Question 1

Which domain of the blood coagulation protein is responsible for its distinctive identity?&#10;A) Signal peptide domain&#10;B) Catalytic domain&#10;C) Epidermal growth factor domain&#10;D) Noncatalytic domain

Accepted Answer

The noncatalytic domain, also known as the variable region or the regulatory domain, is responsible for the distinctive identity of blood coagulation proteins. This region varies greatly between different clotting factors and is involved in the regulation of coagulation.

Question 2

Hemostasis depends on which of the following?&#10;A) The interaction between coagulation and fibrinolysis inhibitors&#10;B) The interaction between platelets, coagulation proteins, and blood vessels&#10;C) The rate of platelet destruction&#10;D) The rate of endothelial cell turnover

Accepted Answer

Hemostasis involves the interaction between platelets, coagulation proteins, and blood vessels. Platelets play a crucial role in forming a platelet plug at the site of injury, while coagulation proteins facilitate the formation of a fibrin clot to strengthen the plug. Blood vessels also contribute to hemostasis by constricting to limit blood loss and by producing substances that inhibit coagulation. The interaction between these factors is essential for successful hemostasis. The other options, such as the interaction between coagulation and fibrinolysis inhibitors, the rate of platelet destruction, and the rate of endothelial cell turnover, are important factors that can affect hemostasis but are not the primary driver of the process.

Question 3

Which of the following degrades factors V and VIII?&#10;A) TFPI&#10;B) SERPINs&#10;C) Proteins C and S&#10;D) APS

Accepted Answer

Proteins C and S degrade factors V and VIII through a calcium-dependent reaction to prevent excessive clotting. TFPI and SERPINs are inhibitors of coagulation factors, while APS is an antiphospholipid antibody that can cause clotting disorders.

Question 4

Which of the following is primarily responsible for neutralizing the extrinsic tenase (Xase) complex?&#10;A) TFPI&#10;B) SERPINs&#10;C) Proteins C and S&#10;D) APS

Accepted Answer

TFPI (tissue factor pathway inhibitor) is primarily responsible for neutralizing the extrinsic tenase (Xase) complex. TFPI inhibits the activation of factor X by forming a complex with factor VIIa and tissue factor. This prevents the formation of additional thrombin and helps to regulate the coagulation cascade. SERPINs (serine protease inhibitors), proteins C and S, and APS (antiphospholipid syndrome) also play roles in regulating coagulation, but they are not primarily responsible for neutralizing the extrinsic tenase (Xase) complex.

Question 5

The role of vitamin K in hemostasis is to:&#10;A) Promote contact factor activation&#10;B) Facilitate calcium binding to essential factors&#10;C) Initiate extrinsic pathway activation&#10;D) Cross-link the fibrin monomers

Accepted Answer

Vitamin K is essential for the post-translational modification of several clotting factors, including prothrombin, factors VII, IX, and X, and proteins C, S, and Z. Vitamin K-dependent carboxylation of these factors creates calcium-binding sites, which are necessary for their function in the clotting cascade. Without adequate vitamin K, these factors are unable to bind calcium and therefore cannot participate in clot formation.

Question 6

The substance directly responsible for the physical breakdown of the thrombus is:&#10;A) Plasmin&#10;B) Plasminogen&#10;C) Tissue plasminogen activator&#10;D) Fibrin

Accepted Answer

Plasmin is the enzyme responsible for directly breaking down the fibrin in a blood clot or thrombus. It is formed from its inactive precursor plasminogen, which is converted to plasmin by tissue plasminogen activator (tPA) or urokinase plasminogen activator (uPA). Fibrin is the protein that forms the backbone of a thrombus, but it is not directly responsible for its breakdown.

Question 7

Which of the following is not formed on a phospholipid surface?&#10;A) Extrinsic Xase&#10;B) Intrinsic Xase&#10;C) Prothrombinase&#10;D) Factor VIIa

Accepted Answer

Factor VIIa is not formed on a phospholipid surface; it circulates in the blood and becomes active upon binding to tissue factor.

