MODULE 2 - ORGANS AND CELLS OF THE IMMUNE SYSTEM Flashcards
(115 cards)
1
Q
Define immune system.
A
A network of cells, tissues, and organs that work together to protect the body from infection.
2
Q
Give some functions of immune system.
A
- Protect the body from pathogens (intra/extracellular)
- Eliminate modified or altered self
- Defend the body against the growth of tumor cells
- Homeostatis
3
Q
This is the source of lymphocytes.
A
Stem cells (bone marrow)
4
Q
Give the function of primary or central lymphatic organs.
A
- Site of antigen
- Independent proliferation and differentiation to T- and B- lymphocytes
* e.g. thymus, bursa
5
Q
Give the function of secondary peripheral lymphatic organs.
A
- Lymphocyte proliferation
- Exposure to antigen
6
Q
What are the effector cells?
A
T and B lymphocytes
7
Q
Lymphoid organs are classified on the basis of their roles which includes? (Hint: 3 answers)
A
- Generating lymphocytes
- Regulating production of lymphocytes
- Providing an environment for trapping foreign antigens
8
Q
Primary lymphoid organs develop in puberty phase. True or False?
A
False
9
Q
Bone marrow responds to antigenic stimulation, thus they enlarge. True or False?
A
False
10
Q
As animal develop, newly produced immature lymphocytes migrate from the _____ to the ____.
A
bone marrow; primary lymphoid organs
11
Q
Give the location of thymus.
A
- Located in the thoracic cavity in front and below the heart
- It also extends up to the neck as far as the thyroid gland in horses, cattle, sheep, pigs, and chickens
12
Q
The relative size of thymus is greatest in ?
A
newborn
13
Q
Which has more lymphocytes? Thymic cortex or medulla?
A
Thymic cortex
14
Q
These are round-layered bodies found within the medulla in which it may contain immunoglobulin A in cattle; had cytoplasmic keratinization in some species.
A
Thymic/Hassall’s Corpuscles
15
Q
Thymus has both afferent and efferent lymphatics. True or False?
A
False
16
Q
The thymus shrinks as the animal ages and is gradually replaced by ____.
A
fat
17
Q
Give the main function of thymus.
A
Takes in immature T cells and puts out mature (immunocompetent) T cells
18
Q
A
19
Q
T cells that enter the thymus undergoes a two-stage selection process particularly in the thymic medulla. What are these?
A
- thymocytes with receptors that bind self-antigens that could
cause autoimmunity are killed by apoptosis (negative selection) - thymocytes with receptors that cannot react to any processed
antigen are also killed
20
Q
What are 5 hormones secreted by thymus?
A
- Thymosins
- Thymopoietins
- Thymic humoral factor
- Thymulin
- Thymostimulins
21
Q
This is a zinc-containing peptide which can partially restore T-cell function.
A
Thymulin
22
Q
What is the essential mineral for the development of T cells?
A
Zinc
23
Q
This is a round sac located just above the cloaca.
A
Bursa of Fabricius
24
Q
Bursa of Fabricius reaches its greatest zie in the chick at ?
A
1-2 weeks
25
What are the most prominent cells in Bursa?
Lymphocytes, macrophages, and plasma cells
26
These are lymphoid organs located in the walls of the small intestine.
Peyer's Patches
27
In ruminants, pigs, horses, dogs, and humans, 80-90% of Peyer’s patches are found in the ____.
ileum
28
Peyer's patches contains both B and T cells. True or False?
False, only B cells
29
In rabbits and rodents, Peyer's patches are located in ?
Random intervals in the ileum and jejunum
30
These are also the accumulations of lymphoid tissue in the lamina propria of intestinal wall which allow the transport of antigen into lymphoid tissue.
M cells
31
Ileal peyer's patches in ____ resembles that in avian bursa.
sheep
32
Approximately how many percentage of B cell undergo apoptosis in Peyer's patches?
95%
33
Describe the color of bone marrow in young and adult.
Young - red
Adult - yellow
34
Primary and secondary lymphoid organs both enlarge in response to antigenic stimulation. True or False?
False
35
Bone marrow is the site of ?
Hematopoiesis, B cell maturation and selection
36
These are cells that trap and process antigens and lymphocytes that mediate the immune responses.
