🩹 Coagulation and Hemostasis Review for the MedTech Board Exam

What the Coagulation course covers

1. Unit 1: Platelets

   Platelet structure, how a platelet plug forms, platelet production and platelet tests.

   Platelet structure · Building the platelet plug · Platelet production · Platelet tests

2. Unit 2: Too Few or Too Many Platelets

   Thrombocytopenia, immune platelet destruction, TTP, HIT and thrombocytosis.

   Why platelets fall · Immune destruction & TTP · HIT & thrombocytosis

3. Unit 3: Platelet Function Disorders

   Inherited membrane and granule defects, and acquired platelet dysfunction.

   Membrane defects · Granule & secretion defects · Acquired platelet dysfunction

4. Unit 4: The Coagulation Cascade

   Clotting factors, the intrinsic, extrinsic and common pathways, and fibrin formation.

   Meet the factors · Intrinsic & extrinsic pathways · Common pathway & thrombin · Fibrin & factor XIII

5. Unit 5: Keeping Clotting in Check

   Vitamin K and warfarin, natural anticoagulants, fibrinolysis and the vessel wall.

   Vitamin K & warfarin · Natural anticoagulants · Fibrinolysis · The vessel wall

6. Unit 6: Coagulation Testing

   Specimen rules, PT/INR, APTT, thrombin time, mixing studies and special assays.

   The coag specimen · PT & INR · APTT, thrombin time & fibrinogen · Mixing studies & factor assays · Fibrinolysis & thrombophilia tests

7. Unit 7: Inherited Bleeding Disorders

   Hemophilia A and B, von Willebrand disease and the rarer factor deficiencies.

   Hemophilia A & B · von Willebrand disease · Rare factor deficiencies

8. Unit 8: Acquired Disorders & Thrombosis

   DIC, liver disease, anticoagulant drugs, inhibitors and inherited clotting tendencies.

   DIC, fibrinolysis & liver disease · Anticoagulants & inhibitors · Thrombophilia

Sample Coagulation board exam questions

A few practice questions from the course, with explanations. Thousands more are in the app.

1. 1. Platelet adhesion to collagen under high shear needs:

   1. von Willebrand factor and GP Ib/IX/V
   2. Calcium alone
   3. Factor VIII
   4. Fibrinogen and GP IIb/IIIa
   Show answer

   Answer: A. von Willebrand factor and GP Ib/IX/V

   Under high shear (arteries, small vessels), platelets cannot grab collagen fast enough on their own. vWF binds exposed collagen and stretches out, and platelet GP Ib/IX/V catches it like velcro. Fibrinogen and GP IIb/IIIa act later, in aggregation.

2. 2. TTP is caused by:

   1. Severe ADAMTS13 deficiency, usually from an autoantibody
   2. A factor VIII inhibitor
   3. Antiplatelet IgG
   4. E. coli toxin
   Show answer

   Answer: A. Severe ADAMTS13 deficiency, usually from an autoantibody

   ADAMTS13 normally cuts ultra-large vWF multimers. When an IgG autoantibody blocks it (or, rarely, it is inherited low), the giant multimers catch platelets in small vessels. Activity below 10% supports TTP.

3. 3. Bernard–Soulier syndrome shows:

   1. Giant platelets and no ristocetin aggregation that normal plasma does not fix
   2. Normal-sized platelets
   3. Gray platelets
   4. Absent GP IIb/IIIa
   Show answer

   Answer: A. Giant platelets and no ristocetin aggregation that normal plasma does not fix

   Bernard–Soulier lacks GP Ib/IX/V, the vWF receptor. Ristocetin cannot make platelets stick, and adding normal plasma (with vWF) does not help because the defect is on the platelet. Platelets are large and the count is mildly low.

4. 4. Coagulation starts in the body when factor VII binds:

   1. Kallikrein
   2. HMWK
   3. Factor XII
   4. Tissue factor
   Show answer

   Answer: D. Tissue factor

   Injury exposes tissue factor on cells outside vessels. Factor VII binds it, becomes VIIa, and the TF–VIIa complex activates factors X and IX. This extrinsic (tissue factor) pathway is how clotting begins in the body.

5. 5. The vitamin K-dependent factors are:

   1. I and XIII
   2. XI and XII
   3. II, VII, IX and X (and proteins C and S)
   4. V and VIII
   Show answer

   Answer: C. II, VII, IX and X (and proteins C and S)

   The liver adds a carboxyl group to glutamic acids on II, VII, IX and X (and proteins C and S) using vitamin K. These γ-carboxy groups bind calcium, letting the factors attach to phospholipid. Without vitamin K, the factors do not work.

6. 6. The blood-to-citrate ratio for coagulation tests is:

   1. 1:1
   2. 4:1
   3. 20:1
   4. 9:1 with 3.2% sodium citrate
   Show answer

   Answer: D. 9:1 with 3.2% sodium citrate

   Light blue tubes contain 3.2% sodium citrate, and 9 parts blood to 1 part citrate is the standard ratio. Citrate binds calcium; the test adds calcium back in a fixed amount. A wrong ratio changes the results.

7. 7. Hemophilia A shows:

   1. Low platelets
   2. A long PT
   3. X-linked bleeding, long APTT, low factor VIII, normal PT and platelets
   4. Autosomal inheritance
   Show answer

   Answer: C. X-linked bleeding, long APTT, low factor VIII, normal PT and platelets

   Hemophilia A is X-linked recessive, so mostly males are affected and females are carriers. Factor VIII is in the intrinsic pathway: APTT long, PT and platelet count normal. Bleeding is into joints and muscles, not petechiae.

8. 8. DIC typically shows:

   1. Normal D-dimer
   2. Low platelets and fibrinogen, long PT and APTT, high D-dimer
   3. High fibrinogen
   4. Normal PT
   Show answer

   Answer: B. Low platelets and fibrinogen, long PT and APTT, high D-dimer

   In DIC, widespread clotting uses up platelets and fibrinogen and other factors, so PT and APTT lengthen. Fibrinolysis breaks down the clots, so D-dimer is high. Schistocytes may appear on the smear.

Practice more Coagulation questions

How you review in MedTech Reviewer

• Learning path: short lessons, each followed by questions, with a checkpoint at the end of every unit.
• Spaced repetition: questions you miss come back sooner, so key facts stick for exam day.
• Flashcards and timed quizzes in exam style, with an explanation for every answer.
• Board-readiness score per subject, so you know where to focus.
• Arcade games, PvP battles and Guilds to keep reviewing fun with classmates.

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