Exam 1: Cells and Organs of the IS Flashcards
1
Q
What are some first lines of defense against infection?
A
skin, mucous membranes, chemicals
2
Q
What are some second lines of defense against infection?
A
Phagocytosis, complement, interferon, inflammation, fever
3
Q
What are some third lines of defense against infection?
A
Lymphocytes, antibodies
4
Q
which line of defence (1st, 2nd, 3rd) is specific?
A
3rd
5
Q
subgroup of WBCs characterized by the presence of cytoplasmic granules
A
Granulocytes
6
Q
Where are granulocytes produced?
A
Bone marrow
7
Q
What are the 3 granulocytes?
A
Basophils, eosinophils, neutrophils
8
Q
What is another name for granulocytes?
A
Polymorphonuclear leukocytes
9
Q
What is the importance of basophils?
A
defense against parasites and inflammatory response
10
Q
How do basophils destroy pathogens?
A
toxic granules destroy pathogen during phagocytosis
11
Q
What are 3 adhesion molecules expressed by basophils
A
- LFA-1
- Mac-1
- CD44
12
Q
Eosinophils differentiate from myeloid precursor cells in response to _____, _____, and _____
A
- IL-3
- IL-5
- GM-CSF
13
Q
how do eosinophils destroy pathogens?
A
release the toxic substances in their granules
14
Q
What is the most numerous innate immune cell?
A
Neutrophil
15
Q
How do you estimate the number of circulating neutrophils?
A
Absolute neutrophil count (ANC)
16
Q
What are two circumstances that may cause high ANC?
A
Kidney failure
bacterial infection
17
Q
What circumstance could cause ANC to be low?
A
Leukemia or bone marrow damage
18
Q
what is neutropenia?
A
low number of neutrophils
19
Q
Where are mast cells generated?
A
Bone marrow
20
Q
What are the 2 types of mast cells?
A
- connective tissue mast cells
2. mucosal mast cells
21
Q
Where are mucosal mast cells found?
A
areas of the body that are exposed to external environment
22
Q
T/F. Mast cells are important for defense against parasites
A
T
23
Q
How do mast cells in tissue mediate allergic reactions?
A
releasing inflammatory mediators like histamine
24
Q
4 examples of monocytes
A
Osteoclasts
microglia cells
histiocytes
kupffer cells
25
What induces engulfment and degredation of bacteria during phagocytosis?
binding of bacteria to phagocytic receptors on macrophage
26
After activation macrophages do what?
coordinate an immune response
27
T/F. Macrophages can present antigens to lymphocytes?
T
28
Innate immune cells that recognize and kill virus- infected cells or tumor cells
NK cells
29
T/F NK cells belong to both the innate and adaptive immune system
T
30
What is the purpose of the granules inside NK cells
form holes in the target cell
31
What are the two responsibilities of NK cells?
1. Cytolytic effector
| 2. Regulators of immune response
32
Specialized sentinel cells that constantly sense and respond to their immediate environment.
Dendritic cells
33
What are the 2 functions of activated dendritic cells?
1. Antigen uptake in peripheral sites
| 2. Antigen presentation
34
What are the 3 possible sites for dendritic cell maturation
1. bone marrow
2. lymphoid
3. non-lymphoid tissues
35
Which cells are responsible for bridging the gap between the innate and adaptive immunity? and promote self tolerance
DC
36
What is the function of DCs?
To capture, process, and present antigens to t cells
37
What are the 2 classifications of Dendritic cells?
1. Classical/Conventional DCs (cDCs)
| 2. Plasmacytoid DCs (pDCs)
38
Which type of DC has the ability to secrete lg amts of type I interferons upon activation through TLR7 and TLR9
pDCs
39
2 types of lymphocytes
1. B Lymp.
| 2. T Lymp.
40
Where do B cells mature?
Bone marrow, bursa of fabricius
41
When are B cells activated?
When bind antigens throur BCR
42
Which lymphocytes are responsible for generating antibodies to specific antigens?
