.
complement
A macrophage that is located in a certain organ or tissue (e.g., liver, lungs, spleen, or lymph nodes); also called a histiocyte.
fixed macrophage
A granulocyte (leukocyte) that readily takes up basic dye and is not phagocytic; has receptors for IgE Fc regions.
basophil
Chemicals that promote growth of beneficial bacteria in the body.
prebiotics
An antibiotic that is bactericidal and has a broad spectrum of activity; see bacteriocin.
antimicrobial peptide (AMP)
Microbes inoculated into a host to occupy a niche and prevent growth of pathogens.
probiotics
An abnormally high body temperature.
fever
Ciliated mucosal cells of the lower respiratory tract that move inhaled particulates away from the lungs.
ciliary escalator
A lymphoid cell that destroys tumor cells and virus-infected cells.
natural killer (NK) cell
See mononuclear phagocytic system.
reticuloendothelial system
The formation of blood cells.
hematopoiesis
An appendage on a bacterial cell used for attachment.
fimbria or fimbriae
A leukocyte that is the precursor of a macrophage.
monocyte
An extension of a eukaryotic cell that aids in locomotion and feeding.
pseuopod
A leukocyte without visible granules in the cytoplasm when viewed through a light microscope; includes monocytes and lymphocytes.
agranulocyte
Protein that makes a pore in a target cell membrane, released by cytotoxic T lymphocytes.
perforin
Molecules present on pathogens and not self.
PAMP (pathogen-associated molecular patterns)
The living together of two different organisms or populations.
symbiosis
The ability to ward off diseases through innate and adaptive immunity.
resistance
A type of lymphocyte; differentiates into anti-body-secreting plasma cells and memory cells.
B cell
A substance released from tissue cells that cause vasodilation.
kinin
A leukocyte involved in specific immune responses.
lymphocyte
The ability, obtained during the life of the individual, to produce specific antibodies and T cells.
adaptive immunity
A protein made in response to interferon that blocks viral multiplication.
Antiviral protein (AVP)
Attachment of a microbe or phagocyte to another's plasma membrane or other surface.
adherence
The inner portion of the skin.
dermis
Carbohydrate-binding proteins on a cell, not an antibody.
lectin
The enhancement of phagocytosis by coating microorganisms with certain serum proteins (opsonins); also called immune adherence.
opsonization
Molecules on T cells that recognize antigens.
TCRs (T cell receptors)
A white blood cell.
Leukocyte
Complement proteins C5-C9, which together make lesions in cell membranes that lead to cell death.
membrane attack complex (MAC)
A host response to tissue damage characterized by redness, pain, heat, and swelling; and sometimes loss of function.
inflammation
A phagocytic cell; a mature monocyte. See fixed macrophage, free wandering macrophage.
macrophage
A rapid screening test to detect the presence of antibodies against Treponema pallidum. (VDRL stands for Venereal Disease Research Laboratory.)
VDRL test
The ingestion of particles by eukaryotic cells.
phagocytosis
An accumulation of dead phagocytes, dead bacterial cells and fluid.
pus
A macrophage that leaves the blood and migrates to infected tissue.
free (wandering) macrophage
A substance released by tissue cells that causes vasodilation, capillary permeability, and smooth muscle contraction.
histamine
The phase of a fever characterized by vasodilation and sweating.
crisis
A digestive vacuole
phagolysosome
Proteases that include apoptosis.
granzymes
The outer portion of the skin.
epidermis
Host defenses that afford protection against any kind of pathogen. See also adaptive immunity.
innate immunity
A highly phagocytic granulocyte; also called polymorphonuclear leukocyte (PMN) or polymorph.
neutrophil
A hormone like substance that is released by damaged cells, intensifies inflammation.
prostaglandin
A cell capable of engulfing and digesting particles that are harmful to the body.
phagocyte
An abnormal accumulation of interstitial fluid in tissues, causing swelling.
edema
Serum proteins whose concentration changes by at least 25% during inflammation.
acute-phase proteins
A mammalian organ responsible for maturation of the immune system.
thymus
An enzyme that activates another protein by adding a P from ATP.
protein kinase
The type of RNA molecule that brings amino acids to the ribosomal site where they are incorporated into proteins.
transfer RNA (tRNA)
Bacterial iron-binding proteins.
