Chapter 21 (Lecture) Flashcards
1
Q
ability of the body to resist many agents (both living and nonliving) that can cause disease; resistance to disease
A
immunity
2
Q
- first line of defense: surface barriers such as intact skin and mucosae
- second line of defense (internal): antimicrobial proteins, phagocytes, fever, NK cells, and other cells; hallmark is inflammation
- NO MEMORY
A
innate (nonspecific) immune system
3
Q
- takes considerably longer to mount
- humoral immunity
- cellular immunity
- MEMORY; each response is unique, and second exposure is quicker
A
adaptive (specific) defense system
4
Q
- a functional system rather than an organ system in an anatomical sense
- structures are a diverse array of molecules plus trilions of immune cells (especially lymphocytes) that inhabit lymphoid tissues and circulate in bodily fluids
A
immune system
5
Q
harmful or disease-causing microorganisms
A
pathogens
6
Q
benefits of keratin
A
resistant to most weak acids, alkalis and bacterial enzymes
7
Q
protective chemicals of the innate immune system
A
- acid (acid mantle)
- enzymes
- mucin
- defensins
- lipids, sebum and dermicidin
8
Q
protective mechanism: normally acidic pH inhibits bacterial growth; cleanses the lower urinary tract as it flushes from the body
A
urine
9
Q
protective mechanism: continuously lubricate and cleans eyes (tears) and oral cavity (saliva): contain lysozyme, an enzyme that destroys microorganism
A
tears, saliva
10
Q
protective mechanism: inhibits growth of most bacterai and fungi in female reproductive tract
A
acid mantle of the vagina
11
Q
protective mechanism: contains concentrated hydrochloric acid and protein-digesting enzymes that destroy pathogens in the stomach
A
gastric juice
12
Q
protective mechanism: propel debris-laden mucus away from nasal cavity and lower respiratory passages
A
cilia
13
Q
protective mechanism: filter and trap microorganisms in respiratory and digestive tracts
A
nasal hairs
14
Q
protective mechanism: traps microorgansim in respiratory and digestive tracts
A
mucus
15
Q
protective mechanism: skin secretions (sweat and sebum) make epidermal surface acidic, which inhibits bacterial growth; also contain various bactericidal chemcials
A
acid mantle of skin
16
Q
vesicle formed as a result of phagocytosis
A
phagosome
17
Q
- phagocytes
- about 126B/day produced
- usually the first WBC to make it to an infection
- 1 time use
A
neutrophils
18
Q
made up of dead neutrophils, microbes, pathogens
A
pus
19
Q
- monocytes in blood, this in tissue
- leave blood and increase in numbers at site of infection
- cleanup crew
- dendritic cells, microglia, alveolar, hepatic
A
macrophages
20
Q
- mobile
- release factors that attract more WBCs
A
basophils
21
Q
- immobile
- are found near sites of possible pathogen influx
- release chemotaxic factors
- can also phagocytize bacteria
A
mast cells
22
Q
factors that attract more WBCs
A
chemotaxic factors
23
Q
act as moderators of inflammatory response and kill parasites by releasing enzymes all over them
A
eosinophils
24
Q
- B cells and T cells
- Natural Killer Cells (NKC)
A
lymphocytes
25
recognize tumor and cancerous cells in general
NKC (natural killer cells)
26
* prevents the spread of damaging agents to nearby tissues
* disposes of cell debris and pathogens
* sets the stage for the repair process
inflammatory process
27
cardinal signs of inflammation
* redness
* heat
* swelling
* pain
28
* happens after first exposure, involves the creation of killer T cells and memory cells
* usually takes about 3-7 days, and you will feel sick during this time
primary response
29
occurs upon a repeated exposure to the same antigen or a similar formand the memory clels recognize it and the response is faster and of greater magnitude
secondary response
30
long-lived and require less activation to respond than do other APCs
memory T cells
31
* production is regulated by helper T cells and antigen presenting cells
* once activated, proliferate and produce Killer Ts and memory T cells
cytotoxic T cells
32
effects of cytotoxic T cells
* cause cells to lyse (contact killing) by releasing perforins
* cause the release of cytokines that attract cells such as macrophages and WBCs (inflammatory response)
33
caused by the release of histamines, prostaglandins, etc. from the injured tissues
vasodilation
34
allows protein rich fluid to seep into the injured region from the blood vessels
vascular permeability
35
which factors cause edema in the injured area
vasodilation and vascular permeability
36
steps of phagocyte mobilization
1. leukocytosis
2. margination
3. diapedesis
4. chemotaxis
37
follows chemical signals to injured site
chemotaxis
38
# true or false:
inflammatory response can be localized or systemic in nature
true
39
functions of antimicrobial proteins
* preventing entrance to cell
* vasodilation
* increased permeability
* attracting WBCs
* increasing phagocytosis
40
* protects body against viral attack
* mobilize NK cells
* can be released by lymphocytes to cause widespread immune mobilization
interferon
41
virus infected cells produce interferon which
stimulates neighboring cells to produce antiviral proteins
42
A group of bloodborne proteins, which, when activated, enhance the inflammatory and immune responses and may lead to cell lysis.
