hemostasis

• Clot formation


  1. Platelets recruited to site of vessel injury

  2. Platelets linked to collagen via receptor

  3. Platelet shape change to dendritic form

  4. Activated platelets release prothrombotic molecules

  5. ADP induces platelet aggregation

  6. Thromboxane mediates platelet activation and aggregation

  7. Platelets cross-link

  8. Activated platelets trigger coagulation cascade

  9. Thrombin stimulates further platelet activation

  10. Thrombin induces fibrin formation
• von Willebrand factor


  Mediates linking of platelets to collagen
• ADP


  Prothrombotic molecule released by activated platelets
• Thromboxane


  Important mediator of platelet activation and aggregation
• Thrombin


  Stimulates platelet activation, induces fibrin formation
• Platelet activation


  Triggers coagulation cascade
• Platelet activation and aggregation


  Self-reinforcing process crucial in blood clot formation
• The self-reinforcing process of platelet activation is an obvious therapeutic target in conditions caused by an appropriately triggered blood coagulation
• Coagulation cascade activation


  1. Extrinsic pathway activation

  2. Intrinsic pathway activation
• Extrinsic pathway activation


  Begins with now exposed molecules of the vessel wall such as tissue factor which forms a complex with factor 7 finally leading to the activation of factor 10
• Intrinsic pathway


  Consists of various coagulation factors activating each other in a chain reaction at it set a complex with an additional cofactor is formed this complex now activate factor 10
• Factor 10a


  • The point at which the extrinsic and the intrinsic pathways of the coagulation cascade meet
  • Has a pivotal role in the coagulation cascade
  • In combination with 5a activate thrombin and induces the so-called thrombin birth
  • One molecule of factor 10a can catalyze the formation of a thousand molecules of thrombin
• Thrombin formation


  1. Factor 10a and 5a activate thrombin

  2. Thrombin causes further activation of platelets and enhanced formation of fibrin
• Fibrin


  Forms strands making up the mesh that stabilizes the platelet plug in an arterial clot and holds together the red blood cells in a venous clot
• The central role of factor 10a in the coagulation cascade makes it a viable target for therapeutic intervention in pathologically altered blood coagulation