PHYSIOLOGY OF HAEMOSTASIS & BASIC LABORATORY INVESTIGATIONS

1. One of the element to ensure haemostasis process is working is

• A. presence of thrombopoietin in circulation.
• B. good networking of red and white blood cell.
• C. presence of adequate number of platelets.
• D. adequate number of vascular endothelial cells.
• E. reconnection of lymphatic vessel to blood vessel.

2. Choose the CORRECT statements regarding endothelial cells.

• A. They produce tissue factor (TF).

• B. They provide collagen to subendothelial layer.

• C. They secrete thrombopoietin.

• D. They stores von Willebrand factor (vWF).

3. The objective/function/role of primary haemostasis is to

• A. build a cholesterol plaque.
• B. build unstable platelet plug.
• C. produce a fibrin clot.
• D. produce unstable fibrin clot.
• E. provide coverage to endothelial cells.

4. Select the CORRECT statements regarding secondary haemostasis.

• A. Crosslinked fibrin is the final product.

• B. Factor XIIa has a major role in fibrin formation.

• C. It is initiated by tissue factor (TF)-FVIIa complex.

• D. It produces little amount of plasmin.

5. One of the natural inhibitor of coagulation is

• A. plasminogen.
• B. anti thrombin.
• C. factor VIIa.
• D. fibrin.
• E. warfarin.

6. Identify CORRECT PREANALYTICAL variables for coagulation test from the list below.

• A. Blood collection by experienced phlebotomist.

• B. Expired reagents should not be used.

• C. Shipment of blood sample for coagulation in ice.

• D. Sodium citrate anticoagulant tube is used for clotting test.

7. Screening test for investigation of suspected platelet disorder is

• A. Bone marrow aspirates and trephine examination.
• B. Peripheral blood film.
• C. Platelet aggregation study.
• D. Platelet electron microscopy.
• E. Platelet flowcytometry.

8. Identify the CORRECT MATCH for coagulation screening tests.

• A. Activated partial thromboplastin time (aPTT)-efficiency of intrinsic system.

• B. D-Dimer-integrity of fibrinogen.

• C. Prothrombin time (PT)-efficiency of extrinsic system.

• D. Thrombin time- integrity of fibrinolysis system.

9. Coagulation mixing test is performed when

• A. fibrinogen level is elevated/increased.
• B. isolated prolongation of aPTT is documented.
• C. megakaryocyte number is reduced in bone marrow aspirate.
• D. platelet count is low.
• E. thrombin time is prolonged.

10. Select the CORRECT MATCH for the coagulation tests abnormalities.

• A. Increased D-dimer level- disseminated intravascular coagulation (DIC).

• B. Prolonged aPTT- FVII deficiency.

• C. Prolonged PT- Haemophilia.

• D. Prolonged TT- Heparin therapy.