complement system
43
classical complement pathway is stimulated by
antibodies
44
alternate complement pathway is stimulated by
factors C3 which break down into different compounds
45
complement works in which response
both the innate and adaptive resopnses
46
a systemic response that involves the release of pyrogens
fever
47
events of phagocytosis
1. phagocyte adheres to pathogens or debris (using receptors)
2. phagocyte forms pseudopods that eventually engulf the particles, forming a phagosome
3. lysosome fuses with the phagocytic vesicle, forming a phagolysosome
4. toxic compounds and lysosomal enzymes destroy pathogens
5. sometimes exocytosis of the vesicle removes indigestible and residual material
48
* wander throughout the tissue spaces in search of cellular debris or "foreign invaders"
free macrophages
49
such as stellate macrophages in the liver, are permenant residents of particular organs
fixed macrophages
50
when neutrophils enter blood from the bone marrow
leukocytosis
51
neutrophils cling to the capillary wall
margination
52
neutrophils flatten and squeeze out of capillaries
diapedesis
53
steps of interferon release/production
1. virus enters cell
2. interferon genes switch on
3. cell produces interferon molecules
4. interferon binding stimulates cell to turn on genes for antiviral proteins
54
* antigen-antibody complex
* C1, C4, C2 complex
classical pathway of complement system
55
coats pathogen surfaces, which enhances phagocytosis
opsonization
56
steps to contact killing
1. cytotoxic t cell binds tightly to the target cell when it identifies foreign antigen on MHC I proteins
2. Tc releases perforin and granzyme molecules from the granules by exocytosis
3. perforin molecules insert into the target cell membrane, polymerize, and form transmembrane pores similar to thsoe produced by complement activation
4. granzymes enter the target cell via the pores. once inside, the proteases degreade cellular contents, stimulating apoptosis
5. Tc detaches and searches for another prey
57
steps TH cells use to help in humoral immunity
1. TH cells binds with the self-nonself complexes of a B cell that has encountered its antigen and is displaying it on MHC II on its surface
2. TH cell releases interleukins as a co-stimulatory signals to complete B cell activation
58
steps of TH cells in cell-mediated immunity
1. previously activated TH cell binds dendritic cell
2. TH cell stimulates dendritic cell to express co-stimulatory molecules needed to activate CD8 cell
3. dendritic cell can now activate CD8 cel with the help of IL2 secreted by TH cell
59
steps to the activation of T cells
* dendritic cells engulfs an exogenous antigen, processes it,, and displays its fragments on class II MHC protein
* immunocompetent CD4 cell recognizes antigen-MHC complex. both T-Cell Receptor and CD4 protein bind to antigen-MHC complex
* CD4 cells are activated, proliferate, and become memory and effector cells
60
* fixes complement, often first produced
* powerful agglutinogen
IgM
61
secreted into tears and colostrum, protects body surfaces
IgA
62
binding site on B-cells
IgD
63
activates complement, found in plasma
IgG
64
binds to mast cells and basophils, stimulates inflammation
IgE
65
types of active immunity
* naturally acquired
* artificially acquired
66
types of passive immunity
* naturally acquired
* artificially acquired
67
types of humoral immunity
* active
* passive
68
immunity that comes from infection; contact w/ pathogen
naturally acquired active immunity
69
acquired from vaccines; dead or attenuated pathogens
artificially acquired active immunity
70
comes from antibiodies passed from mother to fetus via placenta; or to infant in her milk
naturally acquired passive immunity
71
acquired from injection of immune serum (gamma globulin)
artificially acquired passive immunity
72
why can B-cells act as APCs
their receptors are antibodies
73
* dendritic cells, macrophages, activated B lymphocytes
* engulf antigens and produce fragments on their surface attached to MHC complexes
antigen presenting cells
74
* spontaneous activation
* stabilizing factors B, D, and P
* no inhibitors on pathogen surface
alternative complement pathway
75
* secreted by macrophages and neutrophils exposed to foreign substances
* stimulates the hypothalamus to make prostaglandin E
pyrogens (IL1)
76
what is the role of prostaglandin E
raises the set point for the body's internal temperature
77
how do NSAIDs reduce fever
by inhibiting PGE synthesis
78
benefits of fever/pyrexia
* promotes interferon activity
* elevate metabolic rate to promote healing
* inhibit reproduction of pathogens
79
anything above what internal temperature will cause delirium and higher temperature cause irreversible damage
105
80
* found in macrophages, B cells, and monocytes
* processed antigens will cause costimulation to occur
MHC II
81
found in nucleated cells, causes red flag to be raised if they display a foreign antigen
MHC I
82
* displayed by all body cells, usually by MHC I complexes
self antigens
83
* region on the surface of an antigen that is immunogenic
