heme externship - coag 2.1-2.2 Flashcards

1
Q

which of the following initiates in vivo coagulation by activation of factor VII
A. protein C
B. tissue factor
C. plasmin activator
D. thrombomodulin

A

B. tissue factor
- tissue factor + calcium activates FVII in extrinsic pathway

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2
Q

which of the following clotting factors plays a role in clot formation in virto, but not in vivo
A. FVIIa
B. FIIa
C. FXIIa
D. FXa

A

C. FXIIa
- bypassed by contact activation in test systems

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3
Q

the anticoagulant of choice for most routine coagulation studies is
A. sodium oxalate
B. sodium citrate
C. heparin
D. EDTA

A

B. sodium citrate

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4
Q

which anticoagulant:blood ratio is correct for coagulation procedures
A. 1:4
B. 1:5
C. 1:9
D. 1:10

A

C. 1:9

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5
Q

which resutls would be expected for PT and APTT in a patient with polycythemia
A. both prolonged
B. both shortened
C. normal, prolonged APTT
D. both normal

A

A. prolonged
- due to excess anticoagulant and low plasma volume

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6
Q

which reagents are used in the PT test
A. thromboplastin and sodium chloride
B. thromboplastin and potassium chloride
C. thromboplastin and calcium
D, actin and calcium chloride

A

C. thromboplastin and calcium

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7
Q

which test would be abnormal in a patient with FX deficiency
A. PT only
B. APTT only
C. PT and APTT
D> TT

A

C. PT and APTT
- FX is in common pathway so both are impacted

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8
Q

which clotting factor is NOT measured by the PT and APTT tests
A. FVIII
B. FIX
C. FV
D. FXIII

A

D. FXIII
- necessary for clot stabilization in vivo but not measured

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9
Q

a modification of which procedure can be used to measure fibrinogen
A. PT
B. APTT
C. TT
D. fibrin degradation products

A

C. TT

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10
Q

which of the following characterized vitamin K
A. it is required for biological activity of fibrinolysis
B. its activity is enhanced by heparin therapy
C. it is required for carboxylation of glutamate residues of some coagulation factors
D. it is made by endothelial cells

A

C. it is required…
- magic 4 factors (II, VII, IX, X) need to be carboxylated to be functional in the liver

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11
Q

which fragments of fibrin clot degradation are measured by the D-dimer test
A. fragments X and Y
B. fibrinopeptide A and B
C, fragments of D and E
D. D-D domains

A

D. D-D domains
- present in ONLY secondary fibrinolysis

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12
Q

which of the following clotting facotrs are measured by the APTT test
A. II, VII, IX, X
B. VII X, V, II, I
C. XII, XI, IX, VII, X, V, II, I
D. XII, VII, X, V, II, I

A

C. intrinsic pathway

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13
Q

which coagulation test(s) would be abnormal in a patient with vitamin K deficiency
A. PT only
B. PT and APTT
C. fibrinogen level
D. TT

A

B. PT and APTT
- Factors: II, VII, IX, X impacted

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14
Q

which of the following is correct regarding the INR
A. it uses the international sensitivity ratio (ISR)
B. it standardized PT results
C. it standardizes APTT results
D. it is used to monitor heparin therapy

A

B. it standardizes PT results

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15
Q

which of the following is referred to as an endogenous activator of plasminogen
A. streptokinase
B. transamidase
C. tissue plasminogen activator (tPA)
D. tPA inhibitor

A

C. tPA
- released from endothelial cells by protein C

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16
Q

which protein is the primary inhbitor of the fibrinolytic system
A. protein C
B. protein S
C. alpha2-antiplasmin
D. alpha2-macroglobulin

A

C. alpha2-antiplasmin
- binds free plasmin

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17
Q

which of the following statements is correct regarding the D-dimer test
A. levels are decreased in DIC
B. test detects polypeptides A and B
C. test detects fragments of D and E
D. test has a negative predictive value

