In general, when a bleed occurs, for example, when you sustain a paper cut, your body responds immediately by initiating what is called a coagulation cascade in order to form a clot at the site of bleeding, to stop bleeding. First,
platelets go to the area,
and release several substances including one particular substance called thromboxane, and other clotting factors are recruited to the area, a clot then a scab eventually forms. This process occurs everywhere in the body to stop a bleed.