<prompt> All of the following are true about blood coagulation, exceptFactor X is part of both intristic and extrinsic path waysExtrinsic pathway is activatied by contact with negatively charged surfacesIntrinsic pathway can be activated in vitroCalcium is required in several steps of coagulation  <response>: harshmohan textbook of pathology 7 th edition extrinsic pathway is activated only by tissue damage which causes release of thromboplastin where as intrinsic pathway is activated by surface contact. factor x is a part of common pathway. Ca2 is required for conversion of 1x -1xa ,prothrombin to thrombin 