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HEMATOLOGY 2 - LECTURE > CHAPTER 10: Platelet Production, Structure, and Function > Flashcards

CHAPTER 10: Platelet Production, Structure, and Function Flashcards

1
Q

These are nonnucleated blood cells that circulate at a concentration of 150 to 400 x 10^9/L

A

platelets

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2
Q

The average platelet counts
slightly higher in women than in men

True or False

A

True

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3
Q

Platelet count is slightly higher in
members of both sexes who are older than 80 years

True or False

A

False

slightly lower; 65 years

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4
Q

At what concentration do platelets circulate at?

A

150 to 400 x 10^9/L

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5
Q

They trigger primary hemostasis on exposure to subendothelial
collagen or endothelial cell inflammatory proteins at the time
of blood vessel injury

A

Platelets

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6
Q

Platelets trigger what kind of hemostasis?

A

Primary hemostasis

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7
Q

They trigger primary hemostasis on exposure to what?

A

On exposure to subendothelial collagen or endothelial cell inflammatory proteins

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8
Q

When do platelets trigger primary hemostasis?

A

At the time of blood vessel injury

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9
Q

Platelets arise from unique bone marrow cells called …

A

Megakaryocytes

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10
Q

These are the largest cells in the bone marrow

A

Megakaryocytes

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11
Q

Megakaryocytes possess multiple chromosome copies called …

A

Polyploid

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12
Q

On Wright-stained bone marrow aspirate smear, what do megakaryocytes look like?

A
  • 30 to 50 mm in diameter
  • multilobulated nucleus
  • abundant granular cytoplasm
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13
Q

Megakaryocytes account for how many of all bone marrow cells?

A

Less than 0.5% of all bone marrow cells

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14
Q

On a Wright-stained bone marrow aspirate smear megakaryocytes account for how many pero 10x low-power field?

A

2 to 4 megakaryocytes

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15
Q

The megakaryocyte progenitor that undergoes endomitosis

A

LD-CFU-Meg

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16
Q

The growth factor that is produced in the kidney and induces growth and differentiation of committed megakaryocyte progenitors is …

A

Thrombopoietin

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17
Q

What platelet organelle sequesters ionic calcium and binds a series of enzymes of the eicosanoid pathway?

A

DTS

Dense Tubular System

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18
Q

What platelet membrane receptor binds fibrinogen and supports platelet aggregation?

A

GP IIb/IIIa

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19
Q

What platelet membrane phospholipid flips from the inner surface to the plasma surface on activation and serves as the assembly point for coagulation factors?

A

Phosphatidylserine

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20
Q

What is the name of the eicosanoid metabolite produced from the endothelial cells that suppresses platelet activity?

A

Prostacyclin

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21
Q

What molecule is stored in platelet dense granules?

A

Serotonin

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22
Q

What plasma protein is essential for platelet adhesion?

A

vWF

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23
Q

Reticulated platelets can be enumerated in peripheral blood to detect decreased platelet production in response to need

True or False

A

FALSE

increased platelet production in response to need

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23
Q

Reticulated platelets can be enumerated in peripheral blood to detect decreased platelet production in response to need