Question 8

Platelet activation and subsequent formation of the platelet plug are involved in:&#10;A) Primary hemostasis&#10;B) Secondary hemostasis&#10;C) Fibrinolysis&#10;D) Inhibitory system

Accepted Answer

Platelet activation and subsequent formation of the platelet plug are key events in primary hemostasis, which involves the initial response to vessel injury to temporarily stop bleeding. Secondary hemostasis involves the coagulation cascade and production of fibrin, while fibrinolysis is the process of breaking down fibrin clots. The inhibitory system refers to mechanisms that prevent excessive clotting.

Question 9

Which of the following coagulation factors is(are) found in the extrinsic pathway?&#10;A) HK and FXII&#10;B) FXI and FIX&#10;C) FVII and TF&#10;D) FX

Accepted Answer

FVII and tissue factor (TF) are the critical factors in the extrinsic pathway, which is activated by tissue injury.

Question 10

Why is vitamin K necessary for some coagulation proteins to become functional?&#10;A) Vitamin K activates coagulation zymogens.&#10;B) Vitamin K binds coagulation factors to a phospholipid surface.&#10;C) Vitamin K combines with VWF in the circulation.&#10;D) Vitamin K is required for gamma-carboxylation of glutamic acid residues.

Accepted Answer

Vitamin K is necessary for gamma-carboxylation of glutamic acid residues in some coagulation proteins, which allows them to interact with calcium and phospholipids on platelet surfaces and become functional. Without vitamin K, these proteins would not be able to bind to the necessary surfaces and form clots to stop bleeding.

Question 11

Which of the following is responsible for urokinase-catalyzed plasminogen (PLG) activation?&#10;A) ADAMTS-13&#10;B) LRP&#10;C) UPAR&#10;D) EPCR

Accepted Answer

The answer of Which of the following is responsible for...

Question 12

Activation of circulating zymogens is achieved through:&#10;A) Sympathetic nervous system stimulation&#10;B) Endomitosis&#10;C) Splenic sequestration&#10;D) Proteolytic cleavage

Accepted Answer

The answer of Activation of circulating zymogens is achieved through:&#10;A)...

Question 13

Which of the following is not involved in &#34;contact activation&#34;?&#10;A) Factor XII&#10;B) Factor XI&#10;C) PK&#10;D) Factor X

Accepted Answer

The answer of Which of the following is not involved...

Question 14

Which plasminogen activator (PA) is distinctive among the serine proteases because it does not circulate as a zymogen but is fully active toward its substrate plasminogen in a single-chain form?&#10;A) uPA&#10;B) uPAR&#10;C) PLG&#10;D) tPA

Accepted Answer

The answer of Which plasminogen activator (PA) is distinctive among...

Question 15

The prothrombin group includes of which of the following?&#10;A) Factor V&#10;B) Factor VII&#10;C) Factor XII&#10;D) Factor VIII

Accepted Answer

The answer of The prothrombin group includes of which of...

Question 16

All of the following are necessary for a clot to form except:&#10;A) Platelets&#10;B) Coagulation protein&#10;C) Plasmin&#10;D) Endothelial cells

Accepted Answer

The answer of All of the following are necessary for...

Question 17

Which of the following is the smallest degradation product of fibrin?&#10;A) Fragment X&#10;B) Fragment Y&#10;C) D-dimer&#10;D) E fragment

Accepted Answer

The answer of Which of the following is the smallest...

Question 18

Triggering the contact activation factors of the intrinsic pathway does not require which of the following components? A) Vitamin K B) Calcium C) Serine protease D) Kinins

Accepted Answer

The answer of Triggering the contact activation factors of the...

Question 19

What is the key component in secondary hemostasis that binds the platelets into a solid plug?&#10;A) Fibrin&#10;B) Tissue factor&#10;C) Plasminogen&#10;D) Thrombin

Accepted Answer

The answer of What is the key component in secondary...

Question 20

Which of the following is responsible for cleaving ultra-large VWF multimers into functional units?&#10;A) LRP&#10;B) ADAMTS-13&#10;C) EPCR&#10;D) UPAR

Accepted Answer

The answer of Which of the following is responsible for...

Question 21

Compare and contrast systemic and physiologic fibrinolysis.

Accepted Answer

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Question 22

What reflex test should be done on a patient with an abnormal APTT who is suspected of having hemophilia?&#10;A) Platelet function assay&#10;B) Factor assay&#10;C) Quantitative fibrinogen assay&#10;D) Assay for D-dimer

Accepted Answer

The answer of What reflex test should be done on...

