Lecture 2 - Cells and Tissues of the Immune System Flashcards
1
Q
What is a leukocyte
A
white blood cell
2
Q
what is a lymphocyte
A
type WBC (T cell, B cells, NK cell)
3
Q
What type of nucleus do granulocytes have
A
polymorphonuclear; mutli-lobed nucleus
4
Q
What type of nucleus do mononuclear cells have
A
single rounded nucleus
5
Q
Examples of granulocytes
A
neutrophils, eosinophils, basophils
6
Q
Examples of mononuclear cells
A
lymphocytes, monocytes
7
Q
Which mononuclear cells are phagocytic
A
monocytes
8
Q
Which mononuclear cells are not phagocytic
A
lymphocytes
9
Q
What cells are important in blood clotting
A
platelets
10
Q
What percentage of WBCs in circulation are basophils
A
0.5%
11
Q
What granulocytes take up acid dyes
A
eosinophils
12
Q
What granulocytes take up little dye
A
neutrophils
13
Q
What granulocytes take up basic dyes
A
basophils
14
Q
What is the half-life of basophils
A
1-2 days
15
Q
What are granules in basophils filled with
A
inflammatory mediators
16
Q
What type of infections are basophils important in
A
allergy and parasitic infections (secondary to eosinophils)
17
Q
What granulocytes may be mast cell precursors
A
basophils
18
Q
What percentage of WBCs in circulation are eosinophils
A
1-3%
19
Q
What is the half-life of eosinophils
A
30 minutes
20
Q
What are granules in basophils filled with
A
potent mediators (major basic protein and eosinophilic cationic protein) capable of killing parasites
21
Q
How long do eosinophils live in tissues
A
couple of weeks
22
Q
What are eosinophils important in controlling
A
extracellular parasites
23
Q
What percentage of WBCs in circulation are monocytes?
A
3-7%
24
Q
What is the half life of monocytes
A
1-2 days then migrate to tissue and differentiate into a macrophage
25
What WBCs are found in most tissues and are extremely important in immune response
macrophages
26
What do monocytes differentiate into
macrophages
27
How are macrophages important in the immune response?
1. phagocytosis and killing of bacteria
2. presentation of antigen by APCs on MHC II
3. secretion of cytokines
28
Major role of cytokines
major role in inflammation and immune response
29
What is the order of how WBCs arrive at infection
neutrophils, monocytes/macrophages
30
What is a sign of chronic infection
accumulation of monocytes/macrophages at the site of infection
31
What % of WBC in circulation are neutrophils
55-90%
32
Half life of neutrophils in general
1-2 days
33
Half life of neutrophils in blood
8-10 hrs
34
How often are neutrophils replaced by new ones
2.5x per day
35
What spends a lot of energy making neutrophils
bone marrow
36
What are the first responders to infection and how fast do they arrive in substantial numbers
neutrophils, within 4 hours
37
Where do neutrophils exit the blood stream
at the site of infection
38
What do neutrophils do after arriving at the site of infection
accumulate in large numbers to ingest and kill the pathogen
39
What increases the production of neutrophils
bone marrow in response to bacterial infection
40
What is neutrophilia
increase in number of neutrophisl
41
What is commonly seen in animals with bacterial infections
neutrophilia
42
How is pus formed
neutrophils attack and destroy pathogens, especially bacteria and fungi, and die in the process
43
What is neutropenia
lower than normal numbers of neutrophils in the blood stream
44
What is commonly seen in animals with viral infections
neutropenia
45
What % of WBCs in circulation are lymphocytes
20-35%
46
What are types of lymphocytes
B cells, T cells, NK cells
47
HAlf life of lymphocytes
120 days
48
Where do lymphocytes circulate
between blood and lymphoid tissues searching for antigens
49
What is unique about lymphocytes
they circulate between blood and lymphoid tissues searching for antigens; other WBC stay in tissues once exiting blood
50
What lymphocytes can't be distinguished morphologically
naive B and T cells
51
When do B and T cells die
when they do not come into contact with their antigen they recognize
52
What happens when B and T cells meet their antigen
they get activated and some differentiate into memory cells
53
What is a cognate antigen
the antigen B and T cells are looking for
54
What do guard cells under epithelial cells do
recognize pathogens and secrete cytokines that act on endothelial cells->start showing receptors->signal neutrophils
55
What are important for regulating leukocytic traffic
endothelial cells
56
Wha are addressins
adhesion molecules on endothelial cells that allow circulating leukocyte to know where they are in body
57
When are addressin upregulated
during infection to faciliate binding of neutrophils to the endothelial cells and their subsequent exit to the site of infection
58
What do monocytes differentiate into
macophages and dendritic cells
59
All immune cells originate from ...
