HEMA 2 QUIZ 1 Flashcards
Thrombotic thrombocytopenic purpura (TTP) is characterized by:
A. Prolonged PT
B. Increased platelet aggregation
C. Thrombocytosis
D. Prolonged APTT
Increased platelet aggregation
Thrombocytopenia may be associated with:
A. Postsplenectomy
B. Hypersplenism
C. Acute blood loss
D. Increased proliferation of pluripotential stem cells
Hypersplenism
Aspirin prevents platelet aggregation by inhibiting the action of which enzyme?
A. Phospholipase
B. Cyclo-oxygenase
C. Thromboxane A2 synthetase
D. Prostacyclin synthetase
Cyclo-oxygenase
Normal platelet adhesion depends upon:
A. Fibrinogen
B. Glycoprotein Ib
C. Glycoprotein IIb, IIIa complex
D. Calcium
Glycoprotein Ib
Which of the following test results is normal in a patient with classic von Willebrand’s disease?
A. Bleeding time
B. Activated partial thromboplastin time
C. Platelet count
D. Factor VIII:C and von Willebrand’s factor (VWF) levels
Platelet count
Bernard–Soulier syndrome is associated with:
A. Decreased bleeding time
B. Decreased factor VIII assay
C. Thrombocytopenia and giant platelets
D. Abnormal platelet aggregation to ADP
Thrombocytopenia and giant platelets
When performing platelet aggregation studies, which set of platelet aggregation results would most likely be associated with Bernard–Soulier syndrome?
A. Normal platelet aggregation to collagen, ADP, and ristocetin
B. Normal platelet aggregation to collagen, ADP, and epinephrine; decreased aggregation to ristocetin
C. Normal platelet aggregation to epinephrine and ristocetin; decreased aggregation to collagen and ADP
D. Normal platelet aggregation to epinephrine, ristocetin, and collagen; decreased aggregation to ADP
Normal platelet aggregation to collagen, ADP, and epinephrine; decreased aggregation to ristocetin
Which set of platelet responses would be most likely associated with Glanzmann’s thrombasthenia?
A. Normal platelet aggregation to ADP and ristocetin; decreased aggregation to collagen
B. Normal platelet aggregation to collagen; decreased aggregation to ADP and ristocetin
C. Normal platelet aggregation to ristocetin; decreased aggregation to collagen, ADP, and epinephrine
D. Normal platelet aggregation to ADP; decreased aggregation to collagen and ristocetin
Normal platelet aggregation to ristocetin; decreased aggregation to collagen, ADP, and epinephrine
Which of the following is a characteristic of acute immune thrombocytopenic purpura?
A. Spontaneous remission within a few weeks
B. Predominantly seen in adults
C. Nonimmune platelet destruction
D. Insidious onset
Spontaneous remission within a few weeks
TTP differs from DIC in that:
A. APTT is normal in TTP but prolonged in DIC
B. Schistocytes are not present in TTP but are present in DIC
C. Platelet count is decreased in TTP but normal in DIC
D. PT is prolonged in TTP but decreased in DIC
APTT is normal in TTP but prolonged in DIC
Several hours after birth, a baby boy develops petechiae and purpura and a hemorrhagic diathesis. The platelet count is 18 × 109/L. What is the most likely explanation for the low platelet count?
A. Drug-induced thrombocytopenia
B. Secondary thrombocytopenia
C. Neonatal alloimmune thrombocytopenia
D. Neonatal DIC
Neonatal alloimmune thrombocytopenia
Which of the following is associated with post-transfusion purpura (PTP)?
A. Nonimmune thrombocytopenia/alloantibodies
B. Immune-mediated thrombocytopenia/alloantibodies
C. Immune-mediated thrombocytopenia/autoantibodies
D. Nonimmune-mediated thrombocytopenia/autoantibodies
Immune-mediated thrombocytopenia/alloantibodies
Hemolytic uremic syndrome (HUS) is associated with:
A. Fever, thrombocytosis, anemia, and renal failure
B. Fever, granulocytosis, and thrombocytosis
C. Escherichia coli 0157:H7
D. Leukocytosis and thrombocytosis
Escherichia coli 0157:H7
Storage pool deficiencies are defects of:
A. Platelet adhesion
B. Platelet aggregation
C. Platelet granules
D. Platelet production
Platelet granules
Lumi-aggregation measures:
A. Platelet aggregation only
B. Platelet aggregation and ATP release
C. Platelet adhesion
D. Platelet glycoprotein Ib
Platelet aggregation and ATP release
Neurological findings may be commonly associated with which of the following disorders?
A. HUS
B. TTP
C. ITP
D. PTP
TTP
Hereditary hemorrhagic telangiectasia is a disorder of:
A. Platelets
B. Clotting proteins
C. Fibrinolysis
D. Connective tissue
Connective tissue
Which of the following prevents platelet aggregation?
A. Thromboxane A2
B. Thromboxane B2
C. Prostacyclin
D. Antithrombin
Prostacyclin
Which of the following instruments can be used to evaluate platelet function?
A. Platelet aggregometer
B. VerifyNow
C. PFA-100
D. All of the above
All of the above
Which defect characterizes Gray’s syndrome?
A. Platelet adhesion defect
B. Dense granule defect
C. Alpha granule defect
D. Coagulation defect
Alpha granule defect
The P2Y12 ADP receptor agonist assay may be used to monitor platelet aggregation inhibition to which of the following drugs?
A. Warfarin
B. Heparin
C. LMWH
D. Clopidogrel (Plavix)
Clopidogrel (Plavix)
Which of the following is not a cause of thrombocytopenia?
A. Splenomegaly
B. Chemotherapy
C. Increased thrombopoietin
D. Aplastic anemia
Increased thrombopoietin
Platelets interacting with and binding to other platelets is referred to as
A. Adhesion
B. Aggregation
C. Release
D. Retraction
Aggregation
In 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
Release of endogenous ADP
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 flow of current between two electrodes.
D. Pulse editing: Editing electronically generated pulses can differentiate the number of free platelets versus platelet aggregates.
Change in optical density: As platelets aggregate, the optical density of the platelet-rich plasma decreases.
Of the following therapeutic agents, those considered to be antiplatelet medications are
A. Aspirin and Plavix®
B. Coumadin® and heparin
C. Heparin and protamine sulfate
D. Tissue plasminogen activator and streptokinase
Aspirin and Plavix®
A potent inhibitor of platelet aggregation released by endothelial cells is
A. Epinephrine
B. Prostacyclin
C. Ristocetin
D. Thromboxane A2
Prostacyclin
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
8-10 fL
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
Variation in platelet cell size
Which of the following is not a normal maturation stage for platelets?
A. Megakaryoblast
B. Promegakaryocyte
C. Micromegakaryocyte
D. Megakaryocyte
Micromegakaryocyte
Which of the following platelet aggregating agents demonstrates a monophasic aggregation curve when used in optimal concentration?
A. Thrombin
B. Collagen
C. Adenosine diphosphate (ADP)
D. Epinephrine
Collagen
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. Vitamin K
D. Protein C
Vitamin C
The number of platelets an average megakaryocyte generates is approximately
A. 25-50
B. 50-200
C. 200-500
D. 2000-4000
2000-4000
Which of the following is correct regarding
acquired thrombotic thrombocytopenic purpura?
A. Autoimmune disease
B. Decreased VWF
C. Decreased platelet aggregation
D. Decreased platelet adhesion
Autoimmune disease
