Chapter 22 Flashcards
(112 cards)
1
Q
what is a pathogen?
A
a disease-causing organism
2
Q
what is immunity?
A
the ability to resist infection and disease
3
Q
what is the compositional difference between lymph and plasma?
A
lymph contains a much lower concentration of suspended proteins
4
Q
what’s the difference between primary and secondary lymph organs?
A
primary: where T & B cells mature
secondary: where T & B cells encounter their antigen
5
Q
name two primary lymph tissues/organs
A
red bone marrow & thymus
6
Q
name four secondary lymphoid tissues/organs
A
tonsils
MALT (mucosa associated lymphatic tissue)
lymph nodes
spleen
7
Q
what is the function of lymphatic vessels?
A
carry lymph to veins near the heart and return leaked fluids back to blood
8
Q
regarding pathogens, what is the importance of valves in immune function?
A
prevent the backflow of lymph
9
Q
what feature do lymphatic vessels share with veins that allows lymph to flow in only one direction?
A
the presence of valves
10
Q
define lymphedema
A
obstruction of lymphatic vessels
11
Q
list two types of phagocytes associated with immune function
A
macrophages & microphages
12
Q
list three classes of lymphocytes that circulate in blood
A
B cells, T cells, NK cells
13
Q
what are tonsils?
A
large lymphoid nodyles in the walls of the pharynx
14
Q
which tonsils are usually inflamed when a patient experiences tonsillitis?
A
palatine tonsils, located at the back of the oral cavity
15
Q
what does the acronym MALT stand for, and where is it located in the body?
A
mucosa-associated lymphoid tissue
in lining of digestive, respiratory, urinary, and reproductive systems
16
Q
list three examples of MALT. where are peyer’s patches located?
A
appendix, tonsils, peyer’s patches (small intestine)
17
Q
what is the functional difference between afferent and efferent lymphatic vessels?
A
lymph arrives to node through afferent vessels, and exits through efferent vessels
18
Q
which cells located in the subscapular space of a lymph node initiate the immune response?
A
dendritic cells
19
Q
what is the function of lymph nodes?
A
filter lymph of harmful pathogens and foreign substances
20
Q
how are lymph nodes like early warning systems?
A
antigens in lymph stimulate macrophages and lymohocytes in nearby nodes
21
Q
what are thymosins and why are they important?
A
promote development and maturation of T cells
22
Q
list three functions of the spleen
A
- remove abnormal blood cells by phagocytosis
- store iron recycled from RBCs
- initiate immune responses by B and T cells in response to antigens
23
Q
state the difference between red pulp and white pulp
A
red pulp: contains large quantities of RBC and macrophages
white pulp: contains a lot of WBCs and lymphoid follicles
24
Q
why is innate immunity considered nonspecific?
A
it does not distinguish one potential threat from another
25
what lymphocytes are involved in innate immunity? in adaptive immunity?
innate: NK cells
adaptive: T cells & B cells
26
define lymphocytopoiesis
lymphocyte formation in the red bone marrow
27
where do B cells develop and mature? T cells? NK cells?
B cells: bloodstream to peripheral tissues
T cells: thymus
NK cells: bloodstream to peripheral tissues
28
are first line defenses innate or adaptive?
innate
29
true or false? adaptive immune defenses deny pathogens access to the body or destroy them without distinguishing among specific types.
false, innate defenses do this
30
describe the function of the following innate defense: physical barriers
keep hazardous organisms and materials outside the body
31
describe the function of the following innate defense: phagocytes
engulf pathogens and cell debris
32
describe the function of the following innate defense: immune surveillance
destruction of abnormal cells by NK cells in peripheral tissues
33
describe the function of the following innate defense: interferons
chemical messengers that coordinate defenses against viral infections
34
describe the function of the following innate defense: complement
system of circulating proteins that assist antibodies in destruction of pathogens, cell lysing, phagocytosis, and inflammation
35
describe the function of the following innate defense: inflammation
localized, tissue-level response that tends to limit the spread of infection or injury
36
describe the function of the following innate defense: fever
elevation of body temperature that speeds up tissue metabolism and activity of defenses
37
name two physical barriers
skin (epidermis and dermis) & mucous membrane
38
what two protective components are secreted on epidermal surfaces to reduce pathogen numbers? how do they work?
sebaceous and sweat glands: wash away microorganisms and chemicals (may contain lysozymes)
39
name two kinds of microphages
neutrophils, eosinophils
40
give two examples of fixed macrophages
microglia (CNS)
stellate (liver)
41
what occurs during emigration?