siderophore
A system of fixed macrophages located in the spleen, liver, lymph nodes, and red bone marrow.
mononuclear phagocytic system
The destruction of cells, resulting from damage to their cell membrane, that causes cellular contents to leak out.
cytolysis
A granulocyte whose granules take up the stain eosin.
eosinophil
Membranes that line body openings, include the intestinal tract, open the exterior; also called mucosa.
mucous membranes
A specific group of cytokines. Alpha- and beta- IFNs are antiviral proteins produces by certain animal cells in response to a viral infection. Gamma- IFN stimulates macrophage activity.
interferon (IFN)
See neutrophil.
polymorphonuclear leukocyte (PMN)
A substance produced by mast cells and basophils that cause increase permeability of blood vessels and helps phagocytes attach to pathogens.
leukotriene
Dilation or enlargement of blood vessels.
vasodilation
Inflammation is categorized as which line of defense?
second
Which of the following are involved in the adaptive immune response?
antibodies
Which of the following would be considered a defense against a bacterial pathogen?
mucous membranes
skin
cytotoxic cells
all of the above
all of the above
Which of the following would be involved in defending the body against all pathogens?
first and second line defenses
Which of the following are involved in host surveillance of pathogens?
antibodies
phagocytes
cytotoxic T-cells
all of the above
none of the above
all of the above
How do bacteria such as Listeria escape phagocytosis?
They resist lysosomal enzymes.
They prevent the fusion of the phagosome with the lysosome.
They inhibit the oxidative burst pathway.
They literally escape from the phagosome.
They literally escape from the phagosome.
How does Streptococcus pneumoniae avoid destruction by the host immune system?
It resists phagocytosis.
It produces a capsule, which makes it undetectable by the immune system.
It alters its surface antigens frequently.
all of the above
none of the above
It produces a capsule, which makes it undetectable by the immune system.
Why does altering surface antigens help pathogens hide from the immune system?
It allows the cells to destroy the antibodies that detect it.
It allows the pathogens to replicate inside the phagocyte.
It prevents the cells from being phagocytized.
It selects for surface antigens that are not recognized by the immune system.
It selects for surface antigens that are not recognized by the immune system.
Why is peptidoglycan an antigen that immune cells detect?
It enables the phagocytes to easily grab the bacterium.
It is rather large.
It is unique to bacteria, and absent from host cells.
It is unique to bacteria, and absent from host cells.
What is the function of leukocidins?
killing of phagocytes
How might Neisseria inactivate host defenses?
They secrete peptidase to destroy IgA AND they use a control molecule mimic to inactivate the complement system.
How do superantigens help a pathogen survive?
They distract the host from eliciting a specific immune response against the pathogen.
Which pathogen would use immune system suppression to evade destruction by the host?
measles
Which of these molecules or structures is/are NOT associated with innate immunity?
macrophages
lysozyme
phagocytes
mucous membranes
antibodies
antibodies
The epidermis __________.
serves as one of the more common portals of entry for pathogens
is below the dermis
is composed of loosely packed cells
is composed largely of epidermal cells, all of which are alive
contains the protein keratin
contains the protein keratin
The ID50 for many pathogens is significantly smaller when testing with gnotobiotic animals compared to animals with normal microbiota. This is likely because of __________.
commensalism
microbial antagonism
impaired phagocytosis
complement inactivation
parasitism
microbial antagonism
The respiratory system is protected against harmful microbes by all of the following EXCEPT __________.
ciliated cells
the epiglottis
the lacrimal apparatus
mucus-coated hairs
the ciliary escalator
the lacrimal apparatus
Which of the following statements about sebum is NOT true?
It raises the pH of skin.
Accutane limits acne by preventing its formation.
It is secreted by sebaceous glands.
Its metabolism can result in acne.
It has antimicrobial properties.
It raises the pH of skin.
One remarkable finding on a patient's laboratory workup is a marked eosinophilia. This might be suggestive of __________.
a parasitic infection
a viral infection
an allergic (hypersensitivity) reaction
a bacterial infection
either a parasitic infection or an allergic (hypersensitivity) reaction
either a parasitic infection or an allergic (hypersensitivity) reaction
Which of these structures are NOT part of the mononuclear phagocytic system?
lymphocytes
Kupffer's cells
alveolar macrophages
microglial cells
wandering macrophages
lymphocytes
Which answer is NOT true for adherence of a phagocyte to a microbe?
