Question 1

Which of the following is a useful marker for identification of platelet precursors?

Accepted Answer

A)  VWF 
B)  PF4 
C)  Phospholipase 
D)  Factor V 
A)  VWF 
B)  PF4 
C)  Phospholipase 
D)  Factor V B

Question 2

Identify the platelet receptor and plasma protein required for normal platelet aggregation. Platelet receptor Plasma protein

Accepted Answer

A)  GP IIb/IIIa Fibrinogen 
B)  GP IV Factor VIII 
C)  GP Ib/IX/V VWF 
D)  PF4 Factor V 
A)  GP IIb/IIIa Fibrinogen 
B)  GP IV Factor VIII 
C)  GP Ib/IX/V VWF 
D)  PF4 Factor V A

Question 3

From where are additional platelets first derived when the circulating count decreases?

Accepted Answer

A)  Bone marrow 
B)  Stem cells 
C)  Cells marginated on vessel endothelial cells 
D)  The 30% of mature cells stored in the spleen 
A)  Bone marrow 
B)  Stem cells 
C)  Cells marginated on vessel endothelial cells 
D)  The 30% of mature cells stored in the spleen D

Question 4

All of the following stimulate megakaryocyte and platelet production except:

Accepted Answer

A)  Interleukins 
B)  Erythropoietin 
C)  Thrombopoietin 
D)  Megakaryocyte colony-stimulating factor (Meg-CSF) 
A)  Interleukins 
B)  Erythropoietin 
C)  Thrombopoietin 
D)  Megakaryocyte colony-stimulating factor (Meg-CSF)

Question 5

Which of the following is true of thrombopoietin?

Accepted Answer

A)  Another name for erythropoietin 
B)  Promotes apoptosis of megakaryocytes 
C)  Binds to the ligand Mpl on the membrane of platelet precursors 
D)  Enhances platelet adhesion 
A)  Another name for erythropoietin 
B)  Promotes apoptosis of megakaryocytes 
C)  Binds to the ligand Mpl on the membrane of platelet precursors 
D)  Enhances platelet adhesion

Question 6

How are platelets released into peripheral circulation from the bone marrow?

Accepted Answer

A)  Mature platelets squeeze between sinusoid endothelial cells. 
B)  Megakaryocyte cytoplasmic fragments extend through the endothelial cells, lining the sinusoids, into blood and then shed platelets. 
C)  Platelets adhere to white cells and exit with them. 
D)  Megakaryocytes exit the marrow with white cells and then platelets fragment off once they reach the blood. 
A)  Mature platelets squeeze between sinusoid endothelial cells. 
B)  Megakaryocyte cytoplasmic fragments extend through the endothelial cells, lining the sinusoids, into blood and then shed platelets. 
C)  Platelets adhere to white cells and exit with them. 
D)  Megakaryocytes exit the marrow with white cells and then platelets fragment off once they reach the blood.

Question 7

A platelet histogram can be generated using automated hematology analyzers, where frequency is plotted versus platelet volume. When this histogram is examined, which of the following is true?

Accepted Answer

A)  Distribution is gaussian. 
B)  Mean platelet volume (MPV) is 14 fL. 
C)  Distribution is log normal with a small population of large platelets. 
D)  MPV is 5 fL. 
A)  Distribution is gaussian. 
B)  Mean platelet volume (MPV) is 14 fL. 
C)  Distribution is log normal with a small population of large platelets. 
D)  MPV is 5 fL.

Question 8

Phospholipids in the platelet membrane are important for all of the following functions except:

Accepted Answer

A)  Supply of arachidonic acid 
B)  Receptor for plasma fibrinogen 
C)  Receptor for plasma coagulation enzymes 
D)  Forms part of the platelet glycocalyx 
A)  Supply of arachidonic acid 
B)  Receptor for plasma fibrinogen 
C)  Receptor for plasma coagulation enzymes 
D)  Forms part of the platelet glycocalyx

Question 9

Platelet agonists are substances that:

Accepted Answer

A)  Bind to phospholipid in the platelet membrane 
B)  Promote apoptosis 
C)  Activate platelets 
D)  Enhance megakaryocyte proliferation 
A)  Bind to phospholipid in the platelet membrane 
B)  Promote apoptosis 
C)  Activate platelets 
D)  Enhance megakaryocyte proliferation

Question 10

Which of the following is true of megakaryocytes as they mature?

Accepted Answer

A)  Nucleus becomes polyploid 
B)  Cytoplasmic basophilia becomes more pronounced 
C)  Size decreases 
D)  Nucleoli become more prominent 
A)  Nucleus becomes polyploid 
B)  Cytoplasmic basophilia becomes more pronounced 
C)  Size decreases 
D)  Nucleoli become more prominent

Question 11

Identify the platelet receptor and plasma protein required for normal platelet adhesion. Platelet receptor Plasma protein

Accepted Answer

A)  Glycoprotein (GP) IV Factor VIII 
B)  Platelet factor 4 (PF4) Factor V 
C)  GP IIb/IIIa Fibrinogen 
D)  GP Ib/IX/V von Willebrand factor (VWF) 
A)  Glycoprotein (GP) IV Factor VIII 
B)  Platelet factor 4 (PF4) Factor V 
C)  GP IIb/IIIa Fibrinogen 
D)  GP Ib/IX/V von Willebrand factor (VWF)

