Final answer:
The intrinsic pathway involves more steps and takes more time, around 5 minutes, to complete compared to the extrinsic pathway which takes seconds. This complexity is due to the activation of multiple clotting factors within the bloodstream before conversion into the common pathway where fibrin is produced.
Step-by-step explanation:
The clotting pathway that involves more steps and takes approximately 5 minutes is the intrinsic pathway. This pathway, triggered by internal damage to the blood vessel wall, is part of the clotting process working within the bloodstream. In contrast, the extrinsic pathway is faster and is activated by external trauma to the tissues surrounding the blood vessels, completing its course in seconds. Although both pathways ultimately converge into the common pathway, the intrinsic pathway is complex and includes multiple clotting factors derived from the bloodstream itself or secreted by the liver and platelets, such as Ca2+ and vitamin K.
The process initiates when factor XII is activated, which then sets off a chain reaction involving several other clotting factors like XI, IX, and VIII, before joining the common pathway. It is within this common pathway that fibrin is synthesized, an essential step for the formation of a durable blood clot.