- Arteriolar vasoconstriction
- Reflex neurogenic mechanisms
- Local secretion of vasoconstrictive factors (endothelin)
- Primary haemostasis - initiation and formation of a platelet plug
- Formation of the platelet plug
- vWF and collagen exposed
- Platelet activation and change in morphology with secretion of granules
- Platelet aggregation
- Secondary haemostasis - Propagation of clotting through the coagulation cascade.
- Deposition of fibrin
- Tissue factor and collagen exposed; activation of factor VII(a), cascade towards Thrombin formation to mature fibrin.
- Consolidates the platelet plug
- Clot stabilisation
- Polymerized fibrin and aggregated platelets contract to form a permanent plug
- Re-absorption
- Termination of clotting through anti-thrombotic control mechanisms
- Counter-regulatory mechanisms are set into motion to limit VTE
- t-PA etc eventually resorb clot
