16. Physiological hemostasis Flashcards
- Physiological hemostasis
Hemostasis
-complex process involving platelet activation and circulating clotting
factors
-physiological hemostasis
-artificial hemostasis
>temporary(provisional)
>definitive
Hemostasis(to stop bleeding)
-hemostasis–process that causes blood from escaping the damaged blood vessel
-the balance of anti-and procoagulants keeps the blood in liquid form
1.vascular spasm(verisuonen supistuminen,vähentää veren määrän tulemista vauriokohtaan)
2.platelet plug formation(verihiutaleiden tarttuu vauriokohtaan ja muodostaa tulpan)
3.clot formation(coagulation)(hyytyminen)
Hemostasis(simplified)
-injury→vasoconstrictors released from endothelium (endothelin)→vasoconstriction at the site→(aggregation and)adhesion of platelets(plug formation)
-thromboplastin(combination of phospholipids and tissue factor)catalyzes the conversion of prothrombin(nonactive) to thrombin→thrombin causes fibrinogen to polymerize→polymerized fibrin(glue) forms
long strands of tough unsoluble protein that are bound to the
platelets→formation of a hemostatic clot
A.vasoconstriction(endothelin release causes vasoconstriction)
B.primary hemostasis(1.platelet adhesion,2.shape change,3.granule release,4.recruitment,5.aggregation=hemostatic plug;collagen)
C.secondary hemostasis(1.tissue factor,2.phospholipid complex expression,3.thrombin activation,4.fibrin polymerization=fibrin)
D.thrombus and antithrombotic events(release of t-PA(fibrinolysis),thrombomodulin(blocks coagulation cascade),trapped neutrophil, trapped red blood cells, polymerized fibrin)
