21. Anticoagulants

Question 1

describe haemostasis?

Answer 1

Essential for life
Limits bleeding following injury – adhesion and activation of platelets and fibrin formation
haemostatic plug + fibrin mesh → stable bleeding control

Question 2

define thrombosis

Answer 2

pathological haemostasis – in the absence of bleeding things gone wrong

Question 3

give 4 examples of Thromboembolic diseases

Answer 3

• deep vein thrombosis (DVT) and pulmonary embolism (PE)
• transient ischaemic attacks (TIA), ischaemic stroke
• myocardial infarction (MI)
• consequence of atrial fibrillation (AF)

Question 4

compare Venous and intracardiac thrombosis to arterial thrombosis

Answer 4

Venous and intracardiac thrombosis driven largely by coagulation cascade and fibrin

arterial thrombus - mainly platelet rich

Question 5

role of Anticoagulant drugs?

Answer 5

Prevent thrombus formation and thrombus growing

Question 6

What is the intrinsic pathway?

Answer 6

Factors found in blood begin cascade (exposed collagen):

XII → XI → IX → X → II → I (fibrinogen)

Question 7

What is the extrinsic pathway?

Answer 7

Activated by tissue factor (factor III) released by endothelial cells:
VII → X → II → I

Question 8

How are coagulation factors present in the blood?

Answer 8

Present as inactive zymogens

Question 9

why is regulation of the coagulation cascade essential?

Answer 9

to prevent solidification of all blood