lecture 11 chapter 14 Flashcards
(209 cards)
1
Q
the interior of the human body is a ________ for microbes due to our immune system
A
hostile environment
2
Q
rapid, non-specific immunity, general protection plan that is present at birth and serves as our first line of defense for our entire life
A
innate immunity
3
Q
our specific immunity that develops throughout life and is tailor made to defend against the microbes or foreign material that we are exposed to
A
adaptive immunity
4
Q
what are first-line defenses?
A
barriers that block entry
5
Q
sensor systems in the body include:
A
sentinel cells and complement system
6
Q
what do sentinel cells use to identify unique microbial components?
A
pattern recognition receptors (PRRs)
7
Q
where is the complement system found?
A
in blood and tissue fluid
8
Q
what are the innate effector actions that can destroy invaders?
A
interferon (IFN), phagocytes, inflammatory response, fever, complement activation
9
Q
what is interferon secreted with?
A
viral infection
10
Q
what do phagocytes engulf?
A
microbes or cell debris by phagocytosis
11
Q
________ limits the infection and signals for help
A
inflammatory response
12
Q
_______ interferes with pathogen growth and enhances other immune responses
A
fever
13
Q
what are the “security walls” of the innate defenses?
A
first-line defenses (prevent microbial entry)
14
Q
what are the “security cameras” of the innate defenses?
A
sensor systems (detect damage and microbial invasion)
15
Q
what are the “security teams” of the innate defenses?
A
innate effector actions (eliminate invader)
16
Q
first line defenses
A
skin and mucous membranes
antimicrobial substances
17
Q
all exposed surfaces are lined with ______
A
epithelium
18
Q
tightly woven fibrous connective tissue
A
dermis
19
Q
the epidermis is made of:
A
many layers of epithelial cells
20
Q
is it easy for microbes to penetrate skin?
A
no
21
Q
the outermost layer of epithelial cells in the epidermis are _______
A
dead, filled with keratin
22
Q
keratin in the epidermis serves what purpose?
A
repels water, maintains dry environment
23
Q
what do the dead cells of the epidermis do?
A
continually flake off along with any attached microbes
24
Q
where are mucous membranes found?
A
digestive, respiratory, genitourinary tracts
25
what removes microbes in mucous membranes?
peristalsis of intestines, mucociliary escalator of respiratory tract
26
mucous membranes are constantly bathed in ______
secretions
27
salt accumulates on skin from _____
perspiration
28
______ degrades peptidoglycan
lysozyme
29
________ forms antimicrobials, consumes hydrogen peroxide to create more reactive forms of oxygen
peroxidases
30
what binds iron?
lactoferrin and transferrin
31
_______ form pores in microbial membranes
defensins
32
examples of antimicrobial substances that act as first-line defenses:
lysozyme, peroxidases, lactoferrin, transferrin, antimicrobial peptides (AMPs)
33
what can disruption of normal microbiota cause?
it can predispose a person to infections
34
_______ species degrade lipids, produce fatty acids
Cutibacterium
35
______ synthesizes colicins in intestinal tract
E. coli
36
______ in vagina produce low pH
Lactobacillus
37
normal microbiota helps in the production of ______
toxic compounds
38
normal microbiota are essential to the development of the _______
immune system
39
normal microbiota can cover binding sites and _______
consume available nutrients
40
another name for normal microbiota
flora
41
term for the development of cells in the immune system
hematopoiesis
42
blood cells originate from ______
hematopoietic stem cells
43
where are hematopoietic stem cells found?
in bone marrow
44
why are hematopoietic stem cells induced?
to develop by colony-stimulating factors (CSFs)
45
the cells of the immune system are always found in ______
normal blood
46
the number of immune system cells increase during _______
infections
47
where do some immune system cells reside?
in various tissues
48
what are the three general categories of immune system cells?
red blood cells (erythrocytes)
platelets (from megakaryocytes)
white blood cells (leukocytes)
49
what do red blood cells carry?
oxygen
50
platelets are involved in _______
clotting
51
white blood cells are important in _______
host defenses
52
examples of white blood cells
granulocytes, mononuclear phagocytes, lymphocytes
53
_______ contain cytoplasmic granules; named based on staining properties
54
_______ circulate in the blood, engulf and destroy bacteria
neutrophils
55
neutrophil granules contain ______
enzymes, antimicrobials (also called PMNs)
56
do neutrophils increase in number during infection?
