Regulation & Measurement Of Haemostasis

Question 1

How is the formation of a primary haemostatic plug prevented from uninjured vessels?

Answer 1

The intact endothelium releases factors such Nitric Oxide(NO) and Prostacyclin that inhibits platelet aggregation

Question 2

How is the clot confined to one injured area only?

Answer 2

PLASMIN released via activation of plasminogen by tissue plasminogen activator(tPA)
THROMBOMODULIN-blocks coagulation cascade

Question 3

How is the coagulation cascade limited?

Answer 3

*THROMBOMODULIN binds to thrombin,this complex inhibits factors 5a and 8a by activating PROTEIN C(works along with ProteinS)

*ANTITHROMBIN-inhibits thrombin and 10a

*TISSUE FACTOR PATHWAY INHIBITOR(TFPI)-inhibits interaction of 10a with TF-7a complex

Question 4

How is the fibrinolytic system system regulates i.e makes sure the plug stats intact

Answer 4

*ALPHA-ANTIPLASMIN binds to PLASMIN and inhibits it.
*Plasminogen activator inhibitor inhibit tPA