IS Lymphocytes and Lymphoid Organs Flashcards
(75 cards)
1
Q
- primary cell involved in the immune response
- matures in the primary lymphoid organs
A
Lymphocytes
2
Q
?% of circulating WBCs does lymphocytes represent
A
20-40%
3
Q
size of lymphocytes?
A
7-10 um
4
Q
round; large, w/ dense chromatin that stains deep blue
A
Nucleus
5
Q
sparse, few organelles, no specific granules, light blue staining
A
Cytoplasm
6
Q
what are the primary lymphoid organs?
A
Bone Marrow and Thymus
7
Q
- primary site of hematopoiesis
- site of B cell development
- main source of HSCs
A
Bone Marrow
8
Q
- found in the thorax, inferior to the thyroid gland and anterior to the heart
- site of T cell development
A
Thymus
9
Q
- where lymphocytes spends most of its lifespan
- sites of antigen-dependent lymphopoiesis
A
Secondary Lymphoid Organs
10
Q
- indiscriminate filter of the blood
- largest secondary lymphoid organ
A
Spleen
11
Q
where is the spleen located?
A
Upper left quadrant of the abdomen
12
Q
graveyard of old and dying RBCs
A
Red Pulp
13
Q
contains lymphoid tissues arranged around arterioles in a periarteriolar lymphoid sheath (PALS)
A
White Pulp
14
Q
- Main function: filtration
- central collecting points for lymph fluid from adjacent tissues
- located along lymphatic ducts
A
Lymph Nodes
15
Q
main function of lymph nodes?
A
Filtration
16
Q
found in gastrointestinal, respiratory, and urogenital tracts
A
Mucosa-associated lymphoid tissue (MALT)
17
Q
responds to pathogens entering the respiratory and alimentary tracts
A
Tonsils
18
Q
association of intra-epidermal lymphocytes (mostly T cells)
A
Cutaneous-associated lymphoid tissue
19
Q
antigen contact in the lymph nodes leads to lymphocyte proliferation and activation of other cells, causing lymphadenitis
A
Lymphadenopathy
20
Q
- rearrangement of genes that code for the heavy & light chains
- antigen-independent phase
A
Pro-B cell
21
Q
what chromosome?
heavy chain
A
Chromosome 14
22
Q
what chromosome?
light chain
A
Chromosome 2 and 22
23
Q
systhesis of heavy chain in?
A
cytoplasm
24
Q
expresses μ heavy chain associated with 2 “surrogate light chains”
A
Pre-B cell
25
* complete IgM on cell surface
* self-antigens send a negative signal to these cells
* self-reactive cells are destroyed by apoptosis
Immature b cell
26
what kind of signal is sent to the cells by self-antigens?
Negative
27
rearrangement of genes in either what chromosome?
Chromosome 2 or 22
28
* they mature as marginal zone B cells or follicular B cells
* expresses IgD
Mature Naive B cell
29
marginal zone B cells reamin where?
Spleen
30
migrates to lymph nodes and other lymphoid organs
Follicular B cells
31
where does follicular B cells migrate?
lymph nodes and other lymphoid organs
32
* spherical or ellipsoidal cells
* eccentric nucleus, heavily clumped chromatin
* found either in the bone marrow or germinal centers
Plasma cells
33
produce cytokines allowing plasma cells to be long-lived
Stromal cells in Bone Marrow
34
size of plasma cells
10-20 um
35
B cell development
1. Pro B cell
2. Pre B cell
3. Immature B cell
4. Mature B cell
5. Activated B cell
6. Plasma cell
36
Stages of T cell differentiation
1. Double negative Thymocyte
2. Double Positive Thymocyte
3. Single Positive Thymocyte
4. Mature Naive T cells
5. Activated T cells
37
* actively proliferate in the outer cortex under the influence of IL-7
* rearrangement of TCR gene begins here
Double-negative thymocytes
38
thymocytes lack?
CD4 and CD8
39
* express both CD4 and CD8 surface markers
* rearrangement of alpha chain genes begin here
Double-positive thymocytes
40
thymocytes with functional TCR-CD3 complex will be allowed to survive
Positive Selection
41
selection of thymocytes that will interact with host cell MHC molecules
MHC Selection
42
* only 1-3% of thymocytes survive here
* negative selection and clonal deletion occurs here
Single-positive thymocytes
43
thymocytes with strong reactions with self-peptides other than MHC antigens are eliminated through apoptosis
Negative selection
44
the process of eliminating clones of T cells that is capable of an autoimmune response
Clonal deletion
45
?% of thymocytes survive?
1-3%
46
* exhibit only 1 type of marker (CD4 or CD8).
* have a lifespan of several years
Mature naive T cells
47
mature naive T cells exhibit only 1 type of marker ? or ?
CD4 or CD8
48
mature naive T cells reticulates every?
12-24 hours
49
CD4+ T cells (T helper cells) reacts wt?
MHC class II
50
CD8+ T cells (T cytotoxic cells) reacts wt?
MHC class I
51
Heterodimer of two polypeptide chain (alpha and beta) covalently bonded by disulfide bonds
T Cell Receptor
52
heterodimer of 2 polypeptide chain by T cell receptor are?
Alpha and Beta Chain
53
T cell receptor are expressed by both?
CD4 and CD8
54
rearrangement of beta chain?
Chromosome 7
55
rearrangement of alpha chain?
Chromosome 14
56
group of proteins that are physically associated with TCR?
CD3 complex
57
consists of a delta chain, gamma chain, zeta chains
CD3 complex
58
ensures cell surface expression of TCR
CD3 complex
59
3 types of chains that consists of CD3 complex
Delta chain, Gamma chain, Zeta chains
60
presenting antigens from intracellular pathogens
MHC class I molecule
61
presenting antigens from extracellular pathogens
MHC class II molecule
62
proliferate and produce cytokines
CD4 T cells
63
* antigen specific
* bind and kill infected cells by inducing apoptosis
CD8 T cells
64
2 signals that B cell requires
1. Ag-sIg crosslinking
2. B cell-Th cell binding through TCR and CD40 (B) and CD40L (T)
65
* activated B cells express CD25 (for IL-2)
* migrates either to T cell zone or B cell follicles
* leads to formation of plasma cells and memory B cells
Responses to TC-dependent antigens
66
* elicits antibody formation in the absence of T cell help
* produces IgM only
* almost no production of memory B cells
Responses to TC-independent antigens
67
antibody kinetics to TC dependent antigens phases?
1. Lag/Inductive/Latent
2. Log/Exponential
3. Plateau/Steady-state
4. Decline/Decay
68
* gold standard in identifying lymphocytes
* uses labeled monoclonal antibodies against surface markers
Flow Cytometry
69
CD2, CD3, CD4, CD8
T cells
70
CD19, CD21, CD22, sIg
B cells
71
activates cytotoxic lymphocytes and macrophages
Th1
72
help B cells produce antibodies
Th2
73
produces IL-9 (proinflammatory)
Th9
74
produces IL-17 and IL-22 (increase inflammation and joint destruction).
Th17
75
suppresses immune responses to self-antigens.
T regulatory cell (Treg)
