Immune System 2 Flashcards
1
Q
B lymphocyte exposure to antigen triggers _____ _____.
A
clonal selection
2
Q
What is the life span of plasma cells?
A
4-7 days
3
Q
Plasma cells secrete ______ antibodies specific for antigen per second.
A
2000
4
Q
What is the role of antibodies in plasma cells?
A
circulate for weeks, binding to and marking antigen for destruction
5
Q
What is the mechanism of the antibodies in plasma cells?
A
- phagocytosis
- complement-mediated lysis
6
Q
Sometimes proliferation and differentiation of B cells in response to antigen depends on ____ ___ ____.
A
helper T cells
7
Q
Antigens are ________ antigens.
A
T-dependent
8
Q
Helper T cells respond to what.
A
specific antigen
9
Q
Helper cells secrete:
A
IL-2 (among other cytokines)
10
Q
What activates B cells?
A
IL-2 + T-dependent antigens
11
Q
What happens in the absence of T cells?
A
- B cells can proliferate and differentiate into plasma cells (not memory cells)
- Response weaker than helper T cell–dependent response
- No memory for subsequent exposures
12
Q
Describe antibody functions in humoral immunity.
A
- Binds to specific antigen
- Aids in inactivation or destruction of antigen
13
Q
Describe antibody actions in humoral immunity.
A
- Immunoglobins
- All classes: neutralization and agglutination
14
Q
What is the role of IgM and IgG?
A
activate complement
15
Q
What is the role of IgG?
A
opsonization
16
Q
What is the role of IgE?
A
histamine release from mast cells and basophils
17
Q
What is the role of NK cells?
A
- NK cells have receptors for the antibody tail
- Antibodies mark cells for destruction
- NK cells produce pores in the membranes of cells, causing lysis
18
Q
Name 5 antibody-mediated mechanisms of antigen disposal.
A
- neutralization
- agglutination
- opsonization
- complement activation
- enhanced NK cell activity
19
Q
Describe neutralization.
A
antibodies block the activity of a pathogen
20
Q
Describe agglutination.
A
multiple pathogens are aggregated by antibody molecules
21
Q
Describe opsonization.
A
pathogens bound by antibodies are more efficiently engulfed by phagocytes
22
Q
Describe complement activation.
A
antibodies bound to pathogens activate the complement cascade, resulting in lysis of the cell
23
Q
Describe enhanced NK cell activity.
A
abnormal body cells that are bound by antibodies are recognized by NK cells and are subsequently lysed
24
Q
What role does helper T cells have in cell-mediated immunity?
A
- Secrete cytokines that enhance activity of B cells and other T cells
- Enhance activity of macrophages and NK cells
25
What role does cytotoxic T cells have in cell-mediated immunity?
- Kill virus-infected cells, abnormal cells, and bacteria
| - Suppressor T cells secrete cytokines that suppress activity of B cells and other T cells
26
What does MHC stand for?
major histocompatibility complex
27
MHC marks body cells as ____, and is a ____ type.
- self
| - tissue
28
What are the 2 classes of MHC molecules?
- Class I MHC
| - Class II MHC
29
Describe class I MHC molecules.
surface of all nucleated cells
30
Describe class II MHC molecules.
surface of macrophages, activated B cells, activated T cells, and thymus cells
31
Why is MHC molecules unique to individual person?
human leukocyte antigen (HLA)
32
MHC molecules are responsible for ______ or _____ rejection, and stimulates immune response to foreign tissue.
tissue or organ
33
MHC molecules have binding sites for _____.
antigen
34
MHC + antigen =
cell surface (presentation)
35
WHat does type I MHC do?
bind antigens in infected cells or tumor cells (which can be any nucleated cell)
36
What does type II MHC do?
Bind antigens taken into cell by phagocytosis
or receptor-mediated endocytosis (which can occur only in cells that perform these functions—B cells, T cells, macrophages)
37
Final maturation of T cells depends on:
contact with MHC molecules
38
T cells become ______ or _____.
helper or cytotoxic
39
Helper T cells coordinate the _____ ____.
immune response
40
Describe the steps of helper T cells activation.
- Bind to surface of macrophages and B cells
| - Macrophages and B cells secrete cytokines, which induces proliferation and differentiation of helper T cells
41
How are cytotoxic T cells activated?
