Which statement is accurate about the first-phase wound healing processes?

• A. The first phase involves vasoconstriction, platelet aggregation, and fibrin formation
• B. The first phase is defined by granulation tissue formation
• C. The first phase is characterized by epithelialization only
• D. The first phase occurs days after injury

Answer: (A)

The first phase of wound healing is the immediate hemostatic response that sets up the wound for healing. Right after injury, blood vessels constrict to limit bleeding, then platelets are recruited and aggregate to form a plug. The coagulation system activates to form a fibrin clot, which stabilizes the wound and provides a scaffold for inflammatory cells to arrive. This sequence—vasoconstriction, platelet aggregation, and fibrin formation—defines the initial phase.

Granulation tissue formation and epithelialization are part of later stages, not the first phase. Epithelialization happens as keratinocytes migrate to restore the epidermis, and granulation tissue forms during the proliferative phase as new connective tissue and blood vessels rebuild the wound bed. The first phase occurs promptly, not days after injury.