AACC Hematology & Coagulation 2

Question 1

Which coagulation factor is deficient in classic Hemophilia A?

Accepted Answer

Factor VIII

Answer

Factor IX

Answer

Factor VII

Answer

Factor XI

Question 2

The prothrombin time (PT) primarily evaluates which coagulation pathway?

Accepted Answer

Extrinsic and common pathways

Answer

Intrinsic pathway only

Answer

Intrinsic and common pathways

Answer

Fibrinolytic pathway

Question 3

Which laboratory test is the standard for monitoring unfractionated heparin (UFH) therapy?

Accepted Answer

Activated partial thromboplastin time (aPTT)

Answer

Prothrombin time (PT)

Answer

Thrombin time (TT)

Answer

Anti-Xa activity assay

Question 4

What is the mechanism of action of warfarin as an anticoagulant?

Accepted Answer

Inhibition of vitamin K–dependent carboxylation of Factors II, VII, IX, and X

Answer

Direct inhibition of thrombin (Factor IIa)

Answer

Binding to antithrombin III to inhibit Factor Xa

Answer

Blocking platelet ADP receptors to prevent aggregation

Question 5

A patient presents with prolonged bleeding time, normal PT, and normal aPTT. Which condition is most likely?

Accepted Answer

Von Willebrand disease or platelet dysfunction

Answer

Hemophilia A

Answer

Vitamin K deficiency

Answer

Factor V Leiden mutation

Question 6

Which coagulation pathway is initiated by the exposure of tissue factor (thromboplastin) to blood?

Accepted Answer

Extrinsic pathway

Answer

Intrinsic pathway

Answer

Common pathway

Answer

Fibrinolytic pathway

Question 7

What is the role of fibrinogen (Factor I) in secondary hemostasis?

Accepted Answer

Serving as the substrate for thrombin to generate fibrin clot

Answer

Activating Factor XIII to crosslink fibrin

Answer

Inhibiting plasminogen to prevent premature fibrinolysis

Answer

Chelating calcium to stabilize clot formation