The Coagulation System

Question 1

What are the three main stages to Haemostasis

Answer 1

1. Vascular Spasm
2. Platelet Activation and Plug Formation (Primary Haemostasis)
3. Coagulation (Secondary Haemostasis)

Question 2

What are the two storage granules found in platelets?

Answer 2

Alpha granules

Electron dense granules

Question 3

What is the extrinsic pathway triggered by?

Answer 3

Trauma to extra-vascular cells

Question 4

What is the intrinsic pathway triggered by?

Answer 4

Damaged blood vessels

Question 5

What is thrombocytopaenia? What is the definition of it

Answer 5

Low platelet count, <100,000 / ml of blood

Question 6

How is Glanzmann’s Thrombocytopenia caused?

Answer 6

Mutation leading to abnormal GPIIb / IIIa, affecting platelet aggregation

Question 7

What is the genetic basis of Haemophillia?

Answer 7

Recessive sex linked X-chromosome disorder

Question 8

What is the pharmacological basis of Aspirin’s activity?

Answer 8

COX 1 Irreversible Inhibitor

COX 2 activity modification

Question 9

What is the pharmacological basis of Clopidogrel?

Answer 9

ADP Receptor Antagonist

Question 10

Clopidogrel is a pro-drug. What does this mean?

Answer 10

It gets metabolized into it’s active form by hepatic CYP2C19 (a form of the P450 enzyme)

Question 11

State two anti-coagulant drugs

Answer 11

Warfarin

Heparin

Question 12

What is Warfarin?

Answer 12

Anticoagulant, Vitamin K antagonist. Many clotting factors reply on reduced Vit K