All of the following statements regarding the inflammatory phase of wound healing are correct EXCEPT:

Explanation

## Inflammatory Phase of Wound Healing **Key Point:** The inflammatory phase (0–5 days) is dominated by hemostasis, removal of debris, and recruitment of immune cells — NOT collagen synthesis. Collagen deposition is the hallmark of the proliferative phase, which begins around day 3–5 and peaks at 5–21 days. ### Timeline and Cell Recruitment | Phase | Duration | Primary Cell | Key Function | |-------|----------|--------------|---------------| | Hemostasis | 0–15 min | Platelets | Clot formation | | Inflammatory | 0–5 days | Neutrophils (24–48 h), Macrophages (48–72 h) | Debris removal, cytokine release | | Proliferative | 3–21 days | Fibroblasts | Collagen synthesis, angiogenesis | | Remodeling | 21 days–2 years | Fibroblasts | Cross-linking, scar maturation | ### Why Option 3 Is Incorrect **High-Yield:** Collagen deposition does NOT begin in the inflammatory phase. The first collagen fibers appear around day 3–5 (at the transition to proliferative phase), but the bulk of collagen synthesis occurs during the proliferative phase (days 5–21). During the inflammatory phase, the focus is on: - Hemostasis and fibrin clot stabilization - Neutrophil infiltration and bacterial killing - Macrophage recruitment and wound debridement - Release of growth factors (PDGF, TGF-β, FGF) that will later drive fibroblast recruitment ### Why the Other Options Are Correct - **Option 1 (Neutrophils):** Neutrophils arrive within 24–48 hours, peak at 3–5 days, and are then replaced by macrophages. This is textbook inflammatory kinetics. - **Option 2 (Macrophage recruitment):** Macrophages are recruited by fibrin degradation products, complement fragments (C5a), and bacterial lipopolysaccharides. This is a well-established chemotactic mechanism. - **Option 4 (Duration):** The inflammatory phase typically resolves by day 5 in uncomplicated wounds, after which the proliferative phase dominates. **Clinical Pearl:** Prolonged inflammation (>5 days) suggests infection, foreign body, or chronic wound disease and warrants investigation.