Zusammenfassung der Ressource
Hemostasis
- Blood vessel ruptures
- 1).Vascular spasm
- The smooth muscle layer constricts
- 2).Platelet plug formation
- Platelets attach to exposed collagen fibres
- Release substances that promotes platelet aggregation
- Coagulation
- The intrinsic mechanism
- Initiated by contact with exposed the exposed collagen
- Activated simultaneously
- Prothrombin activator is formed
- Converted into thrombin
- Forms long threads of fibrin
- Surrounds the platelets and creates the framework
- RBC become trapped in the framework
- Platelets contract and clot retracts
- Blood vessel repairs
- Plasmin destroys fibrin network
- Fluidity of the plasma is restored
- The extrinsic mechanism
- Damaged tissue releases tissue thromboplastin and activates this mechanism
- Both mechanisms are activated simultaneously