Microbiology: HOST DEFENS Flashcards

1.Which is mismatched?
tumor necrosis factor - increases chemotaxis and phagocytosis
interferon alpha and beta - inhibits viral replication
prostaglandins - activate eosinophils and B cells
interleukin-2 - stimulate T cell mitosis and B cell antibody production
serotonin - causes smooth muscle contraction

2.Which is incorrect about inflammation?
Pyrogens cause vasodilation and increased capillary permeability
Fever could be beneficial to inhibiting the pathogen
Basophils and mast cells release histamine
serotonin causes smooth muscle contraction
it can last hours to years

3.All of the following are events of early inflammation, except
macrophages appear first and begin phagocytosis
exudate and pus can accumulate
chemical mediators and cytokines are released
capillaries become more permeable resulting in edema
brief vasoconstriction is followed by vasodilation

4. First line of defense may be described as
the coating of a pathogen by complement.
intact skin, mucous membranes, sebum, tears, and so forth.
nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
damage resulting in cell lysis.
the release of prostaglandins and leukotrienes in response to microbes.

5.The leukocytes called natural killer lymphocytes
are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
respond to the coating of a pathogen by complement.
release prostaglandins and leukotrienes in response to microbes.
are specialists in killing bacteria.
increase in allergies and helminth infection.

6.Which of the following statements is TRUE of eosinophils?
They produce the coating of a pathogen by complement.
They decline during allergic reaction.
They release prostaglandins and leukotrienes in response to microbes.
They are in intact skin, sebum, tears, etc.
They secrete toxins onto the surface of helminth parasites.

7.Fever is beneficial during viral infection because the higher temperature
increases vasodilation, bringing more leukocytes to the site of infection.
denatures viral proteins.
results in virus being shed in sweat.
prevents viral infection of fibroblasts.
increases the effectiveness of interferons.

8. Which of the following cells can use nonphagocytic means to kill bacteria?
natural killer cells
macrophages
eosinophils
neutrophils
both eosinophils and neutrophils

9.Which of the following statements concerning the alternative complement system is TRUE?
Its activation is independent of antibodies
It is more efficient than the classical pathway.
It plays a very significant role in the elimination of parasitic helminths.
It works best on Gram-positive bacteria.
It is not useful in the early stages of fungal infection.

10.Which of the following is the key difference in the roles of the classical and alternative pathways of the complement system?
triggering inflammation
the formation MACs
the effectiveness in killing Gram-negative bacteria
the range of microbe types that can be targeted
production of chemotactic factors.

11.The first and second lines of defense against microbial invasion are part of
innate immunity.
species resistance.
microbial antagonism.
adaptive immunity.
both species resistance and adaptive immunity.

12. How is the development of autoimmunity normally prevented?
T lymphocytes require a specific set of cytokine signals to become activated.
Regulator T cells suppress autoimmune responses.
Clonal deletion of T cells and regulatory T cell suppression prevent autoreactive T cell activation.
Clonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell suppression prevent activation of autoreactive T cells.
T lymphocytes that respond to autoantigens in the thymus undergo clonal deletion.

13.IgE antibodies are best described as
the antibodies found in body secretions.
the trigger for antibody-dependent cellular toxicity (ADCC).
a cause of basophil and eosinophil degranulation.
the most common type of antibody in the blood during the initial phases of an immune response.
those involved in complement activation.

14.Which of the following best describes IgM antibodies?
The are the most common type of antibody in the blood during the initial phases of an immune response.
They can cross the placenta to provide passive immunity.
They are the antibody class found in body secretions.
They cause basophils and eosinophils to degranulate.
They interact with phagocytes and NK cells.

15.Vaccination triggers an immune response which produces ______ immunity.
artificial passive
natural active
natural passive
artificial active
both active and passive

16-What type of immunity is produced by the body when a person contracts a disease?
naturally acquired passive immunity
innate immunity
artificially acquired active immunity
naturally acquired active immunity
artificially acquired passive immunity

17-Which of the following statements regarding the cell-mediated immune response is TRUE?
A single cytotoxic T lymphocyte can kill many target cells.
Cytotoxic T lymphocytes do not require antigen presentation to become activated.
Cytotoxic T lymphocytes kill be producing hydrogen peroxide.
Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes.
Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their target.

18-Which of the following statements concerning B cell receptors (BCRs) is FALSE?
They are bound to the surface of B lymphocytes and have two antigen-binding sites.
They are complementary in shape to a specific antigenic determinant that they may or may not encounter.
Scientists estimate that each person forms at least 1011 different types of B lymphocytes with distinct BCRs.
They are formed in response to an encounter with an antigen.
Each B lymphocyte is randomly generated with antibody variable regions that determine its BCR

19.Which of the following function(s) in agglutination?
IgD antibodies
IgG antibodies
IgA antibodies
IgE antibodies
IgA and IgG antibodies

20.The type of immunoglobulin illustrated here is
IgD
IgA
IgG
IgE
IgM

21.The white blood cells primarily responsible for adaptive immunity are
NK lymphocytes and neutrophils
neutrophils and dendritic cells
B lymphocytes and T lymphocytes
macrophages and eosinophils
macrophages and neutrophils

22.All of the following are characteristics of an effective vaccine except
it should not require numerous boosters.
it should protect against wild forms of the pathogen.
it should stimulate only the antibody (B-cell) response.
it should be easy to administer.
it should have a relatively long shelf life.