Question 12

When platelets are activated, all of the following occur except:

Accepted Answer

A)  ($\alpha$)-Granule contents are released. 
B)  Smooth cytoplasmic membrane margins change to spiny projections. 
C)  The prostaglandin (eicosanoid synthesis) pathway is activated. 
D)  Adenosine diphosphate (ADP) release is inhibited. 
A)  ($\alpha$)-Granule contents are released. 
B)  Smooth cytoplasmic membrane margins change to spiny projections. 
C)  The prostaglandin (eicosanoid synthesis) pathway is activated. 
D)  Adenosine diphosphate (ADP) release is inhibited.

Question 13

Which of the following is not a function of the platelet surface-connected canalicular system (SCCS)?

Accepted Answer

A)  Produces energy for the cell 
B)  Delivers granule contents to the surface 
C)  Connects the internal contents to the surface 
D)  Stores plasma coagulation factors 
A)  Produces energy for the cell 
B)  Delivers granule contents to the surface 
C)  Connects the internal contents to the surface 
D)  Stores plasma coagulation factors

Question 14

What system is responsible for controlling platelet activation?

Accepted Answer

A)  Eicosanoid (prostaglandin) pathway 
B)  Surface connect canalicular system 
C)  Membrane glycoproteins 
D)  Dense tubular system 
A)  Eicosanoid (prostaglandin) pathway 
B)  Surface connect canalicular system 
C)  Membrane glycoproteins 
D)  Dense tubular system

Question 15

Platelet storage pool disorder is a deficiency of:

Accepted Answer

A)  Platelet phospholipids 
B)  ($\alpha$)-Granules 
C)  Platelet lysosomes 
D)  ($\beta$)-Granules 
A)  Platelet phospholipids 
B)  ($\alpha$)-Granules 
C)  Platelet lysosomes 
D)  ($\beta$)-Granules

Exam 13: Platelet Production, Structure, and Function

Which of the following is a useful marker for identification of platelet precursors?

Identify the platelet receptor and plasma protein required for normal platelet aggregation. Platelet receptor Plasma protein

From where are additional platelets first derived when the circulating count decreases?

All of the following stimulate megakaryocyte and platelet production except:

Which of the following is true of thrombopoietin?

How are platelets released into peripheral circulation from the bone marrow?

A platelet histogram can be generated using automated hematology analyzers, where frequency is plotted versus platelet volume. When this histogram is examined, which of the following is true?

Phospholipids in the platelet membrane are important for all of the following functions except:

Platelet agonists are substances that:

Which of the following is true of megakaryocytes as they mature?

Identify the platelet receptor and plasma protein required for normal platelet adhesion. Platelet receptor Plasma protein

When platelets are activated, all of the following occur except:

Which of the following is not a function of the platelet surface-connected canalicular system (SCCS)?

What system is responsible for controlling platelet activation?

Platelet storage pool disorder is a deficiency of:

An Overview of Clinical Laboratory Hematology

Safety in the Hematology Laboratory

Specimen Collection

Care and Use of the Microscope

Quality Assurance in Hematology and Hemostasis Testing

Cellular Structure and Function

Hematopoiesis

Erythrocyte Production and Destruction

Energy Metabolism and Membrane Physiology of the Erythrocyte

Hemoglobin Metabolism

Iron Metabolism

Leukocyte Development, Kinetics, and Functions

Routine and Point-Of-Care Testing in Hematology: Manual and Semiautomated Methods

Examination of the Peripheral Blood Film and Correlation With the Complete Blood Count

Bone Marrow Examination

Body Fluids in the Hematology Laboratory

Anemias: Red Blood Cell Morphology and Approach to Diagnosis

Disorders of Iron and Heme Metabolism

Anemias Caused by Defects of Dna Metabolism

Bone Marrow Failure

Introduction to Increased Destruction of Erythrocytes

Intrinsic Defects Leading to Increased Erythrocyte Destruction

Extrinsic Defects Leading to Increased Erythrocytedestructionnonimmune Causes

Extrinsic Defects Leading to Increased Erythrocytedestructionimmune Causes

Hemoglobinopathies Structural Defects in Hemoglobin

Thalassemias

Nonmalignant Leukocyte Disorders

Introduction to Leukocyte Neoplasms

Cytochemistry

Cytogenetics

Molecular Diagnostics in the Clinical Laboratory

Flow Cytometric Analysis in Hematologic Disorders

Myeloproliferative Neoplasms

Myelodysplastic Syndromes

Acute Leukemias

Mature Lymphoid Neoplasms

Pediatric and Geriatric Hematology

Automated Cell-Counting Instrumentation

Normal Hemostasis and Coagulation

Hemorrhagic Coagulation Disorders

Thrombosis Risk Testing

Thrombocytopenia and Thrombocytosis

Qualitative Disorders of Platelets and Vasculature

Laboratory Evaluation of Hemostasis

Monitoring Antithrombotic Therapies

Coagulation Instrumentation

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