LEUKOCYTE DEVELOPMENT, KINETICS, AND FUNCTIONS Flashcards
book based (104 cards)
1
Q
relatively colorless compared to red blood cells
A
Leukocytes
2
Q
stain used to see leukocytes
A
Romanowky stain
3
Q
what type of microscope is used to view wbc
A
Light microscope
3
Q
a group of leukocytes whose cytoplasm is filled with granules with different staining characteristics and whose nuclei are segmented or lobulated.
A
Granulocytes
3
Q
granules containing basic proteins that stain with acid stains such as eosin.
A
Eosinophils
4
Q
granules that are acidic and stain with basic stains such as methylene blue.
A
Basophils
5
Q
granules that react with both acid and basic stains, which gives them a pink to lavender color.
A
6
Q
due to nuclear segmentation is quite prominent in mature neutrophils.
A
Polymorphonuclear cells
7
Q
these cells have nuclei that are not segmented but are round, oval, indented, or folded.
A
Mononuclear cells
8
Q
types of mononuclear cells
A
monocytes
lymphocytes
9
Q
where does leukocyte develop
A
hematopoietic stem cell in bone marrow
9
Q
Typical reference interval of leukocyte for adults
A
4.5 x 109/L to 11.5 x 109/L
10
Q
movement of cells through developmental stages
A
Kinetics
11
Q
present in peripheral blood in two forms according to whether the nucleus is segmented or still in a band shape.
A
Neutrophils
12
Q
a common progenitor with monocytes and distinct
from eosinophils and basophils.
A
Granulocyte monocyte progenitor (GMP)
13
Q
major cytokine responsible for the stimulation of
neutrophil production.
A
Granulocyte colony – stimulating factor (G-CSF)
14
Q
Three pools of developing neutrophils in the bone
marrow
A
Stem cell pool
Proliferating pool
Maturation pool
14
Q
pool that is capable of self-renewal and
differentiation.
A
Stem cell pool
14
Q
pool that cells that are dividing and includes common myeloid progenitors.
A
Proliferating pool
14
Q
pool that undergoes nuclear maturation that form the bone marrow reserve and at are available for release.
A
Maturation pool
14
Q
make up 0% to 3% of the nucleated cells in the bone marrow and measure 14-20 um in diameter
A
Myeloblasts
14
Q
has a high nucleus-to-cytoplasm ratio of 8:1 to 4:1. No visible granules when observed under light microscopy with Romanowsky stain.
A
Type I myeloblast
15
Q
shows the presence of dispersed primary granules in the cytoplasm (granules does not exceed 20 per cell).
A
Type II myeloblast
15
Q
have a darker chromatin and a more purple cytoplasm, and they contain more than 20 granules that do not obscure the nucleus. Rare in normal bone marrows, but they can be seen in certain types of acute myeloid leukemias.
A
Type III myeloblasts
15
omprise 1% to 5% of the nucleated cells in the bone marrow. The nucleus is round and is often eccentric. These granules are the first in a series of granules to be produced during neutrophil maturation.
Promyelocytes
15
make up 6% to 17% of the nucleated cells in the bone marrow and are the final stage in which cell division occurs. The production of primary granules ceases and the cell begins to manufacture secondary neutrophil granules.
Myelocytes
16
also known as “dawn of neutrophilia” look very similar to the promyelocytes in size and nuclear
characteristics except that patches of grainy pale pink cytoplasm representing secondary granules.
Early myelocytes
17
slowly spread through the cell until its cytoplasm is
more lavender-pink than blue.
Secondary neutrophilic granules
17
smaller than promyelocytes, and the nucleus has
considerably more heterochromatin. Nucleoli are difficult to see by light microscopy.
Late myelocytes
18
constitute 3% to 20% of nucleated marrow cells. The cells are no longer capable of division and the major morphologic change is in the shape of the nucleus. Synthesis of tertiary granules may begin during this stage.
Metamyelocytes
19
make up 9% to 32% of nucleated marrow cells and 0% to 5% of the nucleated peripheral blood cells. All evidence of RNA is absent, and tertiary granules continue to be formed during this stage.
