Leukocytes Flashcards
1
Q
Mobile cells that leave the circulation via margination, pavementing, and diapedesis
A
leukocytes
2
Q
What are the 3 ways that leukocytes can leave the circulation?
A
margination
pavementing
diapedesis (aka extravasation)
3
Q
Are leukocytes mobile or immobile?
A
mobile
4
Q
What type of cell is a leukocyte?
A
WBC
5
Q
What process do WBCs use to stick to endothelial cell surface and squeeze between endothelial cells of capillaries and venules?
A
Pseudopodia
6
Q
What attracts leukocytes to inflammatory sites?
A
chemotaxis via cytokines
7
Q
any cell product that influences another cell, like pheromone
A
cytokines
8
Q
Cell that functions as an active part of immune system in tissues
A
leukocytes
9
Q
How are WBCs categorized?
A
granulocytes
agranulocytes
10
Q
“possessing granules”
A
granulocytes
11
Q
“lacking granules”
A
agranulocytes
12
Q
What is the stain of 1’ granules?
A
blue/purple
13
Q
Which WBCs possess 1’ granules?
A
ALL of them
14
Q
What are the granules called that stain blue/purple?
A
1’ granules aka azurophilic granules
15
Q
What do 1’ granules contain?
A
lysosomal enzymes (ex: acid hydrolases)
16
Q
Granulocytes also possess ____ ____ absent in agranulocytes
A
specific granules = 2’ granules
17
Q
Where are 2’ granules found
A
granulocytes ONLY
18
Q
What do 2’ granules contain?
A
lysozyme and alkaline phosphates
19
Q
What is the stain of 2’ granules?
A
variable
20
Q
What are the 3 types of granulocytes?
A
neutrophils
basophils
eosinophils
21
Q
What are the 2 primary characteristics of granulocytes??
A
single, multi-lobed nucleus
prominent cytoplasmic granules
22
Q
What is the most common granulocyte?
A
neutrophil
23
Q
How big are neutrophils compared to RBCs?
A
1.5x size of RBCs
24
Q
How many lobes make up the nucleus of neutrophils and what are those cells called?
A
3-5 lobes
polymorphonuclear cells
25
Are neutrophils long-lived or short-lived and what is the tissue lifespan?
short-lived
| hrs-days
26
How many mitochondria in neutrophils?
few mitochondria = 1' anaerobic glycolysis
27
What type of glycolysis do neutrophils use?
1' anaerobic glycolysis
28
What do the 1' granules of neutrophils contain?
unique antimicrobial myeloperoxidase
29
How do the 2' neutrophils stain?
EITHER basophilic or eosinophilic ("neutral")
30
What do neutrophils contain?
```
inflammatory mediators and complement activators
proteases
defensins
lactoferrin
lysozyme (antibacterial compounds)
```
31
When are neutrophils released and how?
during inflammatory reactions via degranulation
32
Which WBC posses small 3' granules?
neutrophils
33
What do 3' granules contain?
gelatinase
34
What is the function of gelatinase?
breaks down collagen
35
Are neutrophils associated with acute or chronic inflammation? How long does it last?
acute
| several days
36
What are the 4 cardinal signs of inflammation?
rubor
tumor
calore
et dolore
37
rubor
redness
38
tumor
swelling
39
calore
heat
40
et dolore
pain
41
What is the level of motility of neutrophils and how do they move?
highly motile
| amoeboid movement
42
Which WBC uses amoeboid movement?
Neutrophils
43
What are neutrophils attracted to and how?
bacteria and damaged tissue
| chemotactic factors
44
What attracts neutrophils to bacteria and damage tissue?
chemotactic factors
45
What is the primary function of neutrophils?
phagocytosis
46
What does phagocytosis lead to?
formation of phagolysosome to digest bacteria
47
coating of bacteria with antibody and complement to enhance phagocytosis
phagocytosis enhanced via opsonization
48
bacterial killing by generating hydrogen peroxide and hypochlorous acid
respiratory burst
49
Which WBC is involved in opsonization?
neutrophil
50
Which WBC is involved in respiratory burst?
neutrophil
51
Which WBCs involve Stab cells and Barr bodies?
neutrophils
52
immature neutrophils
"Stab" cells (band cells)
| non-segmented nucleus
53
inactive X chromosomes in females
Barr body
54
What is the least common WBC?
basophils
55
How big are basophils compared to RBCs?