yes
57
what are the primary microbial killers in the blood?
neutrophils
58
_______ involved in allergic reactions and inflammation
basophils
59
what do basophil granules contain?
histamine
60
what other cells are similar to basophils?
mast cells
61
where are mast cells found?
in tissues
62
_______ fight parasitic worms and are involved in allergic reactions
eosinophils
63
eosinophil granules contain _______
antimicrobials and histaminase
64
mononuclear phagocytes comprise _______
mononuclear phagocyte system (MPS)
65
mononuclear phagocytes includes _______ and cell types that develop as they leave the bloodstream
monocytes
66
_______ circulate in blood
monocytes
67
_______ differentiate from monocytes
macrophages
68
_______ found in nearly all tissues
sentinel cells
69
dendritic cells usually develop from _______
monocytes
70
_______ engulf material in tissues, bring it to cells of adaptive immune system for "inspection"
dendritic cells
71
sentinel cells function as _______
"scouts"
72
what cells are responsible for adaptive immunity?
lymphocytes
73
_______ are highly specific in recognition of antigen
B cells, T cells
74
where do B and T cells generally reside?
lymph nodes, lymphatic tissues
75
what lacks antigen recognition specificity?
innate lymphoid cells (ILCs)
76
innate lymphoid cells can promote _______
inflammatory response
77
natural killer (NK) cells are a type of innate lymphoid cell that destroy ______
certain types of cells
78
types of granulocytes
neutrophils
eosinophils
basophils
79
types of mononuclear phagocytes
monocytes
macrophages
dendritic cells
80
types of lymphocytes
B and T cells
innate lymphoid cells
81
what percentage of blood leukocytes are neutrophils?
55-65%
82
what percentage of blood leukocytes are eosinophils?
2-4%
83
what percentage of blood leukocytes are basophils?
0-1%
84
what percentage of blood leukocytes are monocytes?
3-8%
85
what percentage of blood leukocytes are lymphocytes?
25-35%
86
what do neutrophils perform?
phagocytosis
87
neutrophils release substances that ______
trap and destroy microbial invaders
88
_______ release chemicals that destroy eukaryotic parasites
eosinophils
89
where are eosinophils mainly found?
in tissues below the mucous membranes
90
mast cells are present in most tissues, where basophils are found in ______
blood
91
monocytes perform phagocytosis and can differentiate into either ______ or ______ when they migrate into tissues
macrophages, dendritic cells
92
important types of sentinel cell
macrophages, dendritic cells
93
do macrophages perform phagocytosis?
yes
94
B and T cells participate in _______
adaptive responses
95
_______ serve as "eyes" and "ears" of cell
surface receptors
96
surface receptors usually span _______
membrane, connect outside to inside
97
when surface receptors bind to a specific _______, a response is induced
ligand
98
_______ are "voices" of cell, transmit the signals
cytokines
99
_______ are produced by cells, diffuse to others, bind to appropriate receptors to induce changes
cytokines
100
what are the induced changes that cytokines can create when bound to appropriate receptors?
growth, differentiation, movement, cell death
101
where do cytokines act?
at low concentration; effects local, regional, systemic
102
_______ allow cells to adhere to other cells
adhesion molecules
103
example of adhesion molecule:
phagocytic cells can adhere to endothelial cells, allowing them to exit bloodstream
104
cytokines include:
chemokines
colony-stimulating factors (CSFs)
interferons (IFNs)
interleukins (ILs)
tumor necrosis factor (TNF)
105
what are chemokines?
chemotaxis of immune cells
106
what do colony-stimulating factors do?
multiplication and differentiation of leukocytes
107
what do interferons (IFNs) do?
control of viral infections, regulation of immune responses
108
what do interleukins do?
important in innate and adaptive immunity
109
what are interleukins produced by?
leukocytes
110
what do tuber necrosis factors assist in?
inflammation, apoptosis
111
groups of cytokines often act together or in sequence to _______
generate a response
112
example of cytokines group
pro-inflammatory cytokines (TNF, IL-1, IL-6)
113
what cytokines have sources from various cells?
chemokines, colony-stimulating factors, and interferons
114
source of interleukin 1 (IL-1)
macrophages, epithelial cells
115
source of interleukin 2 (IL-2)
T cells
116
source of interleukin 4 (IL-4)
T cells, mast cells
117
source of interleukin 6 (IL-6)
T lymphocytes, macrophages
118
what is the effect of IL-1?