Bands
20
the middle ground states that when doubt exists, an elevated band count was thought to be useful in the diagnosis of patients with infections.
Segmented neutrophil
21
recommends that bands should be included within
the neutrophil count and not reported as a separate
category.
Clinical and Laboratory Standards Institute (CLSI)
21
make up 7% to30% of nucleated cells in the bone marrow. Secretory granules continue to be formed during this stage. The only morphologic difference between segmented neutrophils and bands is the presence of between 2-5 nuclear lobes connected by thread-like filaments.
Segmented neutrophils
22
Involves the movement of neutrophils and neutrophil precursors between the different pools in the bone marrow, peripheral blood, and tissues.
NEUTROPHIL KINETICS
23
loosely localized to the walls of capillaries in tissues such as the liver, spleen, and lung
Marginated neutrophil pool (MNP)
23
The half-life of neutrophils in the blood
7 hours
23
significant importance in allowing neutrophils to marginate as well as exit the blood and enter the tissues by a process known as diapedesis.
Integrins and selectin
23
are removed by macrophages in the spleen, bone marrow, and liver
apoptosis
23
Spontaneous neutrophil apoptosis is regulated by pro- and antiapoptotic members
B-cell lymphoma 2 family
23
Activation is facilitated by the rolling of neutrophils on endothelium surfaces
Chemokines
24
tend to prolong the neutrophil’s life span through antiapoptotic signals
Myeloid cell leukemia-1 and myeloperoxidase
24
trigger the death and phagocytosis of neutrophils
macrophage-1 antigen
24
major function of neutrophils
phagocytosis and destruction of foreign material and
microorganisms
25
three functions of neutrophils
- Phagocytosis and destruction of foreign
materials
- generation of NETs
- Secretory function
26
degrade the extracellular matrix and act as chemotactic agents for extravasation and migration of additional neutrophils to the site of inflammation.
Tertiary granules
27
extracellular thread-like structures believed to represent chains of nucleosomes from unfolded
nuclear chromatin material. able to trap and kill
gram-positive and gram-negative bacteria as well as
fungi
NETs - neutrophil extracellular nets
27
unique form of neutrophil cell death that
results in the release of NETs.
NETosis
28
make up 1% to 3% of nucleated cells in the bone marrow. An absolute number of up to 0.4 x 109 /L in the peripheral blood.
eosinophils
28
critical for eosinophil growth and survival.
IL-5 and IL-33
28
characterized by the presence of large, pale, reddish orange secondary granules, along with azure granules in blue cytoplasm.
Eosinophil myelocytes
28
can be identified cytochemically because of the presence of Charcot-Leyden crystal protein in their primary granules
Eosinophilic promyelocytes
28
resemble their neutrophil counterparts with respect to their nuclear shape.
Eosinophil metamyelocytes and bands
29
display a bilobed nucleus. Their cytoplasm contains characteristic refractile, orange-red secondary granules.
Mature eosinophils
29
The time from the last myelocyte mitotic division to
the emergence of mature eosinophils from the marrow
3.5 days
30
Third type of granule is generated
secretory granule
31
eosinophils circulating half life
18hrs
32
Survival time of eosinophils in human tissues
2 to 5 days
33
secretory vesicles remove specific proteins from the secondary granules
Piecemeal degranulation
33
granules fuse together within the eosinophil before fusing with the plasma membrane.
Compound exocytosis
33
granules move to the plasma membrane, fuse with the plasma membrane, and empty their contents into the extracellular space
Classical exocytosis
34
full of a large number of previously synthesized proteins, including cytokines, chemokines, growth factors, and cationic proteins.
Eosinophil granules
34
true leukocytes because they mature in the bone
marrow and circulate in the blood as mature cells
with granules
basophils
34
evidently capable of synthesizing granule proteins based on activation signals.
Mature basophils
34
occurs when extracellular intact granules
are deposited during cell lysis.
