How long does vascular spasm typically last?

1. Vascular spasm must hold long enough for the slower repairs to be built. 2. The extrinsic coagulation pathway completes in seconds and the intrinsic pathway in a few minutes. 3. A spasm lasting only 30 seconds would therefore expire before the clot was stabilised. 4. The spasm typically lasts up to 30 minutes, and it can last for hours. 5. That duration comfortably covers both coagulation pathways and the retraction of the clot. 6. The shorter options are all plausible on instinct but fail this timing check against the cascade. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.5 Hemostasis_