B cells
43
What are the 3 major roles of Antibodies?
1. neutralization
2. opsonization
3. complement activation
44
Occurs when pathogen is covered in antibodies and cannot further infect host cells
Neutralization
45
When an antibody-bound pathogen serves to alert immune cells to engulf and digest the pathogen
opsonization
46
Process for directly destroying or lysing pathogens
Complement activation
47
What are the precursors to T cells?
Thymocytes
48
Where do t cells mature
Thymus
49
What are the 2 categories of T cells?
1. CD8
| 2. CD4
50
what is another name for CD8 t cells
Cytotoxic t cells
51
Which category of t cells have cytotoxic granules containing cytotoxins that kill target cells?
CD8
52
Which type of T cell recognize and kill infected or cancer cells
CD8
53
What are the 4 types of CD4 T cells?
1. Th 1
2. Th2
3. Th17
4. Treg
54
What is the purpose of Th1 CD4 T cells?
Coordinate immune response against intracellular pathogens
55
How does Th1 cells respond to intracellular pathogens?
produce and secrete cytokines that alert and activate immune cells (macrophages)
56
What is the purpose of TH2 CD4 T cells
Coordinate IR against extracellular pathogens
57
What cells do Th2 cells alert when releasing IL-4 and IL-5?
1. B cells
2. Mast cells
3. Granulocytes
58
What do Th17 cells release in order to activate immune and non immune cells?
IL-17
59
Which category of T cells protect the surfaces (skin, gut) against extracellular bacteria?
Th17
60
T cells that monitor and inhibit the activity of other t cells?
Tregs (regulatory t cells)
61
2 ways immune cells communicate
1. cell to cell contact
| 2. secreted signaling molecules
62
2 places receptors can be expressed
1. on cell surface
| 2. intracellular compartments
63
molecules that activate receptors
ligands
64
2 places ligands are found
free floating or membrane bound
65
Small proteins with diverse function such as cell growth and activation
Cytokines
66
Expressed on innate immune cells, like macrophages and DC, they recognize general microbial patterns essential for innate immune cell activation and inflammatory responses
TLRs
67
What is the function of BCRs and TCRs
recognize foreign antigens
68
Function as carriers to present antigens on cell surfaces, also signal whether a cell is a host cell or a foreign cell
MHC proteins
69
Where are lymphoid cells first produced?
yolk sac, fetal omentum, liver
70
What are the two types of lymphoid organs
1. primary
| 2. secondary
71
what are the primary lymphoid organs
bone marrow, thymus, bursa of fabricius
72
What are the secondary lymphoid organs
spleen, lymph nodes, peyer's patches
73
Organs that regulate the development of lymphocytes
primary lymphoid organs
74
Which part of the thymus contains the thymocytes (lymphocytes)?
Cortex
75
Where do T lymphocytes learn to differentiate foreign from self antigen?
Thymus
76
What happens to t lymphocytes that react to self?
apoptosis- negative selection
77
Where do cells that recognize MHC II/Ag complexes go after positive selection?
To secondary lymphoid organs
78
List some hormones responsible for regulating the maturation process of T lymphocytes
1. Thymosins
2. Thymopoietins
3. Thymulin
4. Thymostimulins
79
What is located in the cortex of the bursa of fabricius?
1. Lymphocytes
2. Plasma cells
3. Macrophages
80
What are the 3 functions of the Bursa of Fabricius?
1. Maturation of antibody forming cells
2. Differentiation of antibody forming cells
3. Negative and positive selection of B lymphocytes
81
What are the 2 categories of secondary lymphoid organs?
1. Encapsulated
| 2. Non Encapsulated
82
What is the function of lymph nodes?
Filters Lymph to trap antigens
83
What are the 3 parts of the lymph node?
