Success- Hemostasis Questions and Answers 2023 Graded
A+
1) The hemorrhagic problems associated with scurvy are due to a deficiency of
_________, which is a cofactor required for collagen synthesis.
A. Vitamin C
B. Prothrombin
C. Vitmain K
D. Protein C
A. Vitamin C
2) The number of platelets an average megakaryocyte generates is
approximately:
A. 25-50
B. 50-200
C. 200-500
D. 2000-4000
D. 2000-4000
3) Which of the following is not a cause of thrombocytopenia?
A. Splenomegaly
B. Chemotherapy
C. Increased thrombopoietin
D. Aplastic anemia
C. Increased thrombopoietin
4) Platelets interacting with and binding to other platelets is referred to as:
A. Adhesion
B. Aggregation
C. Release
D. Retration
B. Aggregation
5) In a platelet aggregation studies, certain aggregating agents induce a biphasic
aggregation curve. This second phase of aggregation is directly related to:
A. Formation of fibrin
B. Changes in platelet shape
C. Release of endogenous ADP
D. Release of platelet factor 3
C. Release of endogenous ADP
6) A platelet aggregation agent that characteristically yields a biphasic curve
when used in optimal concentration is:
A. Arachidonic acid
B. Collagen
C. Epinephrine
D. Ristocetin
C. Epinephrine
,Epinephrine is the only aggregating agent listed that typically gives a biphasic pattern.
ADP and thrombin also give biphasic patterns when used in optimal concentration.
7) The platelet aggregation pattern (after addition, a slight drop and then curved
increase to plateau) is characteristic of the aggregating agent:
A. ADP
B. Collagen
C. Ristocetin
D. Thrombin
B. Collagen
Collagen is the only aggregating agent that includes a single wave response preceded
by a lag phase. During the lag phase collagen stimulates platelets to release their
granule contents. Endogenous ADP released from the platelets then initiates
irreversible platelet aggregation.
8) The operating principle of a platelet aggregometer is best described as:
A. Aggregation on a foreign surface: platelet aggregation is directly proportional
to the difference in platelet counts performed before and after platelet-rich
plasma is passed through a column of glass beads
B. Change in optical density: as platelets aggregate, the optical density of the
platelet-rich plasma decreases.
C. Electrical impedance: platelet aggregates are counted as they pass through an
aperture, temporarily interrupting the of current between two electrodes.
D. Pulse editing: editing electronically generated pulses can differentiate the
number of free platelets versus platelet aggregates
B. Change in optical density: as platelets aggregate, the optical density of the platelet-
rich plasma decreases.
9) Of the following therapeutic agents, those considered to be antiplatelet
medications are:
A. Aspirin and Plavix
B. Coumadin and heparin
C. Heparine and protamine sulfate
D. Tissue plasminogen activator and streptokinase
A. Aspirin and Plavix
10) A potent inhibitor of platelet aggregation released by endothelial cells is:
A. Epinephrine
B. Prostacyclin
C. Ristocetin
D. Thromboxane A2
B. Prostacyclin
11) The reference value for mean platelet volume (MPV) is approximately:
A. 2-4 fL
B. 5-7 fL
C. 8-10 fL
D. 11-14 fL
C. 8-10 fL
, 12) The platelet parameter PDW refers to the:
A. Average platelet volume
B. Cell weight versus density
C. Capacity to adhere to foreign surfaces
D. Variation in platelet cell size
D. Variation in platelet cell size
13) A normal histogram showing platelet size distribution is best described as:
A. Bimodal, nonskewed peaks
B. Left-skewed single peak
C. Right-skewed single peak
D. Single peak, gaussian distribution
C. Right-skewed single peak
14) Which of the following is not a normal maturation stage for platelets?
A. Megakaryoblast
B. Promegakaryocyte
C. Micromegakaryocyte
D. Megakaryocyte
C. Micromegakaryocyte
15) The recommended type of microscopy for the performance of manual platelet
counts is:
A. Electron
B. Dark field
C. Light
D. Phase Contrast
D. Phase Contrast
16) Twenty microliters of blood are diluted in 1.98 mL of diluent. This dilution is
plated on both sides of a Neubauer-ruled counting chamber. A total of 356 cells is
seen when both large center squares are counted. The platelet count expressed
in SI units is:
A. 178 x 10^9/L
B.178 x10^3/uL
C. 356 x10^9/L
D. 712 x10^9/L
A. 178 X 109/L
Dilution is 1:100 therefore dilution factor is 100.