A

D. test has a negative preditive value
- probability that a negative result is free of disease

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18
Q

a protein that plays a role in both cogulatin and PLT aggregatin is:
A. FI
B. FVIII
C. FIX
D. FXI

A

A. FI (fibrinogen)
- platelets use fibrinogen to aggregate together

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19
Q

a standard 4.5 mL blue top tube filled with 3.0 mL of blood was submitted to the lab for PT and APTT. the sample is from a patient undergoing surgery the following morning for a tonsillectomy. Which of the following is necessary course of action by the medical lab scientist
A. run both tests in duplicate and report the average result
B. reject the sample and request a new sample
C. report the PT
D. report the APTT

A

B. reject due to nonsufficient quantitiy

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20
Q

which statement is correct regarding sample storage for the PT test
A. stable for 24 hours if the sample is capped
B. stable for 24 hours if the sample is refrigerated at 4C
C. stable for 4 hours if the sample is stored at 4 C
D. should be run within 8 hours

A

A. stable if capped
- if refrigetated can cold activate FVII
- APTT results are stable if refrigerated for 4 hours

21
Q

in primary fibrinolysis, the fibrinolytic activity results in response to
A. increased fibrin formation
B., spontaneous activation of fibrinolysis
C. increased fibrin monomers
D. DIC

A

B. spontaneous activation of fibrinolysis
- fibrinogenolysis is always pathogenic

22
Q

plasminogen deficiency is associated with:
A. bleeding
B. thrombosis
C. increased fibrinolysis
D. increased coagulation

A

B. thrombosis
- no clot breakdown

23
Q

which of the following clotting factors are activated by thrombin that is generated by tissue pathway (F-VIIa)
A. FXII and XI
B. FXII and I
C. FI and II
D. FV and VIII

A

D. FV and VIII

24
Q

which substrate is used in chromogenic factor assay
A. pNa
B. chlorphenol red
C. prussian blue
D. ferricyanise

A

A. pNa

25
Q

which of the following antibodies is used in the D-dimer assay
A. polyclonal antibody directed against X and Y
B. polyclonat antibody directed against D-dimer
C. monoclonal antibody against D and E fragments
D. monoclonal antibody against D-dimer

A

D. monoclonal antibody against D-dimer

26
Q

thrombotic thrombocytopenic purpura (TTP) is characterized by:
A. prolonged PT
B. increased PLT aggregation
C. thrombocytosis
D. prolonged APTT

A

B. increased PLT aggregation
- increased activation of platelets

27
Q

thrombocytopenia may be associated with
A. splenectomy
B. hypersplenism
C. acute blood loss
D. increased proliferation of pluripoten stem cells

A

B. hypersplenism
- increased platelet sequestration

28
Q

aspirin prevents PLT aggregation by inhibiting the action of which enzyme
A. phospholipase
B. cyclo-oxygenase
C. thrombazanse A2 synthase
D. prostacyclin synthetase

A

B. cyclo-oxygenase
- prevents cyclo-oxygenase from forming TXa2

29
Q

normal PLT adhesion depends on:
A. fibrinogen
B. glycoprotein 1b
C. glycoprotein IIb-IIIa
D. calcium

A

B. glycoprotein 1b
- platelet receptor for vWF to bind to collagen

30
Q

which of the following test results is normal in patient with classic vWF disease
A. PLT aggregation
B. APTT
C. PLT count
D. FVIII:C and vWF levels

A

D. PLT count

31
Q

Bernard Soulier syndrome is associated with
A. decreased FIX
B. decreased FVIII
C. thrombocytopenia and giant PLTs
D. abnormal PLT function test results

A

C. thrombocytopenia and giant PLTs

32
Q

when performing PLT aggregation studies, which set of PLT aggregation results would most likleu be associated with BS syndrome
A. normal PLT aggregation to collagen, ADP, and ristocetin
B. normal PLT aggregation to collagen. ADP and EPI; decreased aggregation in ristocetin
C. normal PLT aggregation to EPI and ristocetin; decreased aggregation to collagen and ADP
D. Normal PLT aggregation to EPI, ristocetin and collagen; decreased aggregation to ADP

