1- Haemostatic Mechanism3

2- Thromboxane A2 (TXA2) is important in secondary amplification
of platelet activation to form a stable platelet aggregate.TXA2 not
only potentiates platelet aggregation, but also has powerful
vasoconstrictive activity.
3- The release reaction is inhibited by substance called prostacyclin
(PGI2),which is synthesized by vascular endothelial cells. It is a
potent inhibitor of platelet aggregation and prevents their deposition
on normal vascular endothelium.