coag study guide

1. Aspirin prevents platelet aggregation by inhibiting the action of which enzyme?

a. Phospholipase

b. Cyclooxygenase

c. Prostacyclin synthetase

d. Thromboxane A2 synthetase

b. Cyclooxygenase

In platelet aggregation studies, the second phase of aggregation is directly related to:

a. Activation of plasmin

b. Formation of fibrin

c. Changes in platelet shape

d. Release of endogenous ADP

d. Release of endogenous ADP

Laboratory results in acute DIC are:

a. Decreased fibrinogen, decreased platelet count, increased D-Dimer

b. Increased fibrinogen, decreased platelet count, increased D-Dimer

c. Increased fibrinogen, decreased platelet count, decreased D-Dimer

d. Decreased fibrinogen, decreased platelet count, decreased D-Dimer

a. Decreased fibrinogen, decreased platelet count, increased D-Dimer

Routine coagulation tests have been performed on a properly collected specimen. The PT was prolonged and the APTT is normal. The likely abnormality is:
a. hypogammaglobulinemia
b. low platelet count
c. Factor X deficiency
d. Factor VII deficiency

d. Factor VII deficiency

The following coagulation results were obtained on a 10-year-old male child:
PT = 11.8 seconds
APTT = 30.0 seconds
TT = 10 seconds
Fibrinogen = 380 mg/dL
These results are most suggestive of:

a. Factor VIII deficiency
b. hypofibrinogenemia
c. normal results
d. Factor VII deficiency

c. normal results

In storage pool diseases, platelets are primarily deficient in:
a. Platelet Factor 4
b. ADP
c. Platelet Factor 3
d. Thrombasthenin

b. ADP

The ratio of anticoagulant to blood for coagulation procedures should be 1 to
a. 10
b. 7

c. 9
d. 4.5

c. 9

A major distinction between the extrinsic and intrinsic pathways of coagulation is:

a. Vitamin K dependent factors are required for the intrinsic pathway
b. The intrinsic pathway is only activated by enzymes

c. Tissue factors are required for activation of the extrinsic pathway
d. Coagulation inhibitors affect only the intrinsic pathway

c. Tissue factors are required for activation of the extrinsic pathway

Measurement of the time required for fibrin formation when thrombin is added to recalcified plasma evaluates:

a. Prothrombin consumption

b. Prothrombin concentration

c. The extrinsic system

d. Fibrinogen levels

d. Fibrinogen levels

A PTT mixing studies was performed and the results are as follows:

Result after Immediate Mixing = Prolonged

Result after 1 hour 37C incubation = Prolonged

What is the possible cause?

a. Factor VIII deficiency

b. Lupus Anticoagulant

c. Factor VII deficiency

d. Factor VIII inhibitor

b. Lupus Anticoagulant

Which of the following tests will be affected if a patient has decreased levels of Factor V?

a. neither APTT or PT

b. both APTT and PT

c. PT

d. APTT

b. both APTT and PT

Endothelial cells lining vessel walls release products involved in all of the following functions EXCEPT:

a. Inhibiting platelet aggregation

b. Neutralizing thrombin

c. Activating the fibrinolytic system

d. Initiating fibrin formation

a. Inhibiting platelet aggregation

The end point detection in the D-dimer test is based on:

a. photo-optical

b. mechanical

c. chromogenic

d. immunologic

d. immunologic

The factor that can be activated by both the intrinsic and extrinsic pathway is:

a. Factor XII

b. Factor V

c. Factor X

d. Factor VIII

c. Factor X

A patient's results are:low Protein S activity, decreased free PS antigen, and decreased total PS antigen. The next step in analysis should be:
a. aPTT
b. C4b-BP assay
c. PT
d. familial study for males only

b. C4b-BP assay

Christmas disease is another name for which deficiency?
a. Factor IX
b. Factor II
c. Factor XI
d. Factor VIII

a. Factor IX

Which of the following platelet responses is most likely associated with classic von Willebrand's disease?

a. Absent aggregation to epinephrine, ADP, and collagen

b. Decreased amount of ADP in platelets

c. Normal platelet aggregation to ristocetin

d. Decreased platelet aggregation to ristocetin

d. Decreased platelet aggregation to ristocetin

Initiation of plasminogen to plasmin which results in fibrinolysis occurs by:

a. alpha2-antiplasmin

b. tissue-type plasminogen activator (tPA)

c. Plasminogen activator inhibitor (PAI-1)

d. alpha2-macroglobulin

b. tissue-type plasminogen activator (tPA)

Which of the following is characteristic of platelet disorders?

a. Deep muscle hemorrhages

b. Severely prolonged clotting time

c. Retroperitoneal hemorrhages

d. Vascular damage

d. Vascular damage

In TTP, a deficiency of ADAMTS-13 causes clotting because of:

a. Inability to cleave ULVWF

b. Increased VWF

c. Increased platelet production

d. Increased production of thrombin

a. Inability to cleave ULVWF

A hemophiliac male and a normal female can produce a:

a. Female carrier

b. Male carrier

c. Male hemophiliac

d. Normal female

a. Female carrier

Coagulation factors affected by coumadin drugs are:

a. II,V, and VII

b. VIII,IX and X

c. I,II,V, and VII

d. II,VII, IX, and X

d. II,VII, IX, and X

What plasma protein should be assayed when platelets fail to aggregate?