A

B. decreased with ristocetin
- ristocetin measures agglutination not aggregation = measures 1b-vWF complexing

33
Q

which set of PLT responses would be most likely associated with Glansmann thrombasthemia
A. normal aggregation to ADP and ristocetin; decreased with collagen
B. normal aggregation to collagen; decreased to ADP and ristocetin
C. normal to ristocetin; decreased to collagen, ADP and EPI
D. normal to ADP; decreased to collagen and ristocetin

A

C.
- missing IIb-IIIa so no normal aggregation curves; since ristocetin measures agglutination with vWF and Ib it would be normal

34
Q

which of the following is characteristic of acute immune thrombocytopenic purpura
A. spontaneous remission within a few weeks
B. predominantly seen in adults
C. nonimmune PLT destruction
D. insidious onset

A

A. spontaneous remission
- noramlly in children after a viral infection

35
Q

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. plt count is decreased in TTP but normal in DIC
D. PT is prolonged in TTP but decreased in DIC

A

A.
- TTP is a platelet disorder so will not impact APTT

36
Q

several hours after birth, a baby boy develops petechiae and purpura and hemorrhagic diathesis. The PLT count is 18*10^9/L. What is the most likely explanation for the low PLT count
A. durg induced thrombocytopenia
B. secondary thrombocytopenia
C. neonatal alloimmune thrombocytopenia
D. neonatal DIC

A

C. neonatal alloimmune thrombocytopenia
- usually Hpa-1a antibody

37
Q

which of the following is associated with post transfuion purpura (PTP)
A. nonimmune thrombocytopenia/alloantibodies
B. immune mediated thrombocytopenia/alloantibodies
C. immune mediated thrombocytopenia/autoantibodies
D. nonimmune-mediated thrombocytopenia/autoantibodies

A

B. immune mediated penia/alloantibodies

38
Q

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

A

C.

39
Q

storage pool deficiencies are defects of:
A. plt adhesion
B. plt aggregation
C. plt granules
D. plt production

A

C. plt granules

40
Q

Lumi-aggregation measures
A. aggregation only
B. aggregation and ATP release
C. adhesion
D. glycoprotein Ib

A

B. aggregation and ATP release
- whole blood diluted with saline, impedance measures aggregation and lumi measures ATP release with luciferin
- no luciferin release in storage pool disorders

41
Q

neurological findings may be commonly associated with which of the following disorders
A. HUS
B. TTP
C. ITP
D. PTP

A

B. TTP

42
Q

which of the following is correct regarding acquired TTP
A. autoimmune disease
B. decreased vWF
C. decreased PLT aggregation
D. decreased PLT adhesion

A

A.
- autoimmune disease with antibodies against adamts13

43
Q

hereditary hemorrhagic telangiectasia is a disorder of:
A. PLTs
B. clotting proteins
C. fibrinolysis
D. connective tissue

A

D. connective tissue

44
Q

which of the following prevents PLT aggregation
A. TXa2
B. thromboxane B2
C. prostacyclin
D. antithrombin

A

C. prostacyclin

45
Q

which defect characterizes gray platelet syndrome
A. PLT adhesio ndefect
B. dense granule defect
C. alpha granule defect
D. coagulation defect

A

C. alpha granules

46
Q

the P2Y12 ADP receptor agonist assay may be used to monitor PLT aggregation inhibition to which of the following drugs
A. warfarin
B. heparin
C. LMWH
D. clopidogrel (plavix)

A

D. plavix
- only drug listed that related to platelets

47
Q

which of the following instruents can be used to evaluate PLT function
A. plt aggregometer
B. verify now
C. pfa 100
D. all

A

D. all

48
Q

which of the following PLT aggregating agens demonstrates a monophasic aggregation curve when used in the optimal concentration
A. thrombin
B. collagen
C. ADP
D. EPI

A

B. collagen