1. Cortex
2. Paracortex
3. Medulla
84
What part of the lymph node are b lymphocytes found?
germinal centers of the cortex
85
What part of the lymph node are t lymphocytes and DCs found
Paracortex
86
The principle function of ______ is to facilitate the interaction b/t DCs and T and B lymphocytes
LN
87
What does the immune system do?
a. It helps you breath
b. it helps move the blood through the body
c. fights infectious diseases
d. none of above
c. Fights infectious disease
88
In what part of the body are the white blood cells made?
a. Bone marrow
b. Spleen
c. Lymph Node
d. Pancreas
A. Bone marrow
89
T/F. Macrophages and neutrophils play a role in innate immunity.
T
90
Which of the following is not a phagocyte?
a. Mast cell
b. DC
c. NK cell
d. Neutrophil
c. NK cell
91
All of the following cells are phagocytic except:
a. Eosinophils
b. Basophils
c. Macrophages
d. Neutrophils
e. Lymphocytes
e. Lymphocytes
92
Precursors of macrophages are called:
a. Monocytes
b. Killer cells
c. T cells
d. B cells
a. Monocytes
93
Mast cells. . .
a. Migrate to the thymus to mature
b. mediate inflammatory response in connective tissue
c. secrete antibodies in response to antigens
d. Are monospecific and recognize only a specific antigen
b. Mediate inflammatory response in CT
94
Neutrophils. . .
a. are part of innate immune system response
b. Mature in the thymus
c. Secrete antibodiesin response to antigens
d. are professional antigen presenting cells
a. part of innate immune response
95
Which of the following cells participate in the non-specific defense response when the body is invaded by microbes
a. Neutrophils
b. NK cells
c. Macrophages
d. All of above
d. All of above
96
Which one of the following is not a CD4+ T cell subset?
a. Th1
b. Th2
c. Th17
d. CTL
d. CTL
97
Which of the following T cell types can lyse cells that have been infected with a virus?
a. Helper T cells
b. T regulatory Cells
c. Cytotoxic T cells
d. All of above
c. Cytotoxic T cells
98
What are the 2 types of tissue found in the spleen?
Red and white pulp
99
What does the red pulp of the spleen do?
Filters blood and RBC storage
100
What does the White pulp of the spleen do?
Where immune induction occures
101
Which part of the spleen is rich in lymphocytes?
White pulp
102
Non encapsulated lymphoid tissue located in the wall of the small intestines
Peyer's patches (PP)
103
Why are PP different in ruminants, pigs, dogs, and rabits?
located in the Ileum, and are primary lymphoid organs, where b cells develop
104
T/F. Peyer's patches contain only B lymphocytes?
T
105
What does MALT stand for?
Mucosal-Associated Lymphoid Tissue
106
What is the Significance of GALT?
it is the inductive and effector site of intestinal immune responses
107
Immune cells that belong to the lymphoid lineage, but do not express antigen specific receptors (no TCR or BCR)
Innate lymphoid cells (ILCs)
108
Where are innate lymphoid cells localized to?
Mucosal surfaces
109
What is the purpose of ILCs?
Secrete cytokines
110
What are the 3 groups of ILcs?
1. Group 1 ILCs
2. Group 2 ILCs
3. Group 3 ILCs
111
Group 1 ILCs are under the control of ____
T-Bet Transcription factor
112
What is included in Group 1 ILCs?
NK cells and ILC1 cells
113
What 2 transcription factors are found in group 2 ILCs?
1. GATA-3
| 2. ROR-alpha
114
What two transcription factors are found in group 1 ILCs?
1. INF-Gamma
| 2. TNF-alpha
115
Cytokines are released by group 1 ILCs in response to _____
intracellular pathogens
116
Group 2 ILCs produce ___. ___, and ____ in response to extracellular parasite infections
IL-5, IL-9, and IL-13
117
Group 3 ILCs are under the control of _____ transcription factor.
ROR-yt
118
What is included in Group 3 ILCs?
Lymphoid tissue inducer cells (LTi) and ILC3 cells
119
What is the importance of LTi cells?
required for the development of lymphoid tissues