Formula is: [total number cells counted X dilution factor]/ [total area counted X depth]
[356 X 100]/ [2 X 0.10]= 178,000= 178 x 103/mm3; when expressed in SI units, the
platelet count is 178 X 109/L
17) The size threshold range used by electrical impedance methods to count
particles as platelets is:
A. 0-10 fL
B. 2-20 fL
C. 15-40 fL
D. 35-90 fL
B. 2-20 fL
A+
1) The hemorrhagic problems associated with scurvy are due to a deficiency of
_________, which is a cofactor required for collagen synthesis.
A. Vitamin C
B. Prothrombin
C. Vitmain K
D. Protein C
A. Vitamin C
2) The number of platelets an average megakaryocyte generates is
approximately:
A. 25-50
B. 50-200
C. 200-500
D. 2000-4000
D. 2000-4000
3) Which of the following is not a cause of thrombocytopenia?
A. Splenomegaly
B. Chemotherapy
C. Increased thrombopoietin
D. Aplastic anemia
C. Increased thrombopoietin
4) Platelets interacting with and binding to other platelets is referred to as:
A. Adhesion
B. Aggregation
C. Release
D. Retration
B. Aggregation
5) In a platelet aggregation studies, certain aggregating agents induce a biphasic
aggregation curve. This second phase of aggregation is directly related to:
A. Formation of fibrin
B. Changes in platelet shape
C. Release of endogenous ADP
D. Release of platelet factor 3
C. Release of endogenous ADP
6) A platelet aggregation agent that characteristically yields a biphasic curve
when used in optimal concentration is:
A. Arachidonic acid
B. Collagen
C. Epinephrine
D. Ristocetin
C. Epinephrine
,Epinephrine is the only aggregating agent listed that typically gives a biphasic pattern.
ADP and thrombin also give biphasic patterns when used in optimal concentration.
7) The platelet aggregation pattern (after addition, a slight drop and then curved
increase to plateau) is characteristic of the aggregating agent:
A. ADP
B. Collagen
C. Ristocetin
D. Thrombin
B. Collagen
Collagen is the only aggregating agent that includes a single wave response preceded
by a lag phase. During the lag phase collagen stimulates platelets to release their
granule contents. Endogenous ADP released from the platelets then initiates
irreversible platelet aggregation.
8) The operating principle of a platelet aggregometer is best described as:
A. Aggregation on a foreign surface: platelet aggregation is directly proportional
to the difference in platelet counts performed before and after platelet-rich
plasma is passed through a column of glass beads
B. Change in optical density: as platelets aggregate, the optical density of the
platelet-rich plasma decreases.
C. Electrical impedance: platelet aggregates are counted as they pass through an
aperture, temporarily interrupting the of current between two electrodes.
D. Pulse editing: editing electronically generated pulses can differentiate the
number of free platelets versus platelet aggregates
B. Change in optical density: as platelets aggregate, the optical density of the platelet-
rich plasma decreases.
9) Of the following therapeutic agents, those considered to be antiplatelet
medications are:
A. Aspirin and Plavix
B. Coumadin and heparin
C. Heparine and protamine sulfate
D. Tissue plasminogen activator and streptokinase
A. Aspirin and Plavix
10) A potent inhibitor of platelet aggregation released by endothelial cells is:
A. Epinephrine
B. Prostacyclin
C. Ristocetin
D. Thromboxane A2
B. Prostacyclin
11) The reference value for mean platelet volume (MPV) is approximately:
A. 2-4 fL
B. 5-7 fL
C. 8-10 fL
D. 11-14 fL
C. 8-10 fL
, 12) The platelet parameter PDW refers to the:
A. Average platelet volume
B. Cell weight versus density
C. Capacity to adhere to foreign surfaces
D. Variation in platelet cell size
D. Variation in platelet cell size
13) A normal histogram showing platelet size distribution is best described as:
A. Bimodal, nonskewed peaks
B. Left-skewed single peak
C. Right-skewed single peak
D. Single peak, gaussian distribution
C. Right-skewed single peak
14) Which of the following is not a normal maturation stage for platelets?
A. Megakaryoblast
B. Promegakaryocyte
C. Micromegakaryocyte
D. Megakaryocyte
C. Micromegakaryocyte
15) The recommended type of microscopy for the performance of manual platelet
counts is:
A. Electron
B. Dark field
C. Light
D. Phase Contrast
D. Phase Contrast
16) Twenty microliters of blood are diluted in 1.98 mL of diluent. This dilution is
plated on both sides of a Neubauer-ruled counting chamber. A total of 356 cells is
seen when both large center squares are counted. The platelet count expressed
in SI units is:
A. 178 x 10^9/L
B.178 x10^3/uL
C. 356 x10^9/L
D. 712 x10^9/L
A. 178 X 109/L
Dilution is 1:100 therefore dilution factor is 100.
Formula is: [total number cells counted X dilution factor]/ [total area counted X depth]
[356 X 100]/ [2 X 0.10]= 178,000= 178 x 103/mm3; when expressed in SI units, the
platelet count is 178 X 109/L
17) The size threshold range used by electrical impedance methods to count
particles as platelets is:
A. 0-10 fL
B. 2-20 fL
C. 15-40 fL
D. 35-90 fL
B. 2-20 fL
