Final answer:
The fast series of reactions to stop bleeding is called hemostasis. Hemostasis involves three basic steps: vascular spasm, the formation of a platelet plug, and coagulation. During coagulation, a blood clot is formed to seal the wound and stop the bleeding.
Step-by-step explanation:
The fast series of reactions to stop bleeding is called hemostasis. Hemostasis is the physiological process by which bleeding ceases. It involves three basic steps: vascular spasm, the formation of a platelet plug, and coagulation. During coagulation, a blood clot is formed to seal the wound and stop the bleeding.