During which phase of wound healing do blood vessels constrict and platelets aggregate to form a clot?

• A. Inflammation
• B. Proliferation
• C. Hemostasis
• D. Maturation

Answer: (C)

The phase of wound healing characterized by blood vessel constriction and platelet aggregation leading to clot formation is hemostasis. This is the immediate response following injury, where the body initiates a series of events to control bleeding and create a stable scaffold from which healing can proceed.

During hemostasis, when a blood vessel is damaged, vascular spasm occurs, causing the blood vessels to constrict (vasoconstriction), which helps minimize blood loss. This is followed by platelet adhesion to the exposed collagen fibers at the injury site, leading to platelet activation and aggregation. The aggregated platelets release several mediators that contribute to further platelet recruitment and activate the coagulation cascade, ultimately forming a fibrin clot that stabilizes the area and provides an initial matrix for subsequent phases of healing.

The inflammation phase follows hemostasis and is characterized by the infiltration of immune cells to clean up the area and prevent infection. The proliferation phase involves tissue formation and repair, primarily focusing on collagen deposition and re-epithelialization. Maturation, or remodeling, is the final phase where the tissue matures and strengthens over time.

Thus, hemostasis is crucial as it is the first response in wound healing, providing the necessary conditions for the subsequent healing processes