WorksheetsHEMA2-20
Total questions: 131
Worksheet time: 1hrs 6mins
Name
Class
Date
1.
megakaryoblast
a)
MK-I
b)
MK-II
c)
MK-III
2.
least differentiated
a)
MK-I
b)
MK-II
c)
MK-III
3.
cannot be reliably distinguished from myeloblasts or pronormoblasts (light microscopy)
a)
MK-I
b)
MK-II
c)
MK-III
4.
begins to develop MOST of its cytoplasmic ultrastructure (including α-granules, dense granules, and the demarcation system (DMS))
a)
MK-I
b)
MK-II
c)
MK-III
5.
promegakaryocyte
a)
MK-I
b)
MK-II
c)
MK-III
6.
identified by the appearance of nuclear lobularity
a)
MK-I
b)
MK-II
c)
MK-III
7.
megakaryocyte
a)
MK-I
b)
MK-II
c)
MK-III
8.
most abundant
a)
MK-I
b)
MK-II
c)
MK-III
9.
easily recognized at 10X magnification (basis is size: 30 to 160 µm)
a)
MK-I
b)
MK-II
c)
MK-III
10.
At the full maturation of the cell, platelet shedding proceeds.
a)
MK-I
b)
MK-II
c)
MK-III
11.
Nucleus: Round
a)
MK-I
b)
MK-II
c)
MK-III
12.
Nucleus: Indented
a)
MK-I
b)
MK-II
c)
MK-III
13.
Nucleus: Multilobed
a)
MK-I
b)
MK-II
c)
MK-III
14.
Which of the ff. perform platelet shedding?
a)
MK-I
b)
MK-II
c)
MK-III
15.
The megakaryocyte progenitor that udnergoes endomitosis is:
a)
MK-I
b)
BFU-Meg
c)
CFU-Meg
d)
LD-CFU-Meg
16.
Nucleoli: 2 to 6
a)
MK-I
b)
MK-II
c)
MK-III
17.
Nucleoli: Variable
a)
MK-I
b)
MK-II
c)
MK-III
18.
Nucleoli: Not visible
a)
MK-I
b)
MK-II
c)
MK-III
19.
Chromatin: Deeply and variably condensed
a)
MK-I
b)
MK-II
c)
MK-III
20.
Chromatin: Moderately condensed
a)
MK-I
b)
MK-II
c)
MK-III
21.
Chromatin: Homogenous
a)
MK-I
b)
MK-II
c)
MK-III
22.
N:C ratio is 3:1
a)
MK-I
b)
MK-II
c)
MK-III
23.
N:C ratio is 1:2
a)
MK-I
b)
MK-II
c)
MK-III
24.
N:C ratio is 1:4
a)
MK-I
b)
MK-II
c)
MK-III
25.
Endomitosis is PRESENT
a)
MK-I
b)
MK-II
c)
MK-III
26.
Endomitosis ENDS here
a)
MK-I
b)
MK-II
c)
MK-III
27.
Endomitosis is ABSENT
a)
MK-I
b)
MK-II
c)
MK-III
28.
Cytoplasm: Basophilic
a)
MK-I
b)
MK-II
c)
MK-III
29.
Cytoplasm: Basophilic and granular
a)
MK-I
b)
MK-II
c)
MK-III
30.
Cytoplasm: Azurophilic and granular
a)
MK-I
b)
MK-II
c)
MK-III
31.
Mitosis in MK-I, MK-II, and MK-III
a)
Present
b)
Absent
32.
Demarcation system in MK-I, MK-II, and MK-III
a)
Present
b)
Absent
33.
One megakaryocyte may shed
a)
2000 TO 3000 plt
b)
2000 TO 4000 plt
c)
3000 TO 4000 plt
d)
4000 TO 5000 plt
34.
Which methods are used to study platelet ultrastructure?
a)
Flow cytometry
b)
Scanning and transmission electron microscopy
c)
Molecular sequencing
d)
All of the above
35.
The platelet plasma membrane is:
a)
Fully permeable
b)
Selectively permeable
c)
Impermeable
d)
Porous
36.
What does the platelet plasma membrane provide for hemostasis?
a)
Lipids for RBC membrane repair
b)
Phospholipids for platelet activation (internal) and plasma coagulation (external)
c)
Granule-release proteins
d)
Collagen-binding sites
37.
Which membrane components are anchored within the platelet membrane?
a)
Nucleic acids
b)
Lipoproteins
c)
Glycoproteins and proteoglycans
d)
Enzymes only
38.