T-cell activation; macrophage activation; induces fever
119
what is the effect of IL-2?
T-cell proliferation
120
what is the effect of IL-4?
promotes antibody response
121
what is the effect of IL-6?
T and B cell growth; inflammatory response; fever
122
what is the effect of tumor necrosis factor?
promotes inflammation
cytotoxic for some tumor cells
regulates certain immune functions
123
effect of interferons
regulates immune responses, antiviral
124
_______ "see" signs of microbial invasion; lead to cytokine secretion
pattern recognition receptors (PRRs)
125
what is detected by PRRs?
microbe-associated molecular patterns (MAMPs)
126
what do microbe-associated molecular patterns include?
cell wall components, flagellin subunits, microbial nucleic acid
127
are PAMPs exclusive to pathogens?
no
128
_______ indicate host cell damage
damage-associated molecular patterns (DAMPs)
129
where are pattern recognition receptors (PRRs) located?
cell surface
in endosomes and phagosomes
free in cytoplasm
130
_______ anchored in membranes of sentinel cells
toll-like receptors (TLRs)
131
what do surface TLRs monitor?
extracellular environment
132
what do TLRs in phagosomal or endosomal membranes of organelles characterize?
ingested material
133
toll-like receptors (TLRs) are specific for _______
distance MAMPs
134
dendritic cells have both _______ and _______
TLRs (toll-like receptors) and CLRs (c-type lectin receptors)
135
first step of the interferon response
PRRs detect viral RNA; cell produces interferon (IFN)
136
second step of the interferon response
interferon causes neighboring cells to express inactive antiviral proteins (iAVPs)
137
third step of the interferon response
iAVPs activated by viral dsRNA
138
what happens after iAVPs are activated by viral dsRNA in the interferon response?
mRNA is degraded, protein synthesis is stopped, and infected cells undergo apoptosis
139
_______ "complements" activities of adaptive immune system
the complement system
140
what is the complement system composed of?
proteins circulating in blood and tissue fluid
141
proteins of the complement system are named in _______
order discovered (C1 through C9)
142
proteins of the complement are able to split into _______
fragments (C3 splits into C3a and C3b)
143
what is the complement system activated by?
three different pathways that lead to formation of C3 convertase
144
what are the three protective functions/outcomes of Complement?
opsonization (augmenting phagocytosis)
promote inflammation
lysis of invading cells
145
what are the three pathways of complement activation?
alternative pathway
lectin pathway
classical pathway
146
_______ triggered when C3b binds to foreign cell surfaces
alternative pathway
147
is C3 stable or unstable?
unstable
148
_______: pattern recognition molecules bind to mannose of microbial cells, interact with complement system components
lectin pathway
149
_______: activated by antibodies bound to antigen, which interact with complement system
classical pathway
150
_______ is when C3b binds to bacterial cells and foreign particles, promotes engulfment by phagocytes that attach to opsonins
opsonization
151
_______ is when C5a attracts phagocytes to area; C3a and C5a increase permeability of blood vessels
inflammatory response
152
inflammatory response includes mast and other cells to release _______
histamines and other cytokines, resulting in diapedesis
153
_______: membrane attack complexes (MACs) assembling on the surface of gram-negative bacteria resulting in cell lysis and death
lysis of foreign cells
154
the membrane attack complexes during lysis of foreign cells are formed by which proteins?
