Microbiology Chapter 16 Innate Immunity Flashcards

Cells produce alpha interferon and beta interferon in response to __________.

a. helminthic infections

b. protozoan infections

c. viral infections

d. bacterial infections

Which of these cells do NOT have phagocytic activity?

a. eosinophils

b. neutrophils

c. lymphocytes

d. macrophages

Which complement protein directly forms the membrane attack complex (MAC)?

a. C3

b. C5

c. C1

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

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.

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

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

__________ 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

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

__________ 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

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

Which type of leukocyte is the most abundant in blood?

a. lymphocytes

b. eosinophils

c. monocytes

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.

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

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

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.

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

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.

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

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

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

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

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

Antibodies are produced by _________________.

a. cytotoxic T cells

b. phagocytes

c. B cells

d. helper T cells

A leukocyte with visible granules in the cytoplasm when viewed through a light microscope; includes neutrophils, basophils, and eosinophils.

The number of each kind of leukocyte in a sample of 100 leukocytes.

A food vacuole of a phagocyte; also called a phagocytic vesicle.

Small peptide antibiotics made by human cells.

The microorganisms that colonize a host without causing disease; also called normal flora.

The process by which phagocytes move out of blood vessels.

An enzyme capable of hydrolyzing bacterial cell walls.

A small protein released from human cells that regulates the immune response; directly or indirectly may induce fever, pain, or T cell proliferation.

The process by which phagocytes stick to the lining of blood vessels.

A localized accumulation of pus.

A group of serum proteins involved in phagocytosis and lysis of bacteria.

A macrophage that is located in a certain organ or tissue (e.g., liver, lungs, spleen, or lymph nodes); also called a histiocyte.

A granulocyte (leukocyte) that readily takes up basic dye and is not phagocytic; has receptors for IgE Fc regions.

Chemicals that promote growth of beneficial bacteria in the body.

An antibiotic that is bactericidal and has a broad spectrum of activity; see bacteriocin.

Microbes inoculated into a host to occupy a niche and prevent growth of pathogens.

An abnormally high body temperature.

Ciliated mucosal cells of the lower respiratory tract that move inhaled particulates away from the lungs.

A lymphoid cell that destroys tumor cells and virus-infected cells.

See mononuclear phagocytic system.

The formation of blood cells.

An appendage on a bacterial cell used for attachment.

A leukocyte that is the precursor of a macrophage.

An extension of a eukaryotic cell that aids in locomotion and feeding.

A leukocyte without visible granules in the cytoplasm when viewed through a light microscope; includes monocytes and lymphocytes.

Protein that makes a pore in a target cell membrane, released by cytotoxic T lymphocytes.

Molecules present on pathogens and not self.

The living together of two different organisms or populations.

The ability to ward off diseases through innate and adaptive immunity.

A type of lymphocyte; differentiates into anti-body-secreting plasma cells and memory cells.

A substance released from tissue cells that cause vasodilation.

A leukocyte involved in specific immune responses.

The ability, obtained during the life of the individual, to produce specific antibodies and T cells.

A protein made in response to interferon that blocks viral multiplication.

Attachment of a microbe or phagocyte to another's plasma membrane or other surface.

The inner portion of the skin.

Carbohydrate-binding proteins on a cell, not an antibody.

The enhancement of phagocytosis by coating microorganisms with certain serum proteins (opsonins); also called immune adherence.

Molecules on T cells that recognize antigens.

A white blood cell.

Complement proteins C5-C9, which together make lesions in cell membranes that lead to cell death.

A host response to tissue damage characterized by redness, pain, heat, and swelling; and sometimes loss of function.

A phagocytic cell; a mature monocyte. See fixed macrophage, free wandering macrophage.

A rapid screening test to detect the presence of antibodies against Treponema pallidum. (VDRL stands for Venereal Disease Research Laboratory.)

The ingestion of particles by eukaryotic cells.

An accumulation of dead phagocytes, dead bacterial cells and fluid.

A macrophage that leaves the blood and migrates to infected tissue.

A substance released by tissue cells that causes vasodilation, capillary permeability, and smooth muscle contraction.

The phase of a fever characterized by vasodilation and sweating.

A digestive vacuole

Proteases that include apoptosis.

The outer portion of the skin.

Host defenses that afford protection against any kind of pathogen. See also adaptive immunity.

A highly phagocytic granulocyte; also called polymorphonuclear leukocyte (PMN) or polymorph.

A hormone like substance that is released by damaged cells, intensifies inflammation.

A cell capable of engulfing and digesting particles that are harmful to the body.

An abnormal accumulation of interstitial fluid in tissues, causing swelling.

Serum proteins whose concentration changes by at least 25% during inflammation.

A mammalian organ responsible for maturation of the immune system.

An enzyme that activates another protein by adding a P from ATP.

The type of RNA molecule that brings amino acids to the ribosomal site where they are incorporated into proteins.

Bacterial iron-binding proteins.

A system of fixed macrophages located in the spleen, liver, lymph nodes, and red bone marrow.

The destruction of cells, resulting from damage to their cell membrane, that causes cellular contents to leak out.

A granulocyte whose granules take up the stain eosin.

Membranes that line body openings, include the intestinal tract, open the exterior; also called mucosa.

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.

See neutrophil.

A substance produced by mast cells and basophils that cause increase permeability of blood vessels and helps phagocytes attach to pathogens.

Dilation or enlargement of blood vessels.

Inflammation is categorized as which line of defense?

Which of the following are involved in the adaptive immune response?

Which of the following would be considered a defense against a bacterial pathogen?

mucous membranes

skin

cytotoxic cells

all of the above

Which of the following would be involved in defending the body against all pathogens?

Which of the following are involved in host surveillance of pathogens?

antibodies

phagocytes

cytotoxic T-cells

all of the above

none 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.

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

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.

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.

What is the function of leukocidins?

How might Neisseria inactivate host defenses?

How do superantigens help a pathogen survive?

Which pathogen would use immune system suppression to evade destruction by the host?

Which of these molecules or structures is/are NOT associated with innate immunity?

macrophages

lysozyme

phagocytes

mucous membranes

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

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

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

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.

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

Which of these structures are NOT part of the mononuclear phagocytic system?

lymphocytes

Kupffer's cells

alveolar macrophages

microglial cells

wandering macrophages

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.

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.

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

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.

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.

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

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

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.

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

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.

Complement component C3, in the classical pathway, is split by __________.

C2bC4b

C4bC4a

C5

C2bC4a

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.

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