* simple antigens may have only one or two of these
* more complex ones may have hundreds that bind and activate different types of antibody
antigenic determinants/epitopes
84
usually polymers that are not deemed reactive by the body
implants
85
* both immunogenic and reactive
* viruses, bacteria, fungi, etc
complete antigens
86
haptens, pet dander, poison ivy, cosmetics, perfumes
haptens
87
reactive, but not immunogenic so they only cause a reaction if they bind to other proteins in our body
haptens
88
* any molecule that triggers an immune response
* usually have a fairly high molecular weight
* complex molecules that are unique to individuals (proteins, polysaccharides, glycoproteins, glycolipids)
* body usually only attacks "non-self"
antigens
## Footnote
Ag, antigen generating
89
* antigen-specific
* systemic
* memory
* two major components: humoral and cell-mediated immunity
adaptive response
90
which lymphocytes are responsible for humoral immunity
b cells
91
which lymphocytes are responsible for cell-mediated immunity
T cells
92
produced from lymphoblast precursors in red bone marrow
lymphocytes
93
reach maturity in the bone marrow before being released
B cells
94
immature T-cells migrate where before maturation
thymus
95
* created in red bone marrow, but soon leave
* mature in thymus gland--undergo positive and negative selection
* after selection they colonize lymphatic tissue and organs everywhere in the body
T-cells
96
if they do not react to foreign antigens or if they DO react to self antigens they are culled from the population
negative selection
97
if they react to foreign antigen, but not to self antigen
positive selection
98
* mature in bone marrow
* undergo a similar type of seletion as T cells
* once they are mature they colonize many of the same tissues as T cells
B cells
99
overall goal of any cell that acts as an APC
interact the antigen and then stimulate the two arms of the specific immune response
100
# true or false:
T cells can detect antigens on their own
false
101
the process wherein the MHC II complex of an APC binds with a helper T cell and this stimulaates the release of cytokines between the two cells which causes the helper T cells to either:
* proliferate and produce more helper T cells
* stimulate B or T cells
costimulation
102
* most effective agianst intracellular microorganisms such as viruses, fungi, bacteria, and parasites
* activation regulated by antigen-presenting cells and helper T-cells
T-cells
103
types of T cells
* cytotoxic
* helper
* memory
104
killer, CD8, or T8 t-cells
cytotoxic T cells
105
CD4 T-cells, activate CD8 cells and also stimulate antibody mechanisms
helper T cells
106
come from cytotoxic cells and remember the pathogens
memory T cells
107
* have receptors on their surface for an antigen
* when they are challenged by an antigen, activates specific receptors and begins stimulating them to divide
naive B cells
108
rapidly creates plasma cells and memory cells
clonal selection of B cells
109
secrete antibodies at rates up to 2000/s for 4-7 days
plasma cells
110
long lived and retain the imprint of the antigen so they can respond almost immediately to future attacks
memory cells
111
effects of antibodies
* neutralization
* agglutination
* precipitation
* complement
112
antibody can bind directly to the antigenic determinant and interfere with or deactivate the antigen
neutralization
113
antibody can combine with the antigenic determinants on two antigens rendering them ineffective adn making them more susceptible to phagocytosis
agglutination
114
small water soluble antigens are settled out of solution and are then engulfed
precipitation
115
antibodies can activate the complement cascade, and release factors which induce the inflammatory response and cell lysis
complement
116
variable regions of the antibody
heavy and light chains
117
regions of the antibody that bind and activate the complement
constant regions
118
what are B cells most effective against
extracellular bacteria, parasites, and viruses
119
B cells respond to invasion by producing antibodies that are specialized globulins known as
immunoglobulins (Ig)
120
antibodies are injected from another source
passive immunity
| w
121
individuals will produce their own antibodies
active immunity
122
individual is exposed and develops antibodies and memory cells
active natural immunity
123
* vaccination; antigen is introduced in altered form
* memory cells formed
active artificial immunity
124
* passed from mother to newborn through placenta/milk (IgA)
* effects wear off in a few months as the child's own immune develops
passive natural immunity
125
* antibodies taken from another source are given via a vaccination
* quick fix as body will produce no antibodies naturally
passive artificial immunity
126
steps to fever onset
* hypothalamic thermmostat is reset to higher set point
* onset: body temp rises
* stadium: body temp oscillates around new set point
* infection ends, set point returns to normal
* defervescence: body temp returns to normal
127
steps to lymphocyte maturation
