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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
Q

These are largely composed of platelets and won Willebrand factor

A

White clots

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25
Q

Upon activation, platelets secrete alpha-granules contents via what?

A

SCCS

Surface-Connected Canalicular System

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26
Q

These bud off of platelets after their exposure to strong agonists

A

Microparticles

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27
Q

Megakaryocytes cluster with hematopoietic stem cells in vascular niches under the influence of what?

A

under the influence of an array of stromal cell cytokines

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28
Q

Megakaryocytes cluster with hematopoietic stem cells in vascular niches adjacent to what?

A

Adjacent to venous sinusoid endothelial cells

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29
Q

Reponding to the growth factor TPO, megakaryocyte progenitors are recruited from what?

A

Common myeloid progenitors

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30
Q

Megakaryocyte progenitors are recruited from common myeloid progenitors in response to what growth factor?

A

TPO

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31
Q

Megakaryocytes are also found in the lungs

True or False

A

TRUE

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32
Q

Megakaryocyte progenitors arise from common myeloid progenitors

True or False

A

True

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33
Q

Megakaryocyte progenitors arise from common myeloid progenitors under the influence of what transcription gene product?

A

GATA-1

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34
Q

What does the abbreviation GATA-1 mean?

A

“globin transcription factor-1”

35
Q

GATA-1 is regulated by what cofactor?

FOGI

36
Q

What does the abbreviation FOG1 mean?

A

“friend of GATA”

37
Q

It is a protein product of the X chromosome gene GATA1

38
Q

It is a product of the ZFPM1 gene?

39
Q

What does the abbreviation ZFPM1 mean?

A

“zinc finger protein multitype 1”

40
Q

Megakaryocyte differentiation is supressed by another transcription gene product called?

41
Q

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.

A

GATA-1 and MYB

42
Q

GATA-1 and MYB act in opposition to balance megakaryocytopoiesis with erythropoiesis, where the same progenitor cell is differentiated into what?

A

Platelet cell line and red blood cell line

43
Q

Three megakaryocyte lineage-committed progenitor stages, defined by their in vivo culture colony characteristics, arise from the common myeloid progenitor.

True or False

A

FALSE

“… by their IN VITRO culture colony…”

44
Q

What the order of differentiation of the three megakaryocyte lineage-committed progenitor stages?

A
  1. BFU-Meg
  2. CFU-Meg
  3. LD-CFU-Meg
45
Q

In the order of differentiation of the three megakaryocyte lineage-committed progenitor stages, which is the least mature?

A

BFU-Meg

Burst-forming Unit

46
Q

In the order of differentiation of the three megakaryocyte lineage-committed progenitor stages, which is the intermediate one?

A

CFU-Meg

Colony-forming Unit

47
Q

These two are diploid and undergo normal mitosis to maintain a viable pool of megakaryocyte progenitors

A

BFU-Meg and CFU-Meg

48
Q

All three progenitor stages resemble what?

A

lymphocytes

49
Q

All three progenitor stages resemble lymphocytes and can be distinguished by Wright-stained light microscopy

True of False

A

FALSE

caanot be distinguished by Wright-stained light microscopy

50
Q

All three progenitor stages resemble lymphocytes and can be distinguished by Wright-stained light microscopy

True of False

A

FALSE

caanot be distinguished by Wright-stained light microscopy

51
Q

Why must BFU-Meg and CFU-Meg undergo normal mitosis?

A

to maintain a viable pool of megakaryocyte progenitors

52
Q

What is the proliferative property of BFU-Megs?

A

they have the ability to form hundreds of BFU-Meg colonies in culture

53
Q

What is the proliferative property of CFU-Megs?

A

they have the ability to form dozens of CFU-Meg colonies in culture

54
Q

Among the three progenitor stages, which is the only one that undergoes enndomitosis?

A

LD-CFU-Meg

55
Q

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.

A

Endomitosis

56
Q

In endomitosis, this is a form of mitosis that lacks what?

A

lacks telophase and cytokinesis

57
Q

this is the phase of separation into daughter cells

A

Cytokinesis

58
Q

As GATA-1 and FOG1-driven transcription accelerates, another transcription factor, called NF-E2, mediates the switch from mitosis to endomitosis.

True or False

A

FALSE

As GATA-1 and FOG1-driven transcription slows; RUNX1

59
Q

This is another transcription factor that mediates the switch from mitosis to endomitosis

60
Q

The RUNX1 trancription factor mediates the switch from mitosis to endomitosis by suppressing what signaling pathway?

A

By suppressing the Rho/ROCK signaling pathway

61
Q

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

A

inadequate levels of actin and myosin

62
Q

These are muscle fiber-like molecules

63
Q

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?

A

Under the influence of transcription factor NF-E2

64
Q

Megakarblasts do not resemble lymphocytes

True or False

A

True

only BFU, CFU, and LD-CFU resemble lymphocytes

65
Q

When megakaryocytes reach 128N, this level of ploidy is unusual and may signal what?

A

hematologic disease

66
Q

What is MK-1?

A

megakaryoblast

67
Q

MK-1 resembles what?

A

resembles the myeloblast and pronormoblast

68
Q

Pronormoblasts are also called…

A

rubriblasts

69
Q

The promegakaryocyte has cytoplasmic “blebs”

True or False

A

False

megakaryoblasts have cytoplasmic “blebs”

70
Q

The promegakaryocyte has cytoplasmic “blebs”

True or False

A

False

megakaryoblasts have cytoplasmic “blebs”

71
Q

These cytoplasmic “blebs” resemble what?

A

They resemble platelets

72
Q

What is MK-II?

A

Promegakaryocyte

73
Q

In promegakaryocytes, cytoplasm is abundant, and the nucleus has minimal lobularity

True or False

74
Q

What is MK-III?

A

Megakaryocyte

75
Q

The cytoplasm of a megakaryocyte is … and with evidence of what?

A

azurophilic and granular… and with evidence of DMS

demarcation system

76
Q

When megakaryocyte progenitors leave the proliferative phase, they enter into what?

A

Terminal differentiation

77
Q

This is a series of stages in which microscopists become able to recognize their unique Wright-stained morphology in bone marrow aspirate films

A

Terminal differentiation

78
Q

Bone marrow aspirate is also known as

A

hematoxylin and eosin-stained bone marrow biopsy section

79
Q

What is the least differentiated megakaryocyte precursor, according to morphologists?

A

MK-I stage or megakaryoblasts

80
Q

What is the characteristic of the nucleus of MK-III?

A

Multilobed

81
Q

What is the N:C ratio of MK-III?

82
Q

Mitosis is absent in MK-I, MK-II, and MK-III

True or False

83
Q

Endomitosis is present in MK-I, MK-II, and MK-III

True or False

A

False

Endomitosis is present in MK-I; Ends in MK-II; Absent in MK-III

84
Q

Cytoplasm is basophilic in MK-I, MK-II, and MK-III

True or False

A

False

Cytoplasm is azurophilic and granular in MK-III

85
Q

Cytoplasm is basophilic and granular in MK-II only

True or False

HEMATOLOGY 2 - LECTURE (9 decks)

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