Which phospholipids are considered neutral and found in the outer (plasma) layer of the platelet membrane?
a)
Phosphatidylserine and phosphatidylethanolamine
b)
Phosphatidylcholine and sphingomyelin
c)
Phosphatidylinositol only
d)
Cardiolipin
39.
Which type of phospholipids are found in the inner (cytoplasmic) layer of the platelet membrane?
a)
Neutral phospholipids
b)
Sterols
c)
Anionic/polar phospholipids
d)
Glycolipids
40.
Which phospholipid supplies arachidonic acid for platelet activation?
a)
Phosphatidylcholine
b)
Phosphatidylethanolamine
c)
Phosphatidylinositol
d)
Sphingomyelin
41.
Which phospholipid flips to the outer surface upon platelet activation and provides a charged surface for coagulation complex assembly?
a)
Phosphatidylcholine
b)
Phosphatidylserine
c)
Phosphatidylinositol
d)
Sphingomyelin
42.
The platelet membrane surface is known as the:
a)
Granulomere
b)
Hyalomere
c)
Glycocalyx
d)
Microtubule
43.
It is a unique ultrastructural component of platelets
a)
Granulomere
b)
Hyalomere
c)
Glycocalyx
d)
Microtubule
44.
What substances does the glycocalyx absorb from plasma via endocytosis?
a)
Hemoglobin and cytokines
b)
Albumin, fibrinogen, and other plasma proteins
c)
Nuclear fragments and complement proteins
d)
All of the above
45.
Which of the following is the key collagen receptor?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
46.
Which of the following triggers platelet activation, release of TXA2 and ADP that increase the avidity of integrins α2β1 (GP Ia/IIa) and αIIbβ3(GPIIb/IIIa)?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
47.
Bernard-Soulier syndrome is a deficiency of which of the ff?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
48.
Which of the following is the key fibrinogen receptor?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
49.
Glanzmann's thrombasthenia is a deficiency of?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
50.
Fibrinogen and VWF is the ligand of?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
51.
VWF and thrombin bind GPIbα ; thrombin cleaves a site on GP V
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
52.
Collagen is the sole ligand of?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
53.
Collagen, vitronectin, laminin, and fibronectin is the ligand of?
a)
GP Ia/IIa
b)
GP VI
c)
GP Ib/IX/V
d)
GP IIb/IIIa
54.
Thrombin is the ligand of which of the ff. receptor?
a)
PAR 1
b)
PAR 4
c)
P2Y1
d)
P2Y12
55.
When it binds, it inhibits platelet activation
a)
TPα and TPβ
b)
α2-adrenergic
c)
IP
56.
Thromboxane A2 is the ligand of which of the ff. receptor?
a)
TPα and TPβ
b)
α2-adrenergic
c)
IP
57.
Epinephrine (adrenaline) is the ligand of which of the ff. receptor?
a)
TPα and TPβ
b)
α2-adrenergic
c)
IP
58.
Prostaglandin I2 (PGI2) [aka: Prostacyclin] is the ligand of which of the ff. receptor?
a)
TPα and TPβ
b)
α2-adrenergic
c)
IP
59.
a low-affinity receptor for the immunoglobulin Fc portion (has a role in a perilous condition known as heparin-induced thrombocytopenia [HIT])
a)
FcγIIA (CD32)
b)
P-selectin (CD 62)
60.
an integrin that helps platelet binding to endothelial cells, WBCs, and one another
a)
FcγIIA (CD32)
b)
P-selectin (CD 62)
61.
found on the α-granule membranes of the resting platelet but travels via the SCCS to the surface of activated platelets
a)
FcγIIA (CD32)
b)
P-selectin (CD 62)
62.
quantification by flow cytometry is a means for measuring in vivo platelet activation
a)
FcγIIA (CD32)
b)
P-selectin (CD 62)
63.
Adenosine diphosphate is the ligand of which of the ff. receptor?
a)
PAR 1
b)
PAR 4
c)
P2Y1
d)
P2Y12
64.
Which of the following move INWARD on activation to enable expression of alpha granule contents?
a)
Microtubules
b)
Microfilaments
65.
During platelet shape change, ___ also reassemble in long parallel bundles to provide rigidity to pseudopods.
a)
Microtubules
b)
Microfilaments
66.
Which platelet cytoskeletal component is formed by tubulins and maintains the platelet’s discoid shape?
a)
Microtubules
b)
Microfilaments
67.
Where do platelet microtubules lie within the cell?
a)
Deep cytoplasm
b)
Inside organelles
c)
Just within, but not touching, the plasma membrane
d)
Transmembrane channels
68.
What happens to platelet shape when microtubules disassemble due to cold exposure?
a)
They form pseudopods
b)
Platelets become round
c)
Dense granules rupture
d)
Platelets lyse
69.