bone marrow
60
What are the three lineages of immune cells
1. erythroid
2. myeloid
3. lymphoid
61
Erythroid lineage
RBCs, platelets
62
Myeloid lineage
monocytes, neutrophils, eosinophils, basophils, some dendritic cells, mast cells
63
What cells are important in initiation of immune response
myeloid dendritic cells
64
lymphoid lineage
B cells, T cells, NK cells, some dendritic cells
65
What myeloid cells are released in a mature state
granulocytes
66
What myeloid cells migrate to tissues and mature
dendritic cells
67
What myeloid dendritic cells are important to initiating immune response
sentinel cells and APC
68
What myeloid cells leave bone marrow and mature in tissues and live from weeks to months and are important in parasitic infection and allergies
mast cell precursors
69
What types of infection are mast cell precursors important for
parasitic
70
T lymphocytes are released immature from bone marrow as pre-T cells and go to the ______ to mature
thymus
71
In the thymus, a T cell receptor is generated by _____
DNA rearrangement
72
What happens if the newly generated receptor recognizes antigen in thymus?
its eliminated
73
What happens if the newly generated receptor recognizes MHC molecule bu tnot antigen?
T cell matures and goes to secondary lymphoid tissue
74
B lympocytes are released immature from bone marrow as pre-B cells, which mature in _____??
primary lymphoid tissue
75
Where do B lymphocytes in birds mature?
Bursa of Fabricius
76
Where do B lymphocytes mature in mammals?
bone marrow
77
Where do B lymphocytes mature in ruminants
Peyer's patch at ileocecum
78
Where does B cell develop its receptor (BCR)
primary lymphoid tissue
79
What happens if the BCR recognizes an antigen during development
its eliminated
80
What happens if the BCR DOES NOT recognize an antigen during development
it matures and goes to secondary lymphoid tissues
81
Why are NK cells released in the mature state
bc they are part of innate immune system
82
Where are NK cells released from
bone marrow
83
How do NK cells differ from B and T cells
not antigen specific
84
Which lymphoid cells have no memory
NK cells
85
When does differentiation in secondary lymphoid organ occur
when mature, naive B or T cell meets its antigen
86
What do B cells differentiate into
1. effector plasma cells that secrete antibody
2. memory cells which are long lived clones of the cell
87
What do T cells differentiate into
effector cells or memory cells
88
What is the first step of differentitation
clonal expansion of lymphocytes (mitosis)
89
What are primary lymphoid organs
thymus, Bursa, Peyer's patches, bone marrow
90
What are secondary lymphoid organs
tonsils, spleen, lymph nodes, Peyer's patches, bone marrow
91
What type of Peyer's patches do Group I have
small dots in jejunum and long strip in ileum
92
What type of Peyer's patches do Group II have
small dots in both jejunum and ileum
93
What increases chances of lymphocyte meeting its antigen
secondary lymphoid tissue
94
What are lymph nodes
lymphocyte rich tissue connected to lymphatic system, where adaptve immune response to lymph-borne antigen is initiated
95
What is spleen
site for adaptive immune response to blood borne antigens
96
What is MALT
mucosal associated lymphoid tissue, where adaptive immune response to antigens invading from the mucosal surfaces is initiated
97
Which way do primed vs naive lymphocytes go?
primed- towards tissue fluid
naive- towards lymph nodes
