Major in vivo pathway of coagulation -

Ans. is 'c' i.e., Extrinsic pathwayo Blood coagulation pathways are divided into :-i) Intrinsic pathway (contact pathway): It is largely an 'in vitro' pathway and is activated when factor XII (Hageman factor or contact factor) comes in contact with negatively charged surface, e.g. glass, kaolin etc.ii) Extrinsic pathway: It is largely an in vivo pathway is activated by tissue factor (thromboplastin) at the site of tissue injury.