1. lymphocytes destined to become T cells migrate (in blood) to the thymus and develop immunocompetence there. b cells develop immunocompetence in red bone marrow
2. immunocompetent but still naive lymphocytes leave the thymus and bone marrow. "seed" the lymph nodes, spleen, and other lymphoid tissues where they encounter their antigen
3. antigen-activated immunocompetent lymphocytes (effector cells and memory cells) circulate continuously in the bloodstream and lymph and throughout the lymphoid organs of the body
128
steps to endogenous protein processing and display
1. endogenous antigen is degraded by protease
2. endogenous antigen peptides enter ER via a transport protein
3. endogenous antigen peptide is loaded onto class I MHC protein
4. loaded MHC protein migrates in vesicle to the plasma membrane, whete it displays the antigenic peptid
129
steps to exogenous protein processing and display
1a. class II MHC synthesized in ER
1b. extracellular antigen is phagocytized
2a. class II MHC is exported from ER in vesicle
2b. phagolysosome degrades antigen
3. vesicle fuses with phagolysosome, invariant chain is removed, and antigen is loaded
4. vesicle with loaded MHC migrates to the plasma membrane
130
MHC II display can cause
costimulation
131
fluid containing clotting factors and antibodies
exudate
132
* a lipid-based chemical messenger synthesized by most tissue cells; acts locally as a paracrine
* produced from arachidonic acid
prostaglandins
133
vasodilation of local arterioles cause
local hyperemia
134
increased blood flow due to vasodilation of blood vessels entering the injured area
hyperemia
135
which minerals needed for bacterial reproduction do both the liver and spleen sequester during a fever
iron and zinc
136
when collagen fibers are laid down to a wall of a sac of pus, what structure is formed
abscess
137
mechanism of complement proteins
foorming pores in the membranes of target cells
138
function of neutrophils
phagocytes, will migrate to the site of an infection within a few hours
139
fever inducing molecules are secreted by leukocytes and macrophages
pyrogens
140
which defense cells are common antigen presenting cells (APCs)
macrophages
141
caused by excess tissue fluid in the injured area; helps to dilute harmful substances and brings in excess oxygen
edema
142
nonspecific defense cels specialize in attack cancer cells and virus-infected cells
natural killer cells
143
enzyme in saliva and lacrimal fluids that destroys bacteria
lysozyme
144
a process of coating a pathogen to enhance phagocytosis
opsonization
145
fluid that seeps from the capillary contains clotting factors and antibodies during inflammation
exudate
146
when a localized area exhibits increased capillary filtration, hyperemia, and swelling, it is indication that
inflammation is occurring
147
an increase in the number of white blood cells that are in circulation
leukocytosis
148
process in which neutrophils squeeze through walls of capillaries into the tissues
diapedesis
149
a person may harbor pathogens walled off in ... for years without displaying any symptoms
granulomas
150
first line of defense against pathogens
skin and mucous membranes
151
which of the following is the most specific internal defense against disease
a. inflammation
b. NK cells
c. T cells
d. phagocytes
T cells
## Footnote
T cells are a part of the adaptive (specific) defenses against disease. They are involved in cell-mediated immunity as they defend the body against specific pathogens.
152
brings more leukocytes to the site of infection
inflammation
152
# true or false:
virus-infected cells secrete interferons to "warn" other cells of the presence of virus and these other cells and inhibit viral replication
true
153
role of interferons in defense against disease
protects cells that have not yet been infected by viruses
154
* requires that circulating antibodies are bound to antigens
* an example of overlap between innate and adaptive immune function
* will result in enhanced inflammation, opsonization as well as formation of MAC proteins
classical activation of complement system
155
* sets the stage for repair processes
* prevents the spread of injurious agents to nearby tissue
* disposes of cellular debris and pathologies
functions of the inflammatory process
156
redness and heat of an inflamed area are due to local hyperemia caused by
vasodilation
157
unless they are attached to protein carriers, haptens have ... but not ...
reactivity but not immunogenicity
158
how do vaccines work
by priming the adaptive immunity with a relatively harmless primary exposure
## Footnote
artificially acquired active immunity
159
results when naive lymphocytes are activated
primary response
160
result of activating memory cells
secondary response
161
A class I MHC protein presents an antigen. What type of cell is likely presenting and to what type of cell would it be presented?
Any nucleated cell would present antigens to a CD8 cell.
162
Which lymphocytes act as the bridge between the cellular and humoral responses?
helper T cells
163
What types of antigen do mature T cells normally not recognize?
self antigens