fixed and free microphages move through capillary walls by squeezing between adjacent endothelial cells
42
define chemotaxis
attraction of phagocytic cells to the source of abnormal chemicals in tissue fluids
43
what molecules are made and released after NK cell activation? what is their function?
perforins: go from NK cell to target and open pores, restricting abnormal cell from maintaining its internal environment and desintegrating
44
what are interferons? what does a rise in levels of interferons suggest?
proteins released by activated lymphocytes and macrophages that trigger production of antiviral proteins
rise in levels indicates the body is responding to a viral infection
45
what proteins interact with one another in a chain reaction known as cascades? what do they do?
complement proteins
enhance the actions of antibodies and phagocytes
46
how is the classical complement pathway activated?
binding of protein C1 to two nearby antibodies ALREADY attached to specific antigen
47
how is the lectin complement pathway activated?
protein mannose-binding lectin (MBL) binds to carbs on pathogen surfaces
48
how is the alternative complement pathway activated?
several complement proteins (properdin, factor B, and factor D) interact in the plasma, triggered by exposure to foreign materials
49
complement activation using any of the three pathways produces three results. what are they?
1. killing of pathogen (cell lysis)
2. enhanced phagocytosis (opsonization)
3. inflammation
50
what is a MAC complex and what is its function?
creation of pores in the membrane of target cells
51
what is opsonization?
enhancement of phagocytosis
52
what specific chemical is released by mast cells and basophils that increases the degree of local inflammation?
histamine and heparin
53
what are the four cardinal signs and symptoms of inflammation?
redness, swelling, heat, pain
54
once neutrophils are activated, they undergo a respiratory burst. what two reactive chemicals do activated neutrophils produce? what is the outcome of their release?
nitric oxide & hydrogen peroxide
destruction of pathogens and attraction of other neutrophils/macrophages to the area
55
what is necrosis?
tissue destruction that occurs after cells have been injured
56
what is an abscess?
accumulation of pus, the mixture of debris, fluid, and dead cells
57
what are pyrogens? how do they work?
fever inducing agents that reset thermostat in hypothalamus and raise body temp
58
list four main types of T cells and their functions
cytotoxic T cells - direct cellular attack
helper T cells - stimulate responses of T and B cells to produce antibodies
regulatory T cells - subset of T cells that moderate immune response
memory T cells - respond to previously encountered antigens by cloning to ward off invader
59
what are stimulated B cells called? what do they secrete?
plasma cells; antibodies
60
define antigen
substance capable of inducing an immune response
61
what organic molecules comprise most antigens? what are three additional organic molecules that can act as antigens?
usually proteins; can be lipids, polysaccharides, and nucleic acids
62
true or false: clones of the same activated lymphocyte are sensitive to the same specific antigen
true
63
describe four types of adaptive immunity and explain how the immunity is acquired
naturally acquired active
artificially acquired active
naturally acquired passive
artificially acquired passive
64
what type of adaptive immunity occurs by contracting SARS-CoV-2, the causative agent of COVID-19 from your brother?
naturally acquired active
65
what form of adaptive immunity occurs when a person is vaccinated against COVID-19?
artificially acquired active
66
patients who have COVID-19 can be treated with lab produced antibodies against the SARS-CoV-2 spike protein. what type of adaptive immunity is this?
artificially acquired passive
67
women who produced antibodies against SARS-CoV-2 while pregnant or from previous exposure can transfer a certain isotype of antibody across the placenta. what type of immunity is this?
naturally acquired passive
68
adaptive immunity is specific; what does this mean?
defense is activated by a specific antigen, and target is that same antigen and no others
69
what is immune tolerance?
lack of immune response to antigens that don't stimulate a response
70
define apoptosis
cell programed death
71
what are APCs and what are their function?
antigen-presenting cells; activate T cell defenses against foreign cells
72
what are MHCs? what is another name they are known by? what is their importance?
major histocompatibility complex, also known as human leukocyte antigens
recognizes antigens and plays role in coordination and activation of immune response
73
what must be recognized for antigen presentation to occur?
occurs when antigen-MHC capable of activating T cells appears in plasma
74
what blood group is considered the universal donor? universal recipient? why?
donor: O; all blood types can receive O-
recipient: AB; AB+ can receive all blood types
75
what do tissue typing tests determine?
assesses human leukocyte antigens for organ or tissue transplantation
76
what do cross matching tests determine?
incombatibility between donor and recipient blood
77
which cells have MHC class 1 proteins?
nucleated cells (contain nucleus)
78
what triggers antigen presentation by class II MHC proteins?
when a pathogen is engulfed and the antigen (fragment of pathogen)
79
which cells have MHC class II proteins?
free/fixed macrophages
stellate macrophages of liver
microglia of CNS
80
list three examples of phagocytic antigen-presenting cells
free/fixed macrophages
stellate macrophages of liver
microglia of CNS
81
name one example of non-phagocytic antigen-presenting cells. where are they found?