Antibody molecules attached to the microbe will limit adherence.
The M protein of Streptococcus pyogenes limits adherence.
Adherence is a critical step in phagocytosis.
Complement molecules attached to the microbe can enhance adherence.
A capsule limits adherence.
Antibody molecules attached to the microbe will limit adherence.
Which answer is true for bacterial destruction by phagocytosis?
Phagolysosomes have a neutral pH.
Listeria monocytogenes is killed within the phagolysosome.
Lipids and proteins, but not nucleic acids, can be digested inside lysosomes.
Toxic oxygen products, such as hydrogen peroxide, are removed.
Myeloperoxidase in lysosomes is involved in the formation of HOCl.
Myeloperoxidase in lysosomes is involved in the formation of HOCl.
The stage of phagocytosis in which the phagocyte's plasma membrane attaches to the surface of the microbe is called __________.
cytolysis
ingestion
fusion
chemotaxis
adherence
adherence
Which answer is NOT true of the inflammatory process?
The area becomes red because of a decrease in capillary diameter.
Kinins cause increased capillary permeability.
Leukotrienes cause increased capillary permeability.
Swelling occurs because of vasodilation and increased capillary permeability.
Edema occurs.
The area becomes red because of a decrease in capillary diameter.
Which of the following statements is NOT true of inflammation?
Granulocytes that have died are commonly engulfed by macrophages.
Vasodilation causes redness in affected tissues.
Inflammation can be triggered by microbial infection, burns, exposure to chemicals, or trauma.
Many neutrophils can be found at the site of chronic inflammation.
Histamine released by damaged host cells can result in vasodilation.
Many neutrophils can be found at the site of chronic inflammation.
Activation of the complement cascade __________.
can reduce inflammation
reduces swelling in affected tissues
typically reduces the ability of phagocytes to engulf microbes
can cause the infecting microbe to be killed by lysis
prevents cleavage of complement proteins, such as C3 and C5
can cause the infecting microbe to be killed by lysis
Complement can be activated by all of the following EXCEPT __________.
antigen–antibody binding
mannose-binding lectins
opsonization
contact with a pathogen
the presence of host tissue
the presence of host tissue
Which of the following statements is NOT true of nitric oxide (NO)?
It can be produced by blood vessel endothelial cells.
It is of little value in killing microbes or tumor cells.
It can be produced by macrophages that have been induced to produce NO synthase.
Excessive production can cause septic shock.
It can cause relaxation of blood vessel smooth muscle.
It is of little value in killing microbes or tumor cells.
Assume you mix red blood cells, antibodies against the red blood cells, and complement in a test tube. What would you expect to see?
phagocytosis
agglutination of the red blood cells
opsonization of the red blood cells
shrinkage (crenation) of the red blood cells
lysis of the red blood cells
lysis of the red blood cells
Which of the following statements is NOT true of the classical pathway of complement activation?
C5b joins C6, C7, C8, and C9 to form the membrane attack complex.
C3 is the first component to be activated.
Activated C2a and C4b activate C3.
C1 is activated by an antigen–antibody complex
Activated C1 activates C2 and C4.
C3 is the first component to be activated.
Complement component C3, in the classical pathway, is split by __________.
C2bC4b
C4bC4a
C5
C2bC4a
C2aC4b
C2aC4b
Which of the following occurs first, setting in motion the remaining events?
Antimicrobial peptides (AMPs) are produced and damage microbes in a variety of ways.
Adaptive immune responses are initiated.
Toll-like receptors (TLRs) on macrophages and dendritic cells attach to pathogen-associated microbial patterns (PAMPS) on invading microorganisms.
Additional dendritic cells are attracted to the infection site by AMPs.
The macrophages and dendritic cells release cytokines.
Toll-like receptors (TLRs) on macrophages and dendritic cells attach to pathogen-associated microbial patterns (PAMPS) on invading microorganisms.
Interferons ___________.
can protect any host against any virus
are both host-specific and virus-specific
are host-specific but not virus-specific
are useful only for treating viral infections
are virus-specific but not host-specific
are host-specific but not virus-specific