Which protein forms platelet microfilaments?
a)
Tubulin
b)
Keratin
c)
Actin
d)
Collagen
70.
What triggers the conversion of actin from globular to filamentous form?
a)
ATP depletion
b)
Decreased cytoplasmic calcium
c)
Increased cytoplasmic calcium
d)
Presence of fibrinogen
71.
Which intermediate filaments help maintain platelet shape by connecting with actin and microtubules?
a)
Keratin and elastin
b)
Desmin and vimentin
c)
Myosin and dynein
d)
Lamin and fibrillin
72.
How many alpha granules does a platelet typically contain?
a)
5 to 10
b)
15 to 30
c)
50 to 80
d)
100 to 120
73.
Which granules release their contents through the SCCS after activation?
a)
Alpha granules and dense granules only
b)
Dense granules and lysosomes only
c)
Alpha granules and lysosomes only
d)
All of the above
74.
What color do alpha granules stain in osmium-stained TEM preparations?
a)
Dark yellow
b)
Light gray
c)
Medium gray
d)
Light yellow
75.
Which of the following is NOT a role of alpha granule contents?
a)
Supporting plasma coagulation
b)
Participating in platelet adhesion
c)
Participating in platelet aggregation
d)
Providing energy for oxidative phosphorylation
76.
How many dense granules does each platelet typically contain?
a)
1 to 2
b)
2 to 7
c)
4 to 6
d)
10 to 15
77.
What is another term for dense granules?
a)
Alpha granules
b)
Delta granules
c)
Beta granules
d)
All of the above
78.
How do dense granules appear when stained with osmium in TEM?
a)
Medium gray
b)
Transparent
c)
Light yellow
d)
Black and opaque
79.
. Where do dense granules release their contents during platelet activation?
a)
Open canalicular system
b)
Directly into the plasma
c)
Directly into the cytoskeleton
d)
Directly into the mitochondria
80.
What type of substances do dense granules primarily contain?
a)
Coagulation factors
b)
Growth factors only
c)
Vasoconstrictors and platelet agonists
d)
Plasma proteins
81.
What is the meaning of “agonist” in platelet physiology?
a)
A substance that inhibits receptor activity
b)
A substance that damages platelet membranes
c)
A substance that initiates a response upon receptor binding
d)
A substance that dissolves fibrin
82.
Supports neighboring platelet aggregation by binding to P2Y1 and P2Y12
a)
ADP
b)
ATP
c)
Phosphate
d)
Serotonin
83.
Function unknown, but ATP release is detectable upon platelet activation
a)
ADP
b)
ATP
c)
Phosphate
d)
Serotonin
84.
Vasoconstrictor that binds endothelial cells and platelet membranes
a)
ADP
b)
ATP
c)
Phosphate
d)
Serotonin
85.
Divalent cations support platelet activation and coagulation
a)
Histamine
b)
Ca2+ and Mg2+
c)
Epinephrine
86.
✓ Few in number
✓ Stain positive for arylsulfatase, β-glucuronidase, acid phosphatase, and catalase
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
87.
contents flow through the SCCS.
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
88.
probably digest vessel wall matrix components during in vivo aggregation and may also digest autophagic debris
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
89.
The plasma membrane invades platelet interior, producing
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
90.
✓ Glycocalyx is less developed in the ___ and lacks some of the glycoprotein receptors present on the platelet surface.
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
91.
the route for:
o endocytosis
o secretion of α-granule contents
o secretion of lysosome contents
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
92.
Control center for platelet activation
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
93.
Parallel and closely aligned to the SCCS
✓ a condensed remnant of the rough endoplasmic reticulum
✓ sequesters calcium and bears a series of enzymes that support platelet activation
a)
Alpha granules
b)
Lysosomes
c)
Surface-Connected-Canalicular System (SCCS)
d)
Dense Tubular System (DTS)
94.
support the eicosanoid synthesis pathway that produces thromboxane A2
a)
phospholipase A2, cyclooxygenase, and thromboxane synthetase
b)
phospholipase C
95.
(supports production of inositol triphosphate (IP3) and diacylglycerol (DAG)
a)
phospholipase A2, cyclooxygenase, and thromboxane synthetase
b)
phospholipase C
96.
◦β-thromboglobulin
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
97.
◦PF-4 (platelet factor-4)
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
98.
◦HMWK
◦PAI-1 (plasminogen activator inhibitor-1)
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
99.
Plasminogen, Protein C inhibitor
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
100.
◦EGF (endothelial growth factor)
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
101.
TGF-β (transforming growth factor-β)
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
102.
Fibrinogen
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
103.
