Hemostasis and Blood Clotting Quiz Part 1

Hemostasis and Blood Clotting Quiz Part One: Simple MCQs 1. What is the normal platelet count range per mm3 of blood? ○ (A) 50,000 to 100,000 ○ (B) 100,000 to 200,000 ○ (C) 150,000 to 400,000 ○ (D) 400,000 to 500,000 2. Which of the following is NOT a function of platelets? ○ (A) Release of vasoconstricting substances ○ (B) Formation of the primary hemostatic plug ○ (C) Production of red blood cells ○ (D) Release of platelet phospholipids for blood clotting 3. What is the primary role of hemostasis? ○ (A) To increase blood flow ○ (B) To prevent blood clotting ○ (C) To arrest bleeding from injured blood vessels ○ (D) To transport oxygen 4. Which of the following is the first step in hemostasis? ○ (A) Blood clot formation ○ (B) Platelet plug formation ○ (C) Vascular spasm ○ (D) Fibrosis 5. What is the mechanism behind the myogenic response in vascular spasm? ○ (A) Pain reflex causing vasoconstriction ○ (B) Release of chemical substances ○ (C) Direct damage to smooth muscle causing contraction ○ (D) Activation of platelets 6. Which substance inhibits platelet activation and aggregation? ○ (A) Thromboxane A2 ○ (B) Serotonin ○ (C) Aspirin ○ (D) Calcium 7. Which vitamin is essential for the liver's production of several clotting factors? ○ (A) Vitamin A ○ (B) Vitamin B12 ○ (C) Vitamin C ○ (D) Vitamin K 8. What is the role of prothrombin activators in blood clot formation? ○ (A) Convert fibrinogen to fibrin ○ (B) Convert prothrombin to thrombin ○ (C) Activate platelets ○ (D) Inhibit clotting 9. Which of the following is NOT a natural anticoagulant? ○ (A) Heparin ○ (B) Antithrombin III ○ (C) Thrombin ○ (D) Protein C 10. What is the function of plasmin in the fibrinolytic system? ○ (A) Activates plasminogen ○ (B) Digests fibrin threads and other clotting factors ○ (C) Inhibits fibrinolysis ○ (D) Promotes clot formation Part Two: Complex MCQs 11. A patient presents with prolonged bleeding time and normal clotting time. Which of the following conditions is most likely? ○ (A) Hemophilia ○ (B) Purpura ○ (C) Vitamin K deficiency ○ (D) Deep vein thrombosis 12. How does aspirin affect hemostasis? ○ (A) Promotes platelet aggregation ○ (B) Inhibits thromboxane A2 formation, reducing platelet activation ○ (C) Enhances fibrin formation ○ (D) Activates the intrinsic clotting pathway 13. Which of the following statements about clot retraction is FALSE? ○ (A) It involves the contraction of the blood clot. ○ (B) Platelets play a crucial role in clot retraction ○ (C) Serum is formed as a result of clot retraction ○ (D) Clot retraction occurs immediately after clot formation 14. The extrinsic pathway of blood coagulation is initiated by: ○ (A) Contact activation of Factor XII ○ (B) Release of tissue thromboplastin ○ (C) Exposure of blood to collagen ○ (D) Activation of Factor XI 15. Hemophilia A is characterized by a deficiency in which clotting factor? ○ (A) Factor VIII ○ (B) Factor IX ○ (C) Factor X ○ (D) Factor XI 16. Which natural anticoagulant mechanism primarily prevents clot formation on the endothelial surface? ○ (A) Smoothness of the endothelial surface and glycocalyx layer ○ (B) Antithrombin action of fibrin ○ (C) Heparin binding to antithrombin III ○ (D) Rapid blood flow 17. What is the clinical significance of the fibrinolytic system? ○ (A) It promotes the spread of blood clots ○ (B) It helps reopen blocked blood vessels and prevents excessive clotting ○ (C) It initiates the intrinsic clotting pathway ○ (D) It is responsible for the formation of the primary hemostatic plug 18. Which of the following is a potential consequence of endothelial damage? ○ (A) Increased production of prostacyclin ○ (B) Enhanced antithrombin activity ○ (C) Activation of the intrinsic clotting mechanism ○ (D) Prevention of platelet adhesion 19. What is the primary function of thrombodulin in the endothelium? ○ (A) Activates Factor V and VIII ○ (B) Inhibits platelet aggregation ○ (C) Binds with thrombin to inactivate clotting factors ○ (D) Promotes fibrinolysis 20. A patient with liver disease might experience bleeding tendencies due to: ○ (A) Impaired production of clotting factors ○ (B) Increased platelet aggregation ○ (C) Excessive fibrinolysis ○ (D) Enhanced vascular spasm 21. Which of the following best describes disseminated intravascular coagulation (DIC)? ○ (A) Formation of a stable clot at the site of injury ○ (B) Excessive clotting and bleeding due to the consumption of clotting factors ○ (C) Deficiency in a specific clotting factor ○ (D) Inability of platelets to aggregate 22. In the intrinsic pathway of coagulation, which factor is activated first? ○ (A) Factor X ○ (B) Factor IX ○ (C) Factor XII ○ (D) Factor XI 23. What is the role of calcium ions in the coagulation cascade? ○ (A) They are required for all steps of the cascade ○ (B) They are only involved in the extrinsic pathway ○ (C) They are involved in most steps, except for the first two in the intrinsic pathway ○ (D) They inhibit coagulation 24. Which of the following is true regarding the comparison between purpura and hemophilia? ○ (A) Both conditions result in prolonged clotting time ○ (B) Purpura is characterized by a deficiency in clotting factors, while hemophilia is caused by low platelet count ○ (C) Hemophilia is a congenital disorder, while purpura can be acquired ○ (D) Both conditions are equally common in males and females 25. The process of fibrinolysis is primarily mediated by: ○ (A) Thrombin ○ (B) Plasmin ○ (C) Factor XIII ○ (D) Tissue plasminogen activator (t-PA) inhibitor