Events Of Hemostasis

Question 1

First step

Answer 1

Vascular spasm or vasoconstriction: reduction of blood flow by vasoconstriction 
Caused by
Nervous reflexes
Local myogenic reflexes
Humoral factors

Question 2

Second step

Answer 2

Formation of platelet plug
Sealed by platelet plug
Injury to blood vessel-> platelet adhesion-> platelet activation-> release of platelet contents-> platelet aggregation-> platelet plug formation

Question 3

Third step

Answer 3

For severe trauma

Shedding of blood-> coagulation-> fibrin-> clot-> hemostasis

Question 4

Fourth step

Answer 4

After clot formation, it is invaded by fibroblasts or it dissolves. They are formed within few hours following clot formation. Later after 2 weeks the clot is organised into fibrous tissue.
Clot is dissolved by action of special enzymes. Occurs where there is no requirement of clot formation