Dendritic cells
37
These are round or bean-shaped filters on lymphatic vessels to trap antigens carried in the lymph.
Lymph nodes
38
Depression on the convex side of the lymph node is called ?
Hilum
39
Region in the lymph node where B cells predominate and are arranged in nodules
Peripheral cortex
40
Region in the lymph node where T cells and dendritic cells or antigen presenting cells predominate
Paracortex
41
Region in the lymph node where reticulum cells, dendritic cells, macrophages, B cells and plasma cells are arranged in cellular cords
Central medulla
42
Organ that filters blood and removes both antigenic particles and aged blood cells
Spleen
43
Part of the spleen where RBC are stored; for antigen trapping
Red pulp
44
Part of the spleen where the immune response occurs; rich in lymphocytes
White pulp
45
About how many ml of blood are stored in the spleen?
30-40 ml
46
About ___% of all blood platelets of the body are stored in the spleen.
30
47
This is the largest mass of secondary lymphoid tissue in an adult
Bone marrow
48
Give the cells that are under myeloid lineage.
1. Neutrophils
2. Eosinophils
3. Basophils
4, Monocytes
5. Mast cells
6. Megakaryocytes
7. Erythrocytes
49
Basophils take up __ dye.
basic
50
Eosinophils take up ___ dye.
acidic
51
Neutrophils take up ___ dye.
neither basic nor acidic dyes
52
Blood cell that act as the first line of defense
Neutrophils
53
Neutrophils dies at an average of ___ days after leaving the bone marrow.
5 days
54
After formation in the bone marrow and migrating to bloodstream, neutrophils move into the tissue in about ___ hrs.
12
55
This blood cell constitutes about 60-70% of the blood leukocytes in most carnivores and humans; 50% in horse, and 20-30% in ruminants.
Neutrophils
56
What are the enzymes produced by neutrophils?
1. Lysozyme
2. Proteases
3. Myeloperoxidase
4. Defensins
57
These are second population of cells that serve as "backup system"
Macrophages
58
Which one has faster response? Macrophage or neutrophils?
Neutrophils
59
Which one has greater antimicrobial abilities? Neutrophils or macrophage?
Macrophage
60
These are immature macrophages that forms about 5% of the total WBC population.
Monocytes
61
These are receptors of macrophages that can invading bacteria and then respond by producing cytokines (e.g. IL 1 and TNF-a).
Toll-like receptors
62
Macrophages are attracted to?
1. Bacterial products
2. Product of complement activation
3. Molecules released from damaged cells and tissues
63
Both macrophage and neutrophils can undertake sustained, repeated phagocytic activity. True or False?
False, only macrophages
64
Macrophage can have 2 shapes at max. True or False?
False
65
Monocytes circulate about ___ days in the blood before entering tissues.
3
66
Monoctye/macrophage form about ___% total leukocyte population.
5%
67
Eosinophils are non-motile. True or False?
False
68
Eosinophils express receptors for what Ig?
IgE
69
Growth and differentiation of eosinophils are stimulated by ?
Th cytokine IL-5
70
All of the granulocytes are phagocytic. True or False?
False
71
These are circulating counterparts of mast cells.
Basophils
72
Basophils has high affinity for what Ig?
IgE
73
These are effector cells of IgE.
Basophils
74
Lymphoid lineage includes what cells?
1. T cells
2. B cells
3. NK cells
75
What are the 2 major types of lymphocytes?
T and B cells
76
T cells will leave the thymus and accumulate in what body structures?
1. Paracortex of lymph nodes
2. Periarteriolar lymphoid sheaths of the spleen
3. Peyer's patches
77
T cells account for how many percent of the lymphocytes in the blood?
40-80%
78
What are the functional types of T cells?
1. T helper cells
2. Effector/cytotoxic T cells
3. Suppressor/regulatory T cells
4. Delayed hypersensitivity T cells
79
This is the commander in chief of the immune system.
T helper cells
80
T helper cells (CD4) can respond to a foreign antigen only when the antigen is presented in association with an appropriate ____ ____.
MHC molecule
81
T helper cells (CD4) can identify the enemy in conjunction with ?
MHC class II
82
T helper cells (CD4) has 2 types. Which one is for viral or bacterial attack?
