Which sequence describes the steps of blood coagulation?

Which sequence describes the steps of blood coagulation?

• A. Oxygen transport by red blood cells.
• B. Vascular spasm, platelet plug formation, and coagulation phase.
• C. Antibody production by plasma cells.
• D. Neural reflexes causing vessel dilation.

Answer: (B)

Hemostasis occurs in a coordinated sequence to stop bleeding: a brief vascular spasm reduces blood flow, followed by platelet plug formation to seal the small break, and then the coagulation phase where a cascade of clotting factors converts fibrinogen into fibrin to stabilize the clot. This sequence—vasoconstriction, platelet plug, then coagulation—is the best description of how blood clots form. The other options describe unrelated processes: oxygen transport by red blood cells, antibody production by plasma cells, and neural reflexes causing vessel dilation, none of which capture the clotting sequence.

Hemostasis occurs in a coordinated sequence to stop bleeding: a brief vascular spasm reduces blood flow, followed by platelet plug formation to seal the small break, and then the coagulation phase where a cascade of clotting factors converts fibrinogen into fibrin to stabilize the clot. This sequence—vasoconstriction, platelet plug, then coagulation—is the best description of how blood clots form. The other options describe unrelated processes: oxygen transport by red blood cells, antibody production by plasma cells, and neural reflexes causing vessel dilation, none of which capture the clotting sequence.