Immunity Flashcards
1
Q
Cells of the immune system:
A
- neutrophils
- basophils
- eosinophils
- monocytes
- lymphocytes
2
Q
Neutrophils are…
A
phagocytes
3
Q
Eosinophils destroy…
A
parasites
4
Q
Basophils release…
A
- histamines
- leukotrienes
- prostaglandins
5
Q
Monocytes are…
A
macrophages/phagocytes
6
Q
Types of lymphocytes:
A
- B lymphocyte
- T lymphocyte
7
Q
Why would there be an abundance of neutrophils?
A
bacterial infection
8
Q
Why would there be an abundance of lymphocytes?
A
viral infection
9
Q
Why would there be an abundance of eosinophils?
A
allergic response
10
Q
Immune system provides…
A
resistance to disease
11
Q
Immune system is made up of two intrinsic systems. What are they?
A
- innate (nonspecific)
- adaptive (specific)
12
Q
Innate system are part of which lines of defense?
A
first and second lines of defense
13
Q
First line of defense for innate system are…
A
external body membranes (physical barriers)
- skin
- mucosae
14
Q
Second line of defense for innate system are…
A
- antimicrobial proteins
- phagocytes
- inhibit spread of invaders
- inflammation is most important
15
Q
Adaptive system:
A
3rd line of defense
- attack specific foreign substances
16
Q
What are the two categories of lymphoid categories?
A
- primary: sites where stem cells divide and develop
- secondary: sites where most immune responses occur
17
Q
What are lymphoid organs?
A
places where immune cells hang out
18
Q
Examples of primary lymphoid organs:
A
- bone marrow
- thymus
19
Q
Function of bone marrow:
A
produces mature B cells and immature T cells
20
Q
Thymus is a primary lymphoid organ because…
A
- where T cells mature
- has T cells, scattered dendritic cells, epithelial cells, and macrophages
21
Q
Thymus:
A
- located above heart
- atrophies after maturity
22
Q
Examples of secondary lymphoid organs:
A
- lymph nodes
- spleen
- lymphoid nodules
23
Q
Function of lymph nodes:
A
- filter microbes
- macrophages and lymphocytes destroy filtered microbes
24
Q
Where are lymph nodes located?
A
scattered throughout lymphatic vessels of body
25
Function of spleen:
removes microbes and aged/defective erythrocytes
26
The spleen is the largest...
lymphoid organ
27
Examples of lymphoid nodules:
- tonsils
- peyer's patches
- appendix
28
Innate immunity is the ability of the body to defend itself against...
microbes and other foreign substances without specific recognition of invading pathogens
29
Innate immunity: function of skin in 1st line defense
- water resistant
| - prevents entry of foreign substances
30
Innate immunity: examples of other physical barriers than skin for 1st line of defense
- mucus
- hair
- cilia
- sebum
- lysozyme
- gastric juice
- vaginal secretions
31
2nd line of defense for innate immunity comes into play when...
first line is not effective
32
Innate immunity (2nd line): function of antimicrobial substances
discourage microbial growth via interferons, complement, iron-binding proteins, or antimicrobial proteins
- attack microorganisms directly or hinder its ability to reproduce
33
Innate immunity (2nd line): function of natural killer cells
release chemicals that lead to death of infected or abnormal body cells
34
Innate immunity (2nd line): function of phagocytes
- neutrophils and macrophages non-specifically engulf microbial invaders
35
Innate immunity (2nd line): steps of phagocytosis
1. adherence: recognition and attachment
2. ingestion
3. digestion via fusion w/ lysosome
4. killing and degradation via O2 radicals
36
Innate immunity (2nd line): inflammatory response
- nonspecific response to tissue damage
- rids body of organisms that caused tissue damage and damaged tissues
- promotes wound healing
37
Causes of inflammation:
- trauma
- chemical agents
- thermal extremes
- pathogenic organisms
38
What is the most abundant phagocyte?
neutrophils
39
Neutrophils are aided by...
opsonization: antibodies/complement proteins as opsonin that coat pathogens and make them easier to phagocytose
40
Macrophages develop from...
monocytes and are the chief phagocytic cells
41
Free macrophages:
wander through tissue spaces
| - ex: alveolar macrophages
42
Fixed macrophages:
permanent residents of some organs
| - ex: stellate macrophages (liver) or microglia (brain)
43
Helper T cells trigger macrophage to...
produce respiratory burst, which kills pathogens resistant to lysosomal enzymes by releasing free radicals, producing oxidizing chemicals, and increasing pH and osmolarity of phagolysosome
44
Symptoms and signs of inflammation:
- fever (pyrogenesis)
- redness (rubor)
- swelling (turgor)
- pain (dolor)
- tissue/organ dysfunction (functio laesa)
45
Sequence of inflammatory events:
1. trauma or pathogen leads to acute inflammatory response
2. platelet adhesion and vasoconstriction of efferent vessels
3. cytokine induced afferent vascular dilation
4. activation of complement, clotting, fibrinolysis, kinin system, leukocyte adhesion cascade
5. endothelial gaps
46
Cytokine induced afferent vascular dilation leads to...
increased blood flow to infected/damaged area
47
Endothelial gaps increase...
vascular permeability and allow extravasation of serum proteins and leukocytes
48
Natural killer cells are...