23.Which process involves antibodies cross-linking cells or particles into large aggregates?
Anamnestic response
Complement fixation
Agglutination
Neutralization
Opsonization

24-Which process involves antibodies coating microorganisms in order to facilitate phagocytosis?
Complement fixation
Agglutination
Neutralization
Anamnestic response
Opsonization

25 antigens converts these into plasma

26- involved in cell-mediated immunity

27- directed against transplanted tissue cells and cancer cell

28-Involved in allergic reactions, such as high fever

29-based on antibodies produced as a result of recovery from disease

30- Passed to a fetus by transplacental transfer

31-Passed to an infant in human colostrum

32- passed to a recipient by injection of gamma globulin blood fraction from other people.

33- based on production of antibodies by vaccination

34-chemical messenger by which cells of the immune system communicate with each other

35- the relative strength of the antigen- antibody bond

36- A pentamer; the first antibody class to appear, though comparatively short-lived

37-The most abundant immunoglobulin in serum

38-Functions of the immunoglobulin class are not well defined, but it is found on the surface of B cells

39- often forms dimer of 2 immunoglobulin monomers

40- B cells that interact with self-antigens are destroyed.

41-Present T-dependent antigens to B cells

42- recognize and target cells that carry endogenous antigens

43-Requires assistance of the a T-helper cell to form antibodies.

44-Typically a protein

45-Cytokine that inhibits viral infections

46-released by cytotoxic T lymphocyte to lyse a target cell

47-stem region of an antibody molecule

48-Programmed cell death

49-Adjective applied to the cells that actually produce antibodies after a B cells is stimulated by antigen

50- Clumping of antigens when biding with antibodies

51- coating of antibodies that enhances phagocytosis

52- resistance present at birth that does not involve humoral or cell-mediated immunity is --- immunity

53- Induce migration of leukocytes into areas of infection

54-Certain lymphocytes called---cells killer virus-infected cells and tumor cells. but are not immunologically specific. They contact and kill the target cells

55-An antigen-presenting cell (APC) that is not efficient at phagocytosisi, but is the most important in APC, is called a ---

56-Antigen converts these into plasma cells.

57-Involved in cell-mediated immunity.

58-Responsible for rejection of foreign tissue transplants.

59-Directed against transplanted tissue cells & cancer cells.

60-Have been influenced by the thymus.

61-Defend mainly against bacteria & viruses circulating in blood & lymph.

62-Based on antibodies produced as a result of recovery from a disease.

63-Passed to fetus by transplacental transfer.

64-Passed to recipient by injection of gamma globulin blood fraction from other people.

65-Based on production of antibodies by vaccination.

66-An incomplete antigen that will react w/antibodies but will not, by itself, stimulate their formation.

69-Chemical messengers by which cells of immune system communicate w/each other.

70-The relative strength of the antigen-antibody bond.

71-A pentamer; the first antibody class to appear, though comparatively short-lived.

72-The most abundant immunoglobulin in serum.

73-Functions of this immunoglobulin class are not well defined, but it is found on the surface of B cells.

74-Involved in allergic reactions, such as hay fever.

75-Often forms dimers of 2 immunoglobulin monomers.

76-Synonym for antigens.

77-B cells that interact w/self-antgens are destroyed.

78-Protein bound to IgA immunoglobulins.

79-Blood fration that contains most of the serum immunoglobulins.

80-Activated B cell proliferates into a large clone of cells, some of which will differentiate into plasma cells.

81-CD4+

82-CD8+

83-Can differentiate into CTLs.

84-Requires assitance of a T helper cell to form antibodies.

86-Typically a polysaccharide such as a bacterial capsule.

87-Cytokine that inhibits viral infections.

88-Released by a cytotoxic T lymphocyte to lyse a target cell.

89-Coating of target cell w/antibody that enhances phagocytosis.

90-Coating of target cell w/antibody that leads to lysis by substances secreted by immune cells external to the target cell.

91-Releative amont of antibody in the serum.

92-Communicate between leukocytes.

93-A factor in inflammatory diseases such as rheumatoid arthritis.

94-Control pathways by which stem cells develop into different red or white blood cells.

95-Induce migration of leukocytes into areas of infection.

96-Resistance present at birth that does not involve humoral or cell-mediated immunity is ____________________________ immunity.

97-The five monomers that constitute the IgM molecule are held together by a ________________.

98-Certain lymphocytes called ________ cells kill virus-infected cells & tumor cells, but are not immunologically specific. They contact & kill the target cells.

99-B cells derive their name from an organ in poultry, the ___________.

100-Low-molecular-weight substances such as penicillin that do not (by themselves) cause formation of antibodies are known immunologically as ___________.

101-The second time we encounter an antigen, our immune response is faster & more intense; this is termed the ______ response.

102-Recognize & target cells that carry endogenous antigens.