B cell
82
which cells have CD8 markers? antigen bound to which MHC class do they detect?
cytotoxic T cells & regulatory T cells
class I MHC proteins
83
which cells have CD4 markers? antigen bound to which MHC class do they detect?
helper T cells
class II MHC proteins
84
what is costimulation and what is its function?
the binding of a T cell to a stimulating cell to proceed from recognition to activation
85
what is the function of regulatory T cells?
moderate responses of other T and B cells by secreting suppression factors (they act after the immune response)
86
what molecules are produced by T helper cells that function to coordinate specific and nonspecific defenses and stimulate cell-mediated and antibody-mediated immunities?
produce memory T cells and speed maturation of cytotoxic T cells
87
a sensitized B cell does not undergo activation unless it receives the "ok" from which type of cell?
helper T cell
88
what are two pairs of polypeptide chains of a Y-shaped antibody molecule called?
heavy chains and light chains
89
the specificity of an antibody molecule depends on the amino acid sequence of which region of the antibody?
the variable segments of the light and heavy chains
90
antibodies bind to specific portions of an antigen's exposed surface. what are these antigenic determinant sites called?
epitopes
91
what is a hapten?
partial antigens that attach to carrier molecules, forming combinations that can function as complete antigens
92
which antibody type is most prevalent in the body and is the only antibody class that can cross the placenta?
IgG (immunoglobulin G)
93
which antibody is most important in allergic responses?
IgE (immunoglobulin E)
94
which antibody is the first to be secreted the first time an antigen is encountered?
IgM
95
which antibody has five antibody molecules connected to form a starburst shape?
IgM
96
blood typing uses agglutination reactions using anti-A and anti-B. what class of antibody are anti-A and anti-B?
IgM
97
which antibody is found in body secretion such as tears and saliva and can have a structure of two connected antibodies which a secretory molecule?
IgA
98
what is a primary and secondary response? which one is more extensive and prolonged?
primary response - initial response to antigen (LONGER, antigen must activate appropriate B cells)
secondary response - triggered when antigen appears again
99
during the primary response, which antibody peaks sooner? during secondary?
primary - IgM (1.3 weeks)
secondary - IgG (2+ weeks)
100
why does the secondary response produce IgG quicker than in the primary response?
memory B cells are activated, which respond more quickly and produce antibodies in larger quantities upon re-exposure
101
during times of chronic stress, what type of hormones produced by the adrenal cortex can inhibit the immune system?
ACTH --> glucocorticoids
have anti-inflammatory properties that suppress immune response
102
what are allergens?
hypersensitivities: excessive immune responses to antigens
103
which category of hypersensitivity (1-4) are immediate hypersensitivities, occuring rapidly and eliciting especially severe responses to an antigen?
type 1
104
during type 1 hypersensitivities, the first encounter with an antigen sensitizes the immune system. what class of antibodies are produced and what cells do they bind to?
IgE; bind to basophils and mast cells
105
what occurs when there is a second exposure to an allergen? what molecule is released by mast cells and basophils that results in a sudden, massive inflammation of the affected tissues in the area of exposure?
106
what is anaphylaxis?
when a circulating allergen affects mast cells throughout the body
107
a severe immune response caused by circulating antigens that affect mast cells throughout the body can result in extensive peripheral vasodilation, producing a drop in blood pressure that can lead to circulatory collapse. what is this response called?
anaphylactic shock
108
what are drugs such as benadryl used for? what does it block?
antihistamines; block the action of histamine, preventing symptoms of immediate hypersensitivity
109
what medical treatment is used to combat anaphylactic shock?
antihistamines, corticosteroids, epinephrine
110
what causes an autoimmune disorder?
activated B cells make antibodies against other body cells and tissues
111
what cells are specifically infected by HIV?
helper T cells
112
worldwide, what is the most common way that individuals contract HIV? what is the second most common way?
1. unprotected sex
2. sharing contaminated needles or syringes
