coagulation and anticoagulation

Question 1

how is the extrinsic pathway activated?

Answer 1

a direct wound to the vascular wall

Question 2

how is the intrinsic pathway activated?

Answer 2

Blood interactions with a foreign substance

Question 3

What factors are involved in order

Answer 3

XII, XI, IX, VIIIa, X, Va

Question 4

where do factor VIII and V come from?

Answer 4

factor VIIIa is just in the blood floating around all the time i think and factor V is activated by thrombin to make factor Va

Question 5

What are the control points?

Answer 5

1. Calcium
2. Thrombin - key component in the coagulation cascade
3. Platelet adhesion - kick off the coagulation
4. Clotting factors

Question 6

why does controlling calcium stop coagulation and how do we control it?

Answer 6

Calcium is important in every stage of coagulation, without it blood would not clot.
We can use EDTA which binds to calcium and stops it from being in the bloodstream so therefore stops coagulation

Question 7

How can we use clotting factors to control coagulation?

Answer 7

factor V and factor VIII are good factors to block as they would stop the whole cascade

Question 8

How do glycocalyx mucopolysaccharides work?

Answer 8

Using the fact that several steps of coagulation happen on the surface of an activated membrane protein which means that without it coagulation wouldn’t happen. Glycocalyx mucopolysaccharide repels clotting factors and adhering proteins on blood contacting surfaces of the endothelium. This means that platelets wouldn’t attach

Question 9

Thrombin anticoagulants

Answer 9

• thrombomodulin binds to thrombin making its unavailable to the cascade
• the thrombin-thrombomodulin complex makes factor C which inactivates factors Va and VIIIa

Question 10

Fibrin Anticoagulants

Answer 10

fibrin binds to 85-90% of thrombin formed during coagulation. Antithrombin III binds and inactivates much of the rest of the non-absorbed thrombin

Question 11

What is Fibrinolysis? What Chemical does it and how is it done?

Answer 11

the breaking down of blood clots, plasminogen is trapped in the blood clot during coagulation. tPA converts plasminogen into plasmin which cleaves peptide bonds which degrade the clot

Question 12

How might all of this affect the function of a biomaterial?

Answer 12

Blood clots might break away and block arteries etc or you can get tissue growth called intimal hyperplasia which causes the narrowing of the blood vessels

Question 13

What is intimal hyperplasia?

Answer 13

tissue growth in the arteries that causes the narrowing of the blood vessels