- nonphagocytic
- large granular lymphocytes
- part of 1st line of defense
49
Function of natural killer cells:
- police blood and lymph
- kill cancer and virus-infected cells before adaptive immunity is activated
- attack cells that lack "self" receptors
- secrete potent chemicals that enhance inflammatory response
50
Natural killer cells kill by inducing...
apoptosis in cancer cells and virus-infected cells
51
Benefits of inflammation:
- prevents spread of damaging agents
- disposes of cell debris and pathogens
- alerts adaptive immunity
- sets stage for repair
52
During inflammatory chemical releases, macrophages have...
special pattern recognition receptors called toll-like receptors (TLRs), which trigger release of cytokines that promote inflammation
53
Kinins, prostaglandins (PGs), and complement:
- causes vasodilation of local arterioles
- make capillaries leaky
- attract leukocytes to area
- trigger pain receptors
- prompting release of more inflammatory chemicals
54
Vasodilation and increased vascular permeability leads to...
- hyperemia
- redness
- heat
55
Benefits of edema:
- sweeps foreign material into lymphatic vessels for processing in lymph nodes
- delivers clotting proteins and complement to area
56
Basics of acute inflammation:
1. vasodilation
2. increased flow to damaged area
3. repair
57
Acute inflammation: effects of vasodilation
- increased vascular permeability and edema
- allows more blood flow to site
- causes loss of plasma proteins
- permeability changes caused by histamine and kinins
58
Acute inflammation: increased flow to area increases...
emigration: WBC population goes to damaged site to deal with what is causing response
59
Acute inflammation: increased flow to area occurs via...
chemotaxis: chemically stimulated movement of phagocytes
| - chemoattractants: chemicals that attract phagocytes
60
Acute inflammation: phagocytes move across capillary wall via...
diapedesis
61
Acute inflammation: repair occurs once infection has...
been contained or cleared
| - can leave scar tissue (collagen fibers more densely arranged)
62
Clinical presentations of infection:
- pus
- abscess
- tumorlike growth
63
Pus looks like...
creamy yellow mixture of dead neutrophils, tissue/cells, and living/dead pathogens
64
Abscess are...
collagen fibers that are laid down, which walls off sac of pus
- might need to be surgically drained
65
Tumorlike growth (granulomas) occurs b/c of...
bacteria's ability to resist to digestion by macrophages and stay alive
66
Most important antimicrobial proteins are...
- interferons
| - complement proteins
67
Interferons are cells that are...
infected with viruses and can secrete IFNs that warn healthy neighboring cells
68
Chemical cascade includes...
eicosanoids, such as prostaglandins and leukotrienes
69
What is a complement system?
group of 20 blood proteins that circulate blood in inactive form
70
Complements are present in...
- plasma
| - on cell surfaces
71
Complements interact w/...
each other to produce biologically active inflammatory mediators
72
The complement cascade leads to...
- chemotaxis (C5a)
- inflammation (C3a)
- increased capillary permeability (C5a)
- opsonization (C3b)
- cytolysis
73
Complement cascade is a series of...
enzymatic reactions
74
Opsonization is the...
promotion of phagocytosis
75
What are the three pathways to activate phagocytes?
- classical
- lethal binding
- alternate
76
Describe the classical pathway of activation for phagocytes:
most specific
- antibody dependent activation
- binds C1
77
Describe the lethal binding pathway of activation for phagocytes:
some specificity
- mannose binding protein
- binds C4
78
Describe the alternate pathway of activation for phagocytes:
most primitive
- nonspecific
- auto-activation of C3
79
T/F: nitric oxide from blood vessels and macrophages don't contribute to inflammation
F, they do contribute
80
When tissue is destroyed or invaded by leukocytes in inflammation for pain, what happens?
mediators are delivered by circulation and/or released
81
Examples of proalgesic mediators:
- proinflammatory cytokines
- chemokines
- protons
- nerve growth factor
- prostaglandins
82
Proalgesic mediators are produced by...
invading leukocytes or by resident cells
83
Proalgesic mediators can produce...
