Hemostasis and Blood Clotting Quiz

The activation of factor X occurs in

• the intrinsic pathway only.

• the extrinsic pathway only.

• both the intrinsic and extrinsic pathways.

• neither the intrinsic nor extrinsic pathway.

Platelets

• form a plug by sticking to each other.

• release chemicals that stimulate vasoconstriction.

• provide phospholipids needed for the intrinsic pathway.

• serve all of these functions

Platelets

• release ADP after activation

• are also called megakaryocytes

• can only be activated via their glycoprotein receptors

• have dense vesicles containing histamine

During primary homeostasis

• A fibrinogen is converted to fibrin

• B the initial vasoconstriction does not require platelet activation

• C thromboxane A2 causes platelet adhesion

• D activation of lipoxygenase is a vital step

Activation of thrombin

• A is triggered by thrombomodulin

• B always requires the presence of activated platelets

• C is Ca2+ independent

• D depends on Factor X

Fibrin

• A requires Factor XIII to polymerize

• B is destroyed by active protein C

• C binds plasminogen

• D activates von Willebrand factor

Which of the following is NOT one of the four major physiologic events of hemostasis?

• A. Fibrinolysis

• B. Vasodilatation

• C. Platelet plug formation

• D. Fibrin production

Which is required for platelet adherence to injured endothelium?

• A. Thromboxane A2

• B. Glycoprotein (GP) IIb/IlIa

• C. Adenosine diphosphate (ADP)

• D. Von Willebrand factor (vWF)

Which of the following clotting factors is the first factor common to both intrinsic and extrinsic pathways?

• A. Factor I (fibrinogen)

• B. Factor IX (Christmas factor)

• C. Factor X (Stuart-Prower factor)

• D. Factor XI (plasma thromboplasma antecedent)

Which of the following is the correct sequence of events leading to blood clotting?

• vasoconstriction, platelet aggregation, coagulation

• platelet aggregation, vasoconstriction, coagulation

• Vasoconstriction, coagulation, platelet aggregation