C5b, C6, C7, C8, C9
155
_______ engulf and digest material invading microbes (pathogens)
phagocytes
156
what are phagocytes recruited by chemoattractants?
chemotaxis
157
examples of chemoattractants
products of microorganisms, phospholipids from injured host cells, chemokines, C5a
158
when phagocytes directly recognize and attach, what happens?
the receptors bind to mannose
159
when phagocytes indirectly recognize and attach, what happens?
the receptors bind to opsonins
160
what happens during engulfment?
psuedopods surround and form phagosome
161
_______ : phagosomes used with lysosomes containing degradative enzymes and antibacterial substances
phagosome maturation and phaoglysosome
162
what happens during the destruction and digestion of phagocytosis?
toxic ROS and nitric oxide produced
pH decreases
enzymes degrade
peptides damage membrane of invader
lactoferrin binds iron
163
_______: vesicle fuses with cytoplasmic membrane, expels remains
exocytosis
164
macrophages are important sentinel cells that alerts other _______
immune cells
165
how long do macrophages live?
weeks or months; regenerate lysosomes
166
macrophages are always present in _______; replaced by monocytes
tissues
167
macrophage funciton
phagocytize dead cells, debris, destroy invaders
168
_______ response to cytokine activation and TLR response
activated macrophages
169
_______ have greater killing power (acute phase of infection)
M1 macrophages
170
M2 macrophages help resolve inflammation and promote _______
tissue healing
171
if activated macrophages are insufficient, what occurs?
they can fuse, forming giant cells
172
what forms granulomas?
macrophages, giant cells, T cells
173
granulomas prevent escape, but they interfere with _______
normal tissue function
174
most active and potent phagocytic killer
neutrophils
175
_______play a critical role in early stages of inflammation
neutrophils
176
life span of neutrophils in tissues
1-2 days
177
are neutrophils more powerful than macrophages?
yes
178
what is the first white blood cell to be recruited to the site of damage?
neutrophils
179
when do neutrophils die?
once an assault on a microbe is made
180
neutrophils can release DNA to form _______
neutrophil extracellular traps (NETs)
181
what do neutrophil extracellular traps (NETs) do?
catch microbes, allowing enzymes and peptides from granules to destroy them
182
infection or tissue damage results in _______
inflammation
183
what is the purpose of inflammation?
to contain site of damage, localize response, eliminate invader, and restore tissue function
184
what does inflammation often result in?
swelling, redness, heat, pain, sometimes loss of function
185
what triggers the inflammatory response?
pattern recognition receptors (PRRs)
186
inducers of the inflammatory response include _______
microbes, tissue damage
187
MAMPs cause release of _______ that induces liver to produce acute phase proteins that activate complement
tumor necrosis factor (TNF)
188
blood vessel damages starts _______ ; lead to coagulation and increased vessel permeability
two enzymatic cascades
189
sequence of events for the inflammatory process:
dilation of small blood vessels, migration of leukocytes form bloodstream to tissues, clotting factors wall off site of infection, dead neutrophils/tissue debris accumulate as pus
190
dilation of small blood vessels results in:
greater blood flow (heat, redness); slower flow rate, leakage of fluids
191
when blood vessels dilate and fluids leak, what do these fluids contain?
transferrin, complement, antibodies
192
what is margination?
endothelial cells "grab" phagocytes, slow them down
193
what is diapedesis?
phagocytes squeeze between cells of vessel
194
clotting factos walling off this site of infection is crucial because:
it prevents bleeding and stops spread of microbes
195
_______ is short term, mainly neutrophils; macrophages clean up damage by ingesting dead cells and debris
acute inflammation
196
if acute inflammation fails, what results?
chronic inflammation
197
what happens during chronic inflammation?
macrophages, giant cells accumulate, and granulomas form
198
why can inflammation be compared to a fire sprinkler system?
because it prevents spread, but still damages the building
199
during inflammation, _______ form phagocytic cells are released, damaging tissues
enzymes and toxic compounds
200
damage from inflammation is usually minimal, but in delicate systems (membranes surrounding brain, spinal cord), it can be _______
severe, even life-threatening
201
traumatic cell death due to damage is called
necrosis
202
programmed cell death; does not trigger inflammatory response
apoptosis
203
PRRs in a macrophage trigger an inflammatory response that sacrifices infected cells
pyroptosis
204
_______ is indicator of infection, especially bacterial
fever
205
temperature-regulation center in brain normally hold at _______ but raises during infection in response to pyrogens
37 degress Celsius
206
pyrogens may be made by _______
the body or by microbes
207
oral temperature above _______ is regarded as fever
37.8 degrees Celsius
208
growth rates of bacteria optimized for 37 degrees celsius typically drop sharply above optimum, what does this allow more time for?
defenses
209
moderate temperature rise increase rates of _______
enzymes
