Earliest event of vascular trauma is?
Ans. (a) Vasoconstriction(Ref: Robbins 9th/pg 661)Endothelial Injury causes vasoconstriction Q (due to endothelin, serotonin) immediately and markedly reduces blood flow to the injured area.
Vasoconstriction
Platelet adhesion
Platelet aggregation
Vasodilatation
Bleeding Disorders