True or False

A

FALSE

increased platelet production in response to need

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24
These are largely composed of platelets and won Willebrand factor
White clots
25
Upon activation, platelets secrete alpha-granules contents via what?
SCCS | Surface-Connected Canalicular System
26
These bud off of platelets after their exposure to strong agonists
Microparticles
27
Megakaryocytes cluster with hematopoietic stem cells in vascular niches under the influence of what?
under the influence of an array of stromal cell cytokines
28
Megakaryocytes cluster with hematopoietic stem cells in vascular niches adjacent to what?
Adjacent to venous sinusoid endothelial cells
29
Reponding to the growth factor TPO, megakaryocyte progenitors are recruited from what?
Common myeloid progenitors
30
Megakaryocyte progenitors are recruited from common myeloid progenitors in response to what growth factor?
TPO
31
Megakaryocytes are also found in the lungs | True or False
TRUE
32
Megakaryocyte progenitors arise from common myeloid progenitors | True or False
True
33
Megakaryocyte progenitors arise from common myeloid progenitors under the influence of what transcription gene product?
GATA-1
34
What does the abbreviation GATA-1 mean?
"globin transcription factor-1"
35
GATA-1 is regulated by what cofactor? ## Footnote FOGI
FOG1
36
What does the abbreviation FOG1 mean?
"friend of GATA"
37
It is a protein product of the X chromosome gene GATA1
GATA-1
38
It is a product of the ZFPM1 gene?
FOG1
39
What does the abbreviation ZFPM1 mean?
"zinc finger protein multitype 1"
40
Megakaryocyte differentiation is supressed by another transcription gene product called?
MYB gene
41
These two act in opposition to balance megakaryocytopoiesis with erythropoiesis, where the same progenitor cell is differentiated into the platelet cell line and red blood cell line.
GATA-1 and MYB
42
GATA-1 and MYB act in opposition to balance megakaryocytopoiesis with erythropoiesis, where the same progenitor cell is differentiated into what?
Platelet cell line and red blood cell line
43
Three megakaryocyte lineage-committed progenitor stages, defined by their in vivo culture colony characteristics, arise from the common myeloid progenitor. | True or False
FALSE | "... by their IN VITRO culture colony..."
44
What the order of differentiation of the three megakaryocyte lineage-committed progenitor stages?
1. BFU-Meg 2. CFU-Meg 3. LD-CFU-Meg
45
In the order of differentiation of the three megakaryocyte lineage-committed progenitor stages, which is the least mature?
BFU-Meg | Burst-forming Unit
46
In the order of differentiation of the three megakaryocyte lineage-committed progenitor stages, which is the intermediate one?
CFU-Meg | Colony-forming Unit
47
These two are diploid and undergo normal mitosis to maintain a viable pool of megakaryocyte progenitors
BFU-Meg and CFU-Meg
48
All three progenitor stages resemble what?
lymphocytes
49
All three progenitor stages resemble lymphocytes and can be distinguished by Wright-stained light microscopy | True of False
FALSE | caanot be distinguished by Wright-stained light microscopy
50
All three progenitor stages resemble lymphocytes and can be distinguished by Wright-stained light microscopy | True of False
FALSE | caanot be distinguished by Wright-stained light microscopy
51
Why must BFU-Meg and CFU-Meg undergo normal mitosis?
to maintain a viable pool of megakaryocyte progenitors
52
What is the proliferative property of BFU-Megs?
they have the ability to form hundreds of BFU-Meg colonies in culture
53
What is the proliferative property of CFU-Megs?
they have the ability to form dozens of CFU-Meg colonies in culture
54
Among the three progenitor stages, which is the only one that undergoes enndomitosis?
LD-CFU-Meg
55
This is a partially characterized form of mitosis unique to megakaryocytes in which DNA replication and cytoplasmic maturation are normal but cell lose their capacity to divide.
Endomitosis
56
In endomitosis, this is a form of mitosis that lacks what?
lacks telophase and cytokinesis
57
this is the phase of separation into daughter cells
Cytokinesis
58
As GATA-1 and FOG1-driven transcription accelerates, another transcription factor, called NF-E2, mediates the switch from mitosis to endomitosis. | True or False
FALSE | As GATA-1 and FOG1-driven transcription slows; RUNX1
59
This is another transcription factor that mediates the switch from mitosis to endomitosis
RUNX1
60
The RUNX1 trancription factor mediates the switch from mitosis to endomitosis by suppressing what signaling pathway?
By suppressing the Rho/ROCK signaling pathway
61
In response to the reduced Rho/ROCK signal, inadequate levels of what and what assemble in the cytoplasmic constrictions where separatio would otherwise occur, preventing cytokinesis | "otherwise" kasi walang cell membrane separation in endomitosis
inadequate levels of actin and myosin
62
These are muscle fiber-like molecules
myosin
63
Under the influence of what transcription factor does DNA replication proceeds to the production of 8N, 16N, or even 32N ploidy with duplicated chromosome sets?
Under the influence of transcription factor NF-E2
64
Megakarblasts do not resemble lymphocytes | True or False
True | only BFU, CFU, and LD-CFU resemble lymphocytes
65
When megakaryocytes reach 128N, this level of ploidy is unusual and may signal what?
hematologic disease
66
What is MK-1?
megakaryoblast
67
MK-1 resembles what?
resembles the myeloblast and pronormoblast
68
Pronormoblasts are also called...
rubriblasts
69
The promegakaryocyte has cytoplasmic "blebs" | True or False
False | megakaryoblasts have cytoplasmic "blebs"
70
The promegakaryocyte has cytoplasmic "blebs" | True or False
False | megakaryoblasts have cytoplasmic "blebs"
71
These cytoplasmic "blebs" resemble what?
They resemble platelets
72
What is MK-II?
Promegakaryocyte
73
In promegakaryocytes, cytoplasm is abundant, and the nucleus has minimal lobularity | True or False
True
74
What is MK-III?
Megakaryocyte
75
The cytoplasm of a megakaryocyte is ... and with evidence of what?
azurophilic and granular... and with evidence of DMS | demarcation system
76
When megakaryocyte progenitors leave the proliferative phase, they enter into what?
Terminal differentiation
77
This is a series of stages in which microscopists become able to recognize their unique Wright-stained morphology in bone marrow aspirate films
Terminal differentiation
78
Bone marrow aspirate is also known as
hematoxylin and eosin-stained bone marrow biopsy section
79
What is the least differentiated megakaryocyte precursor, according to morphologists?
MK-I stage or megakaryoblasts
80
What is the characteristic of the nucleus of MK-III?
Multilobed
81
What is the N:C ratio of MK-III?
1:4
82
Mitosis is absent in MK-I, MK-II, and MK-III | True or False
True
83
Endomitosis is present in MK-I, MK-II, and MK-III | True or False
False | Endomitosis is present in MK-I; Ends in MK-II; Absent in MK-III
84
Cytoplasm is basophilic in MK-I, MK-II, and MK-III | True or False
False | Cytoplasm is azurophilic and granular in MK-III
85
Cytoplasm is basophilic and granular in MK-II only | True or False
TRUE

HEMATOLOGY 2 - LECTURE (9 decks)

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