◦Fibronectin ◦Albumin
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
104.
◦Thrombospondin ◦Factor V
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
105.
◦P-selectin
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
106.
◦GP IIb/IIIa ◦GP IV ◦GP Ib/IX/V
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
107.
inhibit heparin
a)
β-thromboglobulin
b)
PF-4 (platelet factor-4)
c)
EGF
d)
PDGF
e)
TGF-B
108.
support mitosis of vascular fibroblasts and smooth muscle cells
a)
β-thromboglobulin
b)
PF-4 (platelet factor-4)
c)
EGF
d)
PDGF
e)
TGF-B
109.
Aspirin ingestion blocks the synthesis of:
a)
a. Thromboxane A2
b)
b. Ionized calcium
c)
c. Collagen
d)
d. ADP
110.
◦Immunoglobulins ◦VWF
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
111.
◦PDGF (platelet-derived growth factor)
a)
α-granules (but not in the cytoplasm)
b)
α-granules and platelet cytoplasm
c)
α-granule membrane
d)
α-granule membrane and plasma membrane
112.
To perform plt count, what dilution should be used?
a)
1:10
b)
1:100
c)
1:20
d)
1:200
113.
What is the general normal range for platelet count?
a)
50–100 × 10⁹/L
b)
150–450 × 10⁹/L
c)
450–700 × 10⁹/L
d)
100 × 10⁹/L
114.
A platelet count below which level is the most common cause of clinically important bleeding?
a)
50–100 × 10⁹/L
b)
150–450 × 10⁹/L
c)
450–700 × 10⁹/L
d)
100 × 10⁹/L
115.
Which method is considered the reference method for platelet counting?
a)
Automated impedance counter
b)
Turbidimetric method
c)
Brecher and Cronkite phase-contrast method
d)
Manual direct count with crystal violet stain
116.
What reagent is used for platelet counting?
a)
3% acetic acid
b)
1% ammonium oxalate
c)
10% ammonium oxalate
d)
NSS (0.85% NaCl)
117.
Which cells are lysed by 1% ammonium oxalate in the platelet count procedure?
a)
Platelets
b)
Leukocytes
c)
Non-nucleated RBCs
d)
Nucleated RBCs
118.
Platelets are counted in which area of the hemocytometer?
a)
25 small squares of the central large square
b)
25 small squares of the central small square
c)
Either
d)
Neither
119.
Which objective lens is used to count platelets in the phase-contrast method?
a)
4x
b)
10x
c)
40x
d)
100x
120.
Store the hemocytometer in a moist chamber for how long to allow platelet settling?
a)
5 minutes
b)
10 minutes
c)
15 minutes
d)
30 minutes
121.
Which of the following describes platelets under a phase-contrast microscope?
a)
7–10 µm, bright pink
b)
2–4 µm, round/oval, light purple sheen
c)
1 µm, bright green refractile
d)
Irregular, red-orange
122.
What is the acceptable difference between total platelet counts on both sides of a hemocytometer?
a)
<5%
b)
<10%
c)
<15%
d)
<20%
123.
In plt count estimation, a normal (wedge) blood smear should demonstrate approximately
a)
7 to 21 cells per 10x field
b)
7 to 21 cells per 100x field
c)
Either
d)
Neither
124.
PLATELET ESTIMATE OF: 0 to 49,000/uL
a)
Marked decrease
b)
Moderate decrease
c)
Slight decrease
d)
Low normal
125.
PLATELET ESTIMATE OF: 50,000 to 99,000/uL
a)
Marked decrease
b)
Moderate decrease
c)
Slight decrease
d)
Low normal
126.
PLATELET ESTIMATE OF: 100,000 to 149,000/uL
a)
Marked decrease
b)
Moderate decrease
c)
Slight decrease
d)
Low normal
127.
PLATELET ESTIMATE OF: 150,000 to 199,000/uL
a)
Marked decrease
b)
Moderate decrease
c)
Slight decrease
d)
Low normal
128.
PLATELET ESTIMATE OF: 200,000 to 400,000/uL
a)
Normal
b)
Slight increase
c)
Moderate increase
d)
Marked increase
129.
PLATELET ESTIMATE OF: 401,000 to 599,000/uL
a)
Normal
b)
Slight increase
c)
Moderate increase
d)
Marked increase
130.
PLATELET ESTIMATE OF: 600,000 to 800,000/uL
a)
Normal
b)
Slight increase
c)
Moderate increase
d)
Marked increase
131.
PLATELET ESTIMATE OF: Above 800,000/uL
a)
Normal
b)
Slight increase
c)
Moderate increase
d)
Marked increase
100 %
