ch. 43 part 2 Flashcards

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1
Q

cytokines are released from the ________ to activate the helper T cell

A

macrophage/dendritic cell

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2
Q

activation of B cell in humoral response

A
  1. entered antigen taken in by receptor-mediated endocytosis
  2. MHC 2 presents antigen on B cell surface
  3. activated helper T cell recognizes antigen and releases cytokines
  4. activated B cell divides into memory and plasma cells
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3
Q

plasma B cells

A

secrete antibodies that go out and identify/mark foreign pathogen

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4
Q

how many antibodies does each plasma cell release

A

over a trillion over 4-5 days
- 2,000 per second

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5
Q

what do antibodies do

A

mark pathogens for inactivation/destruction
- don’t kill them

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6
Q

3 processes performed by antigens

A
  1. neutralization
  2. opsonization
  3. antigen-antibody complex
  4. agglutination
  5. precipitation
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7
Q

neutralization

A

antibodies bind to viral surface proteins, preventing infection of a host cell

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8
Q

opsonization

A

antibodies bind to antigens on bacteria, triggering phagocytosis

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9
Q

positive feedback system of opsonization

A
  • dendritic cells/macrophages present antigens on surface to become antigen-presenting cells
  • stimulates humoral immunity
  • opsonization enhances antigen presentation and humoral immunity
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10
Q

antigen-antibody complexes

A

may bind to complement protein, which triggers cascade of complement protein activation to form membrane attack complex

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11
Q

membrane attack complex

A

forms pore in the membrane of the foreign cells, leading to its lysis

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12
Q

how can humoral immunity kill infected cells

A
  • viral infected cells often display part of virus on infected cell surface
  • if antibodies specific for epitopes on these viral fragments, they bind to viral proteins
  • natural killer cells induce infected cells to undergo apoptosis
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13
Q

agglutination

A

antibodies often have 2 receptor sites for antigens on pathogens, and binds to 2 antigens. this creates a clump, which is easier to engulf by macrophages

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14
Q

precipitation

A

binds to free-floating antigens and clumps them together, which are then engulfed by macrophage

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15
Q

how many different forms/classes of immunoglobulins can B cells express

A

5

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16
Q

different forms of immunoglobulins

A
  • similar antigen-binding specificity
  • different heavy chain C regions
  • IgD is membrane bound
  • IgA, IgE, IgG, and IgM are soluble
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17
Q

cytotoxic T cells

A

use toxic proteins to kill cells infected by viruses or other intracellular pathogens

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18
Q

what do cytotoxic T cells recognize

A

fragments of foreign proteins produced by infected cells

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19
Q

what does an activated cytotoxic T cell secrete

A

proteins that disrupt membranes of target cells and trigger apoptosis

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20
Q

CD8 protein function

A

between cytotoxic T cell and virus-infected cell, determines if infected cell needs to be killed or not
- helps recognize if class I MHC

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21
Q

what does cytokines interleukin 2 do

A

stimulates production of specialized helper T cells and cytotoxic T cells to eliminate threat

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22
Q

what tells the cytotoxic T cell to kill an infected cell

A

signal from helper T cell attached to macrophage

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23
Q

what is released in the gap between the cytotoxic T cell and infected cell

A

vesicles containing perforins

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24
Q

what do perforins do

A

create channels that allow water to rush into the cell

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25
Q

how are viruses eliminated

A

through humoral response (antibodies/opsonization) and through cell-mediated cytotoxic response

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26
Q

basis of immunization

A

projection provided by second immune response

27
Q

why are antigens artificially introduced into the body?

A

to generate adaptive immune response and memory cell formation

28
Q

how are immunizations carried out

A

vaccines - preparations of antigens from many sources

29
Q

active immunity

A

develops naturally when a pathogen invades the body and elicits a primary or secondary immune response
- actually exposed to antigen

30
Q

passive immunity

A

provides immediate, short-term protection
- conferred naturally when IgG crosses placenta from mother to fetus or when IgA passes from mother to infant in breast milk

31
Q

ex. of natural active immunity

A

infection

32
Q

ex. of artificial active immunity

A

vaccination

33
Q

ex. of natural passive immunity

A

maternal antibodies

34
Q

ex. of artificial passive immunity

A

monoclonal antibodies
- antibodies from immune animal injected into a non immune animal

35
Q

what are antibodies produced by an animal after exposure to an antigen products of

A

different clones of plasma cells

36
Q

monoclonal antibodies

A

can be prepared from single clone of B cells grown in culture
- identical
- specific for 1 epitope
- used in many types of medical diagnoses

37
Q

why are blood transfusions and tissue transplants sometimes complicated?

A

cells transferred from one person to another can be attacked by immune defenses

38
Q

what is done to minimize rejection of a transplant or graft?

A
  • use donor tissue with MHC molecules as similar as possible to the recipient
  • recipient takes medicines that suppress immune responses
39
Q

antigens on red blood cells

A
  • A - A antigen
  • B - B antigen
  • AB - A and B antigens
  • O - neither antigen
40
Q

what kind of blood antibodies exist in the body

A

antibodies to non self blood types

41
Q

allergies

A

hypersensitive (exaggerated) responses to antigens called allergens

42
Q

localized allergies

A
  • IgE antibodies produced after first exposure to allergen attach to receptors on mast cells
  • next time allergen enters body, it binds to mast-cell-associated IgE molecules
  • mast cells release histamine/inflammatory chemicals that bring about typical allergy symptoms
43
Q

acute allergic response

A

can lead to anaphylactic shock within seconds of allergen exposure

44
Q

anaphylactic shock

A

life-threatening reaction

45
Q

what can counteract an allergic response

A

injection of epinephrine

46
Q

autoimmune disease

A

immune system loses tolerance for self and turns against certain molecules of body

47
Q

ex. of autoimmune diseases

A
  • lupus erythematosus
  • rheumatoid arthritis
  • insulin-dependent diabetes mellitus
  • multiple sclerosis
48
Q

exercise and immune system function

A
  • moderate - improves function
  • exhaustion - leads to frequent infections
49
Q

effect of psychological stress on immune system

A

disrupts it by altering interactions of hormonal, nervous, and immune systems

50
Q

inborn immunodeficiency diseases

A

result from genetic or developmental defect in innate/adaptive defenses

51
Q

acquired immunodeficiency diseases

A

develops later in life due to exposure to chemical/biological agents

52
Q

how are some pathogens able to prevent recognition

A

change epitope expression through antigenic variation

53
Q

human influenza virus

A
  • mutates rapidly
  • new flu vaccines made each year
54
Q

what do human viruses often exchange genes with?

A

viruses of domesticated animals
- human immune systems then unable to recognize new viral strain

55
Q

latency

A

inactivate state of some viruses in a host

56
Q

herpes simplex viruses

A

can be present in a human host without causing symptoms

57
Q

human immunodeficiency virus (HIV)

A
  • infects helper T cells
  • high mutation rate that promotes antigen variation - persists in host
58
Q

what happens over time to untreated HIV infection

A

avoids adaptive immune response and abolishes it

59
Q

what does HIV infection lead to

A

acquired immunodeficiency syndrome (AIDS)

60
Q

AIDS symptoms

A

highly susceptible to opportunistic infections and cancers that a normal immune system would usually defeat

61
Q

how does the frequency of certain cancers increase

A

when adaptive immunity is inactivated

62
Q

what percent of human cancers involve viruses

A

15-20%

63
Q

what is human papilloma virus associated with

A

cervical cancer