The blood does not clot inside the body due to anti-coagulants. Why does it clot outside the body? For example; when the blood is taken in a tube, it clots after some time, why?
Yes, a deficiency of anti-coagulants can be the reason. But what actually happens outside the body to clot the blood because there is no specific mechanism which can be found inside the body to clot the blood on injured parts?