2x size of RBC
56
How many lobes do basophils have?
bilobed
57
Which WBC may or may not be equivalent to mast cells in tissue?
basophils
58
What are mast cells characterized by?
large, basophilic SPECIFIC granules
59
What do the specific granules in basophils contain?
```
hydrolytic enzymes
heparin sulfate (anticoagulant)
chondroitin sulfate (proteoglycan)
HISTAMINE
leukotrienes (ECF)
```
60
slow reacting substance of anaphylaxis that causes smooth muscle contraction
leukotrienes
61
How are granule contents released into eosinophilic chemotactic factor (ECF)?
degranulation
62
Degranulation is used is which type of hypersensitivity reactions?
Type 1 (immediate)
63
What are 3 conditions involved with Type 1 hypersensitivity rxns?
asthma
hayfever
some allergic dermatitis
64
Severe hypersensitivity reactions are known as:
anaphylaxis
65
very rapid, severe immune reactions due to "overreactive" basophils:
anaphylaxis
66
What counteracts the effects of basophils?
eosinophils
67
2nd least common WBC
eosinophils
68
How many lobes do eosinophils have?
bilobed
69
Which WBCs are known as looking like "mickey mouse ears"?
eosinophils
70
Which WBCs remain in circulation about 3-6 hours before entering tissue?
eosinophils (lifespan = 8-12 hours)
71
Eosinophils have surface receptors for which antibody?
IgE
72
Which WBC has surface receptors for IgE?
eosinophils
73
What do large eosinophilic specific granules contain?
hydrolytic enzymes
74
What are 4 hydrolytic enzymes in the large eosinophilic specific granules?
- histaminase
- eosinophil peroxidase (EPO)
- lysosomal enzymes
- major basic protein
75
enzyme that neutralizes histamine
histaminase
76
hydrolytic enzyme that neutralizes heparin and kills parasites?
major basic protein
77
Which WBC is important in hypersensitivity reactions?
eosinophils
78
What are eosinophils chemotactically attracted to?
basophils and mast cells via ECF
79
Function of eosinophils
ameliorate and counteract hypersensitivity reactions and effects of histamine
80
How do eosinophils counteract hypersensitivity reactions?
release eosinophil derived inhibitor
81
What does the eosinophil derived inhibitor do?
inhibits basophil and mast cell degeneration
82
Which WBC has antiparasitic function, especially against flukes (helminths) and affinity for Ag-Ab complexes?
eosinophils
83
What destroys parasites and Ag-Ab complexes?
major basic protein and subsequent phagocytosis
84
What are allergy sufferers insufficient in?
eosinophils
85
What are the 2 types of agranulocytes?
monocytes and lymphocytes
86
What does the nucleus of agranulocytes look like?
single, unlobed nucleus
87
What type of granules do agranulocytes have?
1 (azurophilic) granules
88
Do agranulocytes have 2' (specific) granules?
no
89
Largest WBC
monocyte
90
abundant agranulocytes with gray-blue/lavender cytoplasm
monocyte
91
What is the nucleus in monocytes?
large indented ("kidney bean" shaped) nucleus
92
How long are monocytes present in blood?
2-3 days then extravasate
93
What happens to monocytes after they enter tissue?
become macrophages (histiocytes)
94
What is the lifespan of monocytes in tissue?
several months
95
Do monocytes travel or remain in same tissue?
fixed- remain in same tissue
96
Types of monocytes in the body
```
Kupfer cells
microglial cell
Langerhans cells
dust cells
osteoclasts
```
97
Where are Kupfer cells found?
liver
98
Where are microglial cells found?
CNS
99
Where are Langerhans cells found?
skin
100
Where are osteoclasts found?
bone
101
Are monocytes mobile or immobile?
mobile
102
Are monocytes phagocytic?
yes - contain abundant hydrolytic enzymes
103
Monocytes fuse together to become:
(multinucleate) epithelioid giant cells in chronic granulomas
104
cells that function as Ag-presenting cells in lymphoid organs
monocytes
105
WBCs active in subacute and chronic infections and have a lifespan of days to years; include 2 size classes (small and large)
LYMPHOCYTES
106
Do lymphocyte size classes correlate with cell types?
no
107
WBCs characterized by round, densely staining nucleus surrounded by thin rim of cytoplasm
lymphocytes
108
How are lymphocytes characterized?
round, densely staining nucleus surrounded by thin rim of cytoplasm
109
What is the primary cell of the immune system? (recirculating, immunocompetent cells)
lymphocytes
110
what are the 2 major types of lymphocytes?