- Cell binds to antigen complex on infected/tumor cell
- Helper T cell secretes cytokines
- Activates cytotoxic T cell
42
What 2 things do the cytotoxic T cells secrete?
- perforins for lysis
| - fragmentins for apoptosis
43
Define vaccine.
introduction of microorganism or its antigens in a form not expected to cause disease
44
What is the response from vaccine?
Induces immune response, including production of memory cells
45
What is active immunity? Give an example.
- immune response to vaccine or pathogen in individual gives immunity
- vaccination
46
What is passive immunity? Give an example.
- administration of ready-made antibodies
- no memory cells, so no long-term immunity
- passive immunity from mother to fetus or baby
47
Describe passive immunity from mother to fetus or baby.
- IgG passes to fetus via the placenta
| - IgA passes to baby in breast milk
48
What happens during organ matching?
- need to match donor to recipient closely
| - must suppress immune system in recipient
49
What inhibits molecules that enhance abnormal cell recognition? What do they do?
- some cancers and viruses
| - protects them from the immune system
50
Blood type A can accept what types?
A and O
51
Blood type B can accept what types?
B and O
52
Blood type AB can accept what types?
A, B, AB, and O
53
What is the universal recipient?
AB+
54
Blood type O can accept what types?
O
55
What is the universal donor?
O
56
What antibodies are in the plasma of type A?
anti-B
57
What antibodies are in the plasma of type B?
Anti-A
58
What antibodies are in the plasma of type AB?
none
59
What antibodies are in the plasma of type O?
- anti-A
| - anti-B
60
What antigens are in the RBC of type A?
A antigen
61
What antigens are in the RBC of type B?
B antigen
62
What antigens are in the RBC of type AB?
A and B antigens
63
What antigens are in the RBC of type O?
none
64
Describe what happens during tissue grafts and organ transplantation.
- "self" molecules induce an immune response to foreign cells
- tissue typing (suppression of recipients immune system)
65
How does radiation affect the immune system?
destroys bone marrow cells, inactivating immune system
66
Why are some bone marrow transplants more successful than others?
Donated marrow may mount an immune response against recipient: graft versus host reaction
67
In transplants, it is necessary to match donor and recipient ___ molecules.
HLA
68
What is tissue typing?
matching HLA molecules between donor and recipient
69
What is an allergy?
hypersensitive immune response
70
What are allergens?
antigens that induce allergic reactions
71
What happens during a allergic response?
- Excess antibodies (immunoglobins—IgE), attach to mast cells vs just binding to pollen (antigen)
- Antibodies activate mast cells
- Histamine released
- vasodilation, increased capillary permeability
72
What is anaphylactic shock?
sever allergic reaction
73
What happens physiologically during anaphylactic shock?
- Massive release of histamine from mast cells throughout the body
- Vasodilation → decreased TPR → decreased MAP
- Prophylactic: epinephrine
Increases CO and TPR → increased MAP
74
What happens with autoimmune diseases?
- Immune system treats a part of self like a pathogen
| - Immune response is induced against that part
75
Give examples of autoimmune diseases.
- Insulin-dependent diabetes mellitus
- Lupus
- Rheumatoid arthritis
- Multiple sclerosis
76
What happens with immunodeficiency diseases?
- Weak or underactive immune system
| - A problem in any factors of immune response can impair immune function
77
Give examples of immunodeficiency diseases.
- severe combined immunodeficiency disease (SCID)
- Hodgkin's disease
- AIDS
78
What is affected in SCID?
humoral and cell-mediated immunity
79
Hodgkin's diseases is cancer of ______ system.
lymphatic
80
AIDS affects what?
helper T cells
81
Stress does what to the immune system?
suppresses
82
What systems are affected by stress?
- nervous
- endocrine
- immune
83
What does cortisol do?
- decrease number of leukocytes
| - anti-inflammatory activity
84
What is the open window theory?
after intense exercise there is increased susceptibility to illness
85
What is the "open window"?
3-72 hours
86
Explain the open window theory.
- WBC #”s increase during and after (moderate), but fall below pre exercise values with intense, prolonged exercise (ie. Neutrophils)
- Lymphocytes increase during, but #’s fall after (below pre exercise values) with incr. intensity and duration of exercise
- Decreased antibody numbers after prolonged, intense exercise
- Increased lymphocyte apoptosis
87
Based on the response from the open window theory, what can we do?
stop performing heavy intensity exercise?
