What are the four phases of wound healing?

• A. Hemostasis, inflammatory, proliferation, and maturation.
• B. Hemostasis, proliferation, migration, remodeling.
• C. Inflammation, proliferation, maturation, infection.
• D. Hemostasis, inflammation, infection, remodeling.

Answer: (A)

Wound healing progresses through four overlapping phases: hemostasis, inflammation, proliferation, and maturation (remodeling).

Right after injury, hemostasis kicks in to stop bleeding. Blood vessels constrict and platelets form a clot that provides a temporary matrix and releases growth factors to start repair.

The inflammatory phase follows, lasting several days. White blood cells, especially neutrophils and macrophages, clear debris and bacteria and release signals that recruit cells needed for tissue repair. This sets the stage for new tissue formation.

In the proliferative phase, new tissue is built. Fibroblasts lay down collagen and extracellular matrix, new blood vessels form (angiogenesis), granulation tissue fills the wound, and re-epithelialization covers the surface. Wound contraction may also occur as myofibroblasts help close the gap.

During maturation (remodeling), the newly formed tissue is reorganized and strengthened over time. Collagen is replaced and cross-linked, increasing tensile strength, though a fully healed scar is never as strong as unwounded skin. This phase can last weeks to months.

The other options mix phases or introduce concepts (like infection or migration) that aren’t recognized as separate phases in the standard sequence, so they don’t fit the established progression as well as the four listed.