Secondary Hemostasis

Question 1

What is Factor I?

Answer 1

Fibrinogen – the final substrate in clot formation.

Question 2

What is Factor II?

Answer 2

Prothrombin – converted to thrombin during clotting.

Question 3

What is Factor III?

Answer 3

Tissue thromboplastin (Tissue Factor) – initiates the extrinsic pathway.

Question 4

What is Factor IV?

Answer 4

Calcium (Ca²⁺) – required for coagulation complex formation.

Question 5

What is Factor V?

Answer 5

Cofactor to Factor Xa in the prothrombinase complex.

Question 6

What is Factor VII?

Answer 6

Proconvertin – participates in the extrinsic pathway.

Question 7

What is Factor VIII?

Answer 7

Anti-hemophilic factor A – cofactor for Factor IX in intrinsic pathway.

Question 8

What is Factor IX?

Answer 8

Anti-hemophilic factor B (Christmas Factor) – activates Factor X.

Question 9

What is Factor X?

Answer 9

Stuart-Prower factor – activates prothrombin to thrombin.

Question 10

What is Factor XI?

Answer 10

Plasma thromboplastin antecedent – activates Factor IX.

Question 11

What is Factor XII?

Answer 11

Hageman factor – initiates the intrinsic pathway.

Question 12

What is Factor XIII?

Answer 12

Fibrin-stabilizing factor – cross-links fibrin to strengthen the clot.

Question 13

What are the three coagulation pathways?

Answer 13

Intrinsic, extrinsic, and common pathways.

Question 14

What triggers the extrinsic pathway?

Answer 14

Tissue Factor (Factor III) exposure.

Question 15

What triggers the intrinsic pathway?

Answer 15

Contact with negatively charged surfaces (e.g., damaged vessel walls).

Question 16

What is the common pathway’s final step?

Answer 16

Thrombin converts fibrinogen to fibrin.

Question 17

What factors are unique to the intrinsic pathway?

Answer 17

Factors XII, XI, IX, and VIII.

Question 18

What factors are unique to the extrinsic pathway?

Answer 18

Factor VII and Tissue Factor (III).

Question 19

What factors are part of the common pathway?

Answer 19

Factors X, V, II (prothrombin), and I (fibrinogen).

Question 20

What is thrombin’s role in coagulation?

Answer 20

It converts fibrinogen to fibrin and activates platelets.

Question 21

Which coagulation factors are Vitamin K-dependent?

Answer 21

Factors II, VII, IX, and X.

Question 22

How does Vitamin K deficiency affect clotting?

Answer 22

It leads to defective clotting due to nonfunctional factors.

Question 23

What drug inhibits Vitamin K recycling?

Answer 23

Warfarin (Coumadin).

Question 24

What is the role of platelets in coagulation?

Answer 24

They provide a surface for clotting factor assembly.

Question 25

What is platelet factor 3 (PF3)?

Answer 25

A phospholipid surface aiding coagulation.

Question 26

What is the role of von Willebrand Factor (VWF)?

Answer 26

It stabilizes Factor VIII and aids platelet adhesion.

Question 27

What disorder results from VWF deficiency?

Answer 27

Von Willebrand Disease (VWD).

Question 28

What is the function of Protein C?

Answer 28

It inactivates Factors Va and VIIIa.

Question 29

What is the role of Protein S?

Answer 29

It acts as a cofactor for Protein C.

Question 30

What is the function of Antithrombin (AT)?

Answer 30

It inhibits thrombin and Factor Xa.

Question 31

What is Tissue Factor Pathway Inhibitor (TFPI)?

Answer 31

It inhibits Factor VIIa and the tissue factor complex.

Question 32

What enzyme breaks down fibrin clots?

Answer 32

Plasmin.

Question 33

What is the inactive form of plasmin?

Answer 33

Plasminogen.

Question 34

What activates plasminogen to plasmin?

Answer 34

Tissue plasminogen activator (TPA) and urokinase.

Question 35

What is the function of α2-antiplasmin?

Answer 35

It inhibits plasmin to prevent excessive clot breakdown.

Question 36

What are fibrin degradation products (FDPs)?

Answer 36

Fragments of fibrin after plasmin digestion.

Question 37

What is D-dimer?

Answer 37

A marker of fibrinolysis, indicating cross-linked fibrin breakdown.

Question 38

What clinical conditions elevate D-dimer?

Answer 38

Deep vein thrombosis (DVT), pulmonary embolism (PE), and disseminated intravascular coagulation (DIC).

Question 39

What factor deficiency causes Hemophilia A?

Answer 39

Factor VIII deficiency.

Question 40

What factor deficiency causes Hemophilia B?

Answer 40

Factor IX deficiency.

Question 41

What factor deficiency causes Hemophilia C?

Answer 41

Factor XI deficiency.

Question 42

What is Disseminated Intravascular Coagulation (DIC)?

Answer 42

A condition with widespread clotting and fibrinolysis leading to bleeding.

Question 43

What lab tests diagnose coagulation disorders?

Answer 43

Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), and D-dimer tests.

Question 44

What does a prolonged PT indicate?

Answer 44

Deficiency in the extrinsic pathway (e.g., Factor VII deficiency).

Question 45

What does a prolonged APTT indicate?

Answer 45

Deficiency in the intrinsic pathway (e.g., Factor VIII or IX deficiency).

Question 46

What test is used to monitor Warfarin therapy?

Answer 46

Prothrombin Time (PT) / INR.

Question 47

What test is used to monitor Heparin therapy?

Answer 47

Activated Partial Thromboplastin Time (APTT).

Question 48

What is the main treatment for Hemophilia A?

Answer 48

Factor VIII replacement therapy.

Question 49

What is the main treatment for Hemophilia B?

Answer 49

Factor IX replacement therapy.

Question 50

How is fibrinolysis controlled in patients with excessive bleeding?

Answer 50

Using antifibrinolytic agents like tranexamic acid.