ANP 1105 Lecture 10: Lecture 10 Anatomy

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Balwant Tuana

Document Summary

Hemostasis comes in three phases: vasoconstriction, platelet aggregation, blood clot-coagulation. The primary platelet plug is fragile and can easily be dislodged from the vessel wall. Begins 10-20 seconds after vascular injury and platelet adhesion. Requires dense granule release from the adhering platelets. Requires brinogen and brinogen receptors gpllb and llla. Adp released from platelet cytoplasm upon adherence induces exposure of brinogen receptors gpllb and llla. Fibrinogen binds to the exposed gpllb and llla. Extracellular calcium ion-dependent brinogen bridges form between adjacent platelets, thereby promoting platelet aggregation. Secondary aggregation begins the release of dense granules. Secondary aggregation begins with platelet secretion of dense granules. Adp binds to the platelet membrane, triggering the synthesis and release of txa2. The release of large amounts of adp combined with txa2 ampli es the initial aggregation of platelets into a large platelet mass. * differentiate between the intrinsic and extrinsic pathways for the formation of prothrombin activator.