Cytolysis
35
precursors leave the bone marrow and use the blood as a transit system to gain access to the tissues where they mature.
mast cell
35
life span of basophils
60 hours
35
can induce basophils to produce and release
retinoic acid, a regulator of immune and resident cells in allergic diseases.
Mast cells
35
the effectors of IgE-mediated chronic allergic inflammation, basophils function as initiators of
the allergic inflammation through the release of
preformed cytokines.
Mast cells
35
basophils are activated by what interleukins, antiapoptotic pathways are initiated that prolong the basophil lifespan.
IL-3 and IL-25
35
play a role in angiogenesis through the expression of
vascular endothelial growth factor (VEGF) and its
receptors
mast cells and basophils
36
They are tissue effector cells of allergic responses and
inflammatory reactions.
MAST CELLS
37
major cytokine responsible for the growth and
differentiation of monocytes.
Macrophage colony-stimulating factor (M-CSF)
37
Morphologic stages of monocyte development
Monoblasts
Promonocytes
Monocytes
38
exists in normal bone marrow are very rare and are difficult to distinguish from myeloblasts based on morphology.
Monoblasts
39
12 to 18 um in diameter, and their nucleus is slightly indented or folded
Promonocytes
39
they tend to stick to and spread out on glass or plastic.slightly immature cells whose ultimate goal is to enter the tissues and mature into macrophages, osteoclasts, or dendritic cells.
Monocytes
39
Monocytes remain in the circulation approximately
3 days
39
survive far longer than tissue neutrophils.
Resident macrophage
39
life span measured in hours.
Inflammatory macrophages
40
recognize a wide range of bacterial pathogens by means of pattern recognition receptors (Toll-like receptors) that stimulate inflammatory cytokine production and phagocytosis. they can phagocytize foreign organisms or materials that have been coated with antibodies or complement components.
Innate immunity
40
degrade antigen and present antigen fragments on their surfaces.
Adaptive immunity
40
most efficient and potent of the antigen-presenting cells.
Dendritic cells
40
they develop in the thymus
T cells
40
removal of debris and dead cells at sites of infection or tissue damage.
Housekeeping
40
3 major group of lymphocytes
▪ T cells
▪ B cells
▪ NK cells
40
make up a small percentage of lymphocytes
and are part of innate immunity
NK cells
41
play a major role in adaptive immunity
T and B cells
41
Antibody-producing lymphocytes; they develop in the bone marrow
B lymphocytes
42
develop in both the bone marrow and the thymus
NK cells
43
development occurs in the bone marrow and thymus
Antigen - independent lymphocyte
43
development occurs in the spleen, lymph nodes, tonsils, and mucosa-associated lymphoid tissue such as the Peyer’s patches in the intestinal wall
Antigen-dependent lymphocyte
43
T lymphocytes develop initially in the thymus—a
lymphoepithelial organ located in
upper mediastinum
43
develop initially in the bone marrow and go through three stages known as pro-B, pre-B, and immature B cells.
B lymphocytes
43
produce cytokines that regulate a variety of T cell and antigen presenting cell functions.
B cells
43
essential for antibody production.they have a role in antigen presentation to T cells and may be necessary for optimal CD4 activation.
B lymphocytes
43
can be divided into CD4% T cells and CD+ T cells
T lymphocytes
44
mediate immune responses against intracellular pathogens
TH1 cell
44
mediate host defense against extracellular parasites, including helminths. They are also important in the induction of asthma and other allergic diseases.
TH2 cells
44
involved in the immune responses against extracellular bacteria and fungi.
TH17 cells
44
play a role in maintaining self-tolerance by regulating immune responses
Treg cells
44
capable of killing target cells by secreting granules containing granzyme and perforin or by activating apoptotic pathways in the target cell.
CD8+ effector lymphocytes
44
part of innate immunity and are capable of killing certain tumor cells and virus-infected cells without prior sensitization. Modulate the functions of other cells, including macrophages and T cells
NK lymphocytes
45
major cytokine responsible for mast cell
maturation and differentiation
KIT ligand