a. collagen

b. fibrinogen

c. von Willebrand factor

d. thrombin

b. fibrinogen

Daily platelet counts were performed on a patient who started on heparin therapy. On the 5th day after therapy started, the platelet count suddenly dropped from the usual 300,000/µl to 50,000/µl. What is the most likely reason for the decrease in the platelet count?

a. The patient was developing ITP

b. The spleen was sequestering more platelet because of the heparin therapy

c. The patient was developing heparin-induced thrombocytopenia

d. The patient was developing aplastic anemia

c. The patient was developing heparin-induced thrombocytopenia

In a Bethesda Assay, 1 Bethesda Unit equals to:

a. 60% of the remaining factor activity

b. 55% of the remaining factor activity

c. 50% of the remaining factor activity

d. 25% of the remaining factor activity

c. 50% of the remaining factor activity

What method is most helpful in differentiating a Factor VIII Inhibitor from a Hemophilia B?

a. Mixing studies

b. Pattern of inheritance

c. APTT

d. Clinical history

a. Mixing studies

A 55-year old woman is admitted with a pulmonary embolus and treated with an antithrombolytic agent. Which of the following tests would be useful in monitoring this therapy?

a. PT

b. D-Dimer

c. Vitamin K

d. Bleeding time

b. D-Dimer

Thrombin-thrombomodulin complex is necessary for activation of:

a. Factors V and VIII

b. Antithrombin

c. Protein C

d. Protein S

c. Protein C

Prothrombin is also known as:

a. Factor V

b. Factor III

c. Factor I

d. Factor II

d. Factor II

Bleeding doesn't correlate well with factor levels in a deficiency of:

a. Factor IX

b. Factor XI

c. Factor VII

d. Factor VIII

b. Factor XI

A test which determines the rate of fibrin formation under a standardized set of conditions is the:

a. Bleeding time

b. Activated Partial Thromboplastin Time

c. Clot retraction time

d. D-Dimer test

b. Activated Partial Thromboplastin Time

32. Which of the following factors can contribute to hypercoagulation?

a. Hypogammaglobulinemia

b. Vascular endothelial damage

c. Increased blood flow

d. Decreased platelets

b. Vascular endothelial damage

During heparin anticoagulation which of the following tests is commonly used to monitor therapy:

a. Activated Partial Thromboplastin Time

b. Reptilase time

c. Thrombin Time

d. Prothrombin Time

a. Activated Partial Thromboplastin Time

In classical Hemophilia A the PTT is increased as a result of:

a. Vitamin K deficiency

b. A low platelet count

c. Deficiency of active Factor VIII

d. Inadequate synthesis of prothrombin

c. Deficiency of active Factor VIII

Which of the following symptoms is least likely to occur with hemophilia A or B?

a. Deep muscular bleeding

b. Delayed bleeding

c. Spontaneous joint bleeding

d. Petechiae

d. Petechiae

The prothrombin time tests for:

a. Factor V

b. All of the above

c. Factor VII

d. Factor II

b. All of the above

A 28-year old man suffered from recurrent deep venous thrombosis and pulmonary embolus. Studies in the laboratory show that his plasma is unable to inhibit factors VIIIa and Va, indicating the plasma is deficient in which naturally occurring anticoagulant?

a. Antithrombin

b. Fibronectin

c. Protein C

d. HMWK

c. Protein C

A patient with Stuart-Prower deficiency is deficient in:

a. Factor VIII

b. Factor X

c. Factor V

d. Factor XIII

b. Factor X

A modification of which procedure can be used to measure fibrinogen?

a. PT

b. Thrombin time

c. APTT

d. Fibrin degradation products

b. Thrombin time

Which test result will be abnormal in a patient with dysfibrinogenemia?

a. APTT

b. Thrombin Time

c. Immunologic fibrinogen level

d. PT

c. Immunologic fibrinogen level

41. Of the factors listed below, which may be deficient with either no bleeding or only a minor tendency, even after trauma or surgery?

a. X

b. XIII

c. V

d. XII

d. XII

If the APTT screening test for lupus anticoagulant is positive, a confirmatory follow

up test is:

a. Factor XIII assay

b. Bleeding Time

c. Mixing Study

d. Dilute Russell's Viper Venom

d. Dilute Russell's Viper Venom

Which of the following proteins is the major inhibitory protein involved in controlling blood coagulation?

a. Alpha2 antiplasmin

b. Protein S

c. Protein C

d. Alpha2 macroglobulin

a. Alpha2 antiplasmin

Factor V Leiden promotes thrombosis by preventing:

a. Deactivation of factor Va

b. Activation of protein S

c. Activation of factor V

d. Activation of protein C

a. Deactivation of factor Va

Which of the following is a primary endogenous plasminogen activator?

a. Stuart-Prower factor

b. Streptokinase

c. Tissue plasminogen activator (t-PA)

d. TAFI

c. Tissue plasminogen activator (t-PA)

A patient has a medical history as an infant of bleeding from the umbilical cord site.Now, as an adult, he experiences poor wound healing. Current laboratory studies reveal PT, APTT, TT, platelet count and platelet functional assays results are all normal. What factor deficiency could exist?

a. Factor XIII

b. Prothrombin

c. Factor XII

d. Fibrinogen

a. Factor XIII