- analgesic mediators, which counteract pain
- anti-inflammatory cytokines
- opioid peptides
84
Role of NSAIDs and aspirin in inflammation:
- prevent cyclooxygenase from making prostaglandins
| - reduce inflammation
85
T/F: cytokines are produced in inflammatory response
T, because they promote inflammation
86
Fever is a systemic response to...
invading microorganisms
87
What are the benefits for a fever?
- intensifies interferon effect
- inhibits growth of some microbes
- speeds up body repair processes
- liver and spleen to sequester iron and zinc, which are needed by microorganisms
88
Which molecules are involved in a fever?
- leukocytes
| - macrophages
89
What activates the leukocytes and macrophages during a fever?
foreign substances
90
When leukocytes and macrophages are exposed to foreign substances, they secrete...
pyrogens, which reset thermostat in hypothalamus
91
Adaptive immunity develops..
after exposure to antigen
| - allows macrophages to show lymphocytes what to look for
92
Adaptive immunity is regulated by...
release of lymphokines and interleukins
93
Lymphocytes are activated by...
acquiring disease or by vaccination
94
Adaptive immunity amplifies _____ and activates _____
inflammatory response, complement
95
Disadvantage of adaptive immunity:
has to be primed by initial exposure to specific foreign substance, which takes time
96
T/F: adaptive immunity doesn't have memory
F, it does for previously encountered antigens
97
What are the important components of adaptive immunity?
- B and T cells, which are both lymphocytes
- antigen presenting cells (APCs), which don't respond to specific antigens and play essential auxiliary roles in immunity
98
B and T cells both must...
- gain immunocompetence
| - develop antigen receptors
99
B cells produce...
antibodies
100
Types of T cells:
- cytotoxic T cells (CD8)
| - helper T cells (CD4)
101
Humoral immunity is...
antibody mediated adaptive immunity
102
What is the immune component in humoral immunity?
- antibodies (gamma globulins) that travel in plasma
103
Antibodies are made by ____ and mature in ____
B-lymphocytes, bone marrow
104
What is the activated form of B cells?
- plasma cells
| - synthesize and secrete antibodies
105
What is the immune component of cell-mediated immunity?
T-lymphocytes
106
T-lymphocytes mature in the...
thymus gland
107
Two types of T-lymphocytes in cell-mediated immunity:
- T8 lymphocytes (comes from CD8), which attack directly
- T4 lymphocytes (comes from CD4), which releases lymphokines that attract granulocytes to area and stimulates mitosis of immune cells
108
What is the function of memory cells?
remember specific antigens and quickly generate immune response when exposed to same antigen
109
Cell-mediated immunity gives...
long term protection against some viruses, bacteria, and cancer cells
110
Cell-mediated immunity involves the use of...
cytotoxic T cells, which attack infected body cells, cancer cells, foreign cells
111
Two important characteristics of antigens:
- reactivity: antibody binds specifically to the antigen that provoked it
- immunogenicity: ability to provoke an immune response by stimulating production of antibodies
112
Antigen can be...
- whole or part of cell
| - non-microbial
113
Example of non-microbial antigens:
- egg whites
- pollen
- incompatible blood cells
- transplanted tissues
114
What is an epitope?
small parts of the antigen where antibodies attach and provokes a response
115
Antibodies bind...
temporarily to target cell, which inactivates it and marks it for destruction
116
What are self antigens?
your own antigens, which allows the body to recognize which cells are yours
117
MHC proteins are important...
self-proteins that are a group of glycoproteins
118
MHC proteins are coded by...
genes of major histocompatibility complex (MHC), which are specific to each individual
119
T/F: identical twins have identical MHC
T
120
MHC proteins have a groove that can hold...
pieces of self or foreign antigen
121
T-lymphocytes can recognize only...
antigens that are presented on MHC proteins
122
What is important in tissue/organ transplant rejection?
self-antigens
123
Two types of antigen presentation:
- exogenous
| - endogenous
124
Steps of exogenous antigen presentation:
1. ingest antigen
2. digest antigen into peptide fragments
3. synthesize MHC-II molecules
4. package MHC-II molecules
5. bind peptide fragments to MHC-II molecules
6. insertion of antigen-MHC-II complexes into plasma membrane
125
Steps of endogenous antigen presentation:
1. digest antigen into peptide fragments
2. synthesis of MHC-I molecules
3. binding of peptide fragments to MHC-I molecules
4. packaging of antigen MHC-I complexes
5. insertion of antigen MHC-I complexes into plasma membrane
126
T cells are usually...
inactive
127
T cells are activated when it...
binds to foreign antigen
128
How do cytotoxic T cells kill target cells?
release perforins (makes a hole) and granzymes (enter via hole and destroy cell)
129
Antibody mediated immunity is carried out by...