b-cells
| t-cells
111
Are there more b-cells or t-cells?
t-cells (90%)
112
type of lymphocyte that was first recognized in Bursa of Fabricius of birds
b-cells
113
Where are b-cells formed in mammals?
bone marrow
114
Where do b-cells become immunocompetent?
bone marrow
115
Function of b-cells
HUMORALLY mediated immune response = produce Ab's
116
What happens to b-cells after encountering Ag?
undergo multiple divisions to produce clone of Ab-producing plasma cells called AMPLIFICATION, or CLONAL EXPANSION
117
multiple divisions to produce clone of Ab-producing plasma cells
amplification or clonal expansion
118
What happens to b-cells that DO NOT replicate?
remain as long-lived MEMORY cells or EFFECTOR cells
119
B-cells function in ________ response of _____ immunity; premise of vaccination = prevent disease
anamnestic
| humoral
120
B-cells can also function as __-presenting cells.
Ag
121
Which cells have HLA Type II surface markers & surface immunoglobulins (HLA = human leukocyte Ag—major histocompatibility complex [MHC] molecules)?
b-cells
122
thymus-dependent lymphocytes
t-cells
123
What are t-cells formed?
bone marrow
124
What happens to t-cells after they are formed in bone marrow?
migrate to thymus to become immunocompetent
125
Which lymphocyte is responsible for cell-mediated immunity?
t-cells
126
Are t-cell lifespans long or short?
long
127
What are t-cells responsible for?
cell-mediated immunity
128
T-cells have _____ on cell surface like those present on Ab’s (paratopes)
receptors
129
What is the purpose of paratopes?
recognize foreign proteins of Ag's (epitopes)
130
Which lymphocyte have "cluster of differentiation" determinant molecules (CD molecules) on surface?
t-cells
131
What is the purpose of "cluster of differentiation" determinant molecules (CD molecules?
Recognize HLA receptors on surface of other cells (prevent “self”-destruction)
132
What are the 3 types of t-cells?
cytotoxic
suppressor
helper
133
cytotoxic t-cells are aka:
killer t-cells (Tc/Tk)
134
1’ effectors in cell-mediated immunity—tend to be large lymphocytes (t-cell)
cytotoxic t-cell
135
Recognize cells with foreign surface Ag’s or receptors & kill them (t-cell)
cytotoxic t-cell
136
Punch holes in PMs (t-cell)
cytotoxic t-cell
137
Functions of cytotoxic t-cells:
- 1’ effectors in cell-mediated immunity—tend to be large lymphocytes
- Recognize cells with foreign surface Ag’s or receptors & kill them
- Punch holes in plasma membranes
138
t-cell that detects invaders, sound chemical alarm
helper t-cell (Th)
139
t-cell that recognize Ag, usually presented by Mor b-cell, then secrete lymphokines(cytokines)—act as pheromones, stimulate b-cells => Ab production, or Tk cells => kill
Th
140
Functions of helper t-cells (Th):
- Detect invaders, sound chemical alarm
- Recognize Ag, usually presented by Mor b-cell, then secrete lymphokines(cytokines)—act as pheromones, stimulate b-cells => Ab production, or Tk cells => kill
141
t-cell that suppress activity of b-cells, dampen immune response, especially to “self” molecules
Ts
142
Functions of suppressor cells (Ts)
Suppress activity of b-cells, dampen immune response, especially to “self” molecules
143
t-cell associated with Autoimmune diseases
Ts- loss of control of Ts cells
144
Lymphocytes which possess Fc receptors but lack specific cell surface markers of either b-or t-cells
null cells
145
natural killer cells (NK) are classified as what type of cell?
null cells
146
null cells include:
- natural killer cells (NK)
| - some pluripotent stem cells
147
What are null cells responsible for?
- NONSPECIFIC cytotoxicity against virus-infected and tumor cells
- Ab-dependent, cell-mediated cytotoxicity (ADCC)
148
relative concentrations of WBCs:
NLMEB
149
total # of WBCs =
CBC (complete blood count)
150
relative percentages of WBCs
differentiated cell count
151
increased WBCs indicates:
infection/tumor
152
increased neutrophils =
acute, bacteria
153
increased lymphocytes (& monocytes) =
subacute, viral
154
increased eosinophils =
allergies/parasites
155
decreased WBCs indicates:
immune suppression/tumor
156
acute viral infection or severe sepsis (wbcs)
neutropenia
157
thrombocytopenia is caused by:
decreased platelets