Th1
83
T helper cells (CD4) has 2 types. Which one is for parasitic infection?
Th2
84
They can kill other cells that are perceived as foreign/abnormal - intracellular pathogens.
Effector/Cytotoxic T cells (CD8)
85
Effector/Cytotoxic T cells (CD8) can recognize endogenous peptides with ____.
MHC class I
86
Effector/Cytotoxic T cells (CD8) can kill their target by releasing a protein ____ inducing apoptosis.
perforin
87
Suppressor or regulatory T cells is otherwise known as ?
CD8
88
These type of T cells can stop the activities of B and other T cells.
Suppressor or regulatory T cells/CD8
89
These T cells are primarily important against cancer.
Delayed hypersensitivity T cells
89
This type of T cells are associated with certain allergic reactions and with the rejection of transplanted tissues or organs.
Delayed hypersensitivity T cells
90
Each T-cells has about ____ antigen receptors (TCR's).
30,000
91
Other term for T-cell antigen receptors
Antibody-like heterodimers
92
The complex structure of T-cell antigen receptors consists of 6 glycoproteins. Describe the function of these glycoproteins. (with accordance to their specificity)
* 2 glycoproteins - bind to antigen
* 4 glycoproteins - amplify the signal generated by antigen binding and transit to the cell
93
B-lymphocytes may mature outside bone marrow. True or False?
True
94
B cells are found in what body structures?
* Cortex of lymph nodes
* Follicles within PP
* Spleen (white pulp)
95
B cells account for how many percent of blood lymphocytes?
10-50%
96
B cells has 2 fates. Which one is a precursor for antibodies?
Plasma cells
97
B cells has 2 fates. Which one is a reserve of antigen sensitive cells to be called on when the body is re-exposed to antigen?
Memory B cells
98
Most memory B cells experienced somatic mutation. What specific genes of B cells do extensive mutation occur?
V genes
99
B cell antigen receptor of B cells is how many in numbers?
200k - 500k
100
BCR's and TCR's can bind to antigens when released from their cell surface. True or False?
False, only BCR's
101
These are simply soluble forms of BCR secreted into body fluids.
Antibodies/Ig
102
NK cells undergo thymic processing. True or False?
False
103
NK cells are part of acquired immunity. True or False?
False, innate
104
These are cells that are relatively large and contain an extensive cytoplasm and abundant cytoplasmic granules.
NK cells
105
NK cells kill certain types of tumor cells, viral infected cells with prior sensitization. True or False?
False, w/out prior sensitization
106
NK cells kill certain types of tumor cells and viral infected cells via ?
Secretion of perforin molecules and expression of Fas ligand protein that interact with Fas on the surface of the target causing cell apoptosis
107
These are accessory cells in the induction of immune response.
Dendritic cells
108
Dendritic cells can originate from either myeloid or lymphoid precursors. True or False?
True
109
Dendritic cells are called as such because?
They have relatively small cell body and many long cytoplasmic processes (dendrites); star-shaped
110
There are 5 types of dendritic cells. Identify the type with the given data:
* Present in the interstitium of most organs, T cell-rich areas of lymph nodes, spleen, epidermis of skin
* Present antigen to CD4+ Th cells (Antigen Presenting cells)
* Langerhans cells pick up antigens entering the skin, transport antigen draining lymph node
Integrating dendritic cells
111
There are 5 types of dendritic cells. Identify the type with the given data:
* Not derived from bone marrow precursors, unrelated to interdigitated dendritic cells
* Present in the germinal centers of lymphoid follicles of lymph nodes, spleen, and mucosal lymphoid tissues
* Trap antigen complex to antibody/complement and
display these antigens for recognition by B cells
Follicular dendritic cells
112
There are 5 types of dendritic cells. Identify the type with the given data:
* Found in the epidermis and mucous membranes that trap and process antigens that penetrate the skin
* Influence the development of skin immune responses such as delayed hypersensitivity and allergic contact dermatitis
Langerhans cells
113
There are 5 types of dendritic cells. Identify the type with the given data:
* Include those in blood, which constitute 0.1% of the blood leukocytes.
Circulating dendritic cells
114
There are 5 types of dendritic cells. Identify the type with the given data:
* Populate most organs (e.g. heart, lungs, liver, kidney, GIT)
Interstitial dendritic cells