Question 23

What are the roles of thrombin in coagulation?

Accepted Answer

The answer of What are the roles of thrombin in...

Question 24

Which of the following is a role of thrombin?&#10;A) Activates anticoagulant (protein C)&#10;B) Increases fibrinolysis&#10;C) Inhibits endothelial cell release of tissue plasminogen activator&#10;D) Inhibits the formation of fibrin monomers

Accepted Answer

The answer of Which of the following is a role...

Question 25

What factor does the extrinsic pathway require that the intrinsic and common pathways do not?&#10;A) Vitamin K&#10;B) Zymogens&#10;C) Tissue factor&#10;D) tPA

Accepted Answer

The answer of What factor does the extrinsic pathway require...

Question 26

How does systemic fibrinolysis differ from physiologic fibrinolysis?&#10;A) Systemic produces rapid fibrinolysis, whereas physiologic produces adequate fibrinolysis.&#10;B) Systemic results from improper plasminogen activation, whereas physiologic results from proper plasminogen activation.&#10;C) Physiologic is naturally occurring, whereas systemic results from an external trigger.&#10;D) Physiologic is localized to the fibrin clot, whereas systemic results in circulating plasmin.

Accepted Answer

The answer of How does systemic fibrinolysis differ from physiologic...

Question 27

How do the following systems contribute to coagulation?&#10;a. Complement&#10;b. Fibrinolysis&#10;c. Kinin

Accepted Answer

The answer of How do the following systems contribute to...

Question 28

Interpret the following results: &#8226; Patient: 12-year-old boy with unexplained bruising, swollen knee joints, and prolonged bleeding from injuries&#10;&#8226; Screening tests:&#10;O PT = 12.2 sec (control: 11.5-13.3 sec)/INR: 1.09&#10;O APTT = 57 sec (control: 23-32 sec)&#10;O Bleeding time = 5 min (control: 2-10 min)&#10;Pending results from confirmation tests, this patient could be suffering from:&#10;A) An intrinsic pathway problem&#10;B) An extrinsic pathway problem&#10;C) A primary hemostasis problem&#10;D) A common pathway problem

Accepted Answer

The answer of Interpret the following results: &#8226; Patient: 12-year-old...

Question 29

Complete the following table by listing the coag factors in the Intrinsic, Extrinsic and Common Pathways using both the Factor designation and common name.&#10;

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The answer of Complete the following table by listing the...

Question 30

Which of the following is not a role of high molecular weight kininogen?&#10;A) Accelerate the rate of surface-dependent activation of F-XII&#10;B) Serves as a non-enzymatic cofactor in contact factor activation&#10;C) Provide bradykinin&#10;D) Accelerates the formation of Factor VIIa

Accepted Answer

The answer of Which of the following is not a...

Question 31

During activation of coagulation, all of the following bind to the phospholipid membrane surface forming a complex except:&#10;A) Procoagulant zymogen (substrate)&#10;B) Coagulation inhibitors&#10;C) Procoagulant cofactors&#10;D) Activated serine protease

Accepted Answer

The answer of During activation of coagulation, all of the...

Question 32

Fill in the missing factors in the traditional coagulation cascade:&#10;

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Question 33

Thrombin activatable fibrinolysis inhibitor (TAFI) is defined as a:&#10;A) Procoagulant&#10;B) Anticoagulant&#10;C) Profibrinolytic&#10;D) Antifibrinolytic

Accepted Answer

The answer of Thrombin activatable fibrinolysis inhibitor (TAFI) is defined...

Question 34

On which chromosome does the factor VIII locus reside?&#10;A) 3&#10;B) 4&#10;C) 11&#10;D) X

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The answer of On which chromosome does the factor VIII...

Question 35

Thrombin activity impacts coagulation by which of the following mechanism(s)?&#10;A) Altering blood flow&#10;B) Positive feedback only&#10;C) Negative feedback only&#10;D) Positive and negative feedback

Accepted Answer

The answer of Thrombin activity impacts coagulation by which of...

Deck 32: Secondary Hemostasis and Fibrinolysis