B cells, which get activated in the spleen, lymphoid nodule, or lymph node in the presence of a microbe
130
Structure of antibodies match those of...
antigens, just like a lock and key
131
Antibodies are also known as...
immunoglobulins
132
Antibodies has 4 polypeptide chains:
- 2 heavy chains
- 2 light chains
- hinge region: flexible
- stem region
- in H and L region, there are variable and constant regions
133
Variable region in H and L area of antibodies is the...
antigen binding site
134
Constant region in H and L area of antibodies is the...
same in all antibodies of the same class
135
T cells mature in thymus under...
positive and negative selection pressures
136
Positive selection process for maturation of T cells:
selects T cells that can recognize self-MHC proteins
| - those who can't be recognizes are destroyed by apoptosis
137
Negative selection process for maturation of T cells:
prompts apoptosis of T cells that bind to self antigens displayed by self-MHC
- clonal deletion ensures self-tolerance
138
Antibody functions as...
- neutralizing antigen
- agglutinating antigen
- precipitating antigen
- activating complement
- opsonization
139
Adaptive immunity can be acquired via...
- active
| - passive
140
What happens during active adaptive immunity?
person's own immune system responds to microbe
141
What happens during passive adaptive immunity?
person receives antibodies from another person or animal
| - only temporary because no memory cells
142
Active and passive adaptive immunity can be either...
- natural
| - artificial
143
Natural actively acquired immunity develops when...
person is exposed to antigen by chance
| - ex: getting the flu
144
Artificial actively acquired immunity develops when...
person gets vaccines
145
Natural passively acquired immunity comes from...
mother to fetus
- placenta: IgG
- breast milk: IgA
146
Artificial passively acquired immunity develops when...
one receives serum containing antibodies
| - from person or animal that has been vaccinated
147
Process of self recognition:
1. self recognition
| 2. self tolerance
148
Loss of self tolerance during self recognition leads to...
autoimmune disorders
149
Two types of allergic reactions:
- immediate hypersensitivity
| - delayed hypersensitivity
150
What are naive immunocompetent B and T cells?
cells that are not yet exposed to antigens
| - called CD4 or CD8
151
Naive immunocompetent B and T cells are exported from...
primary lymphoid organs (bone marrow and thymus) to secondary lymphoid organs
152
Major types of APCs:
- dendritic cells
- macrophages
- B cells
153
Negative affects of immune response:
- autoimmune diseases
| - allergic reactions
154
Autoimmune diseases result when...
immune system loses ability to distinguish self from foreign
155
Autoimmunity is the production of...
autoantibodies and sensitized Tc cells that destroys body tissues
156
Rheumatoid arthritis:
autoimmune disease that destroys joints
157
Myasthenia gravis:
autoimmune disease that impairs nerve-muscle connections
158
Multiple sclerosis:
autoimmune disease that destroys white matter myelin
159
Graves' disease:
autoimmune disease that causes hyperthyroidism
160
Type 1 diabetes mellitus:
autoimmune disease that destroys pancreatic cells
161
Systemic lupus erythematosus (SLE):
autoimmune disease that affects multiple organs
162
Glomerulonephritis:
autoimmune disease that damages kidney
163
The two types of hypersensitivities are distinguished by...
- time course
| - whether antibodies or T cells are involved
164
When antibodies are involved in an allergic response, it causes...
immediate or subacute hypersensitivities
165
When T cells are involved in an allergic response, it causes...
delayed hypersensitivity
166
Steps of immediate hypersensitivities:
1. initial contact w/ allergen and sensitizes person
2. activated IgE against antigen binds to mast cells and basophils
3. later encounter with same allergen causes flood of histamine release from IgEs, which results in induced inflammatory response
167
Systemic response during immediate hypersensitivity leads to...
anaphylactic shock, which is usually seen with injected allergens
168
Subacute hypersensitivities are caused by...
IgM and IgG transferred via blood plasma or serum
169
Subacute hypersensitivities have a _____ onset and a ____ duration
short, long
170
Example of cytotoxic reactions:
mismatched blood transfusion
171
Example of immune complex hypersensitivity:
systemic lupus
172
Delayed hypersensitivity depends on...
helper T cells
173
TB test depends on what kind of reaction?
delayed hypersensitivity
174
Example of delayed hypersensitivity?
poison ivy reaction
