During tissue healing, which phase lasts from approximately 4–21 days and is characterized by collagen deposition and tissue formation?

During tissue healing, which phase lasts from approximately 4–21 days and is characterized by collagen deposition and tissue formation?

• A. Hemostasis (immediately after injury)
• B. Proliferation (4–21 days)
• C. Inflammation (0–4 days)
• D. Maturation/Remodeling (weeks to months)

Answer: (B)

The proliferative phase lasts about 4–21 days and is when collagen deposition and tissue formation really take off. After the initial inflammatory response, fibroblasts migrate into the wound and begin laying down collagen and other extracellular matrix, creating granulation tissue that fills defects. New blood vessels form (angiogenesis), epithelial cells proliferate to cover the wound, and the scaffold for new tissue develops, though the tissue isn’t fully strong yet. Later on, the maturation/remodeling phase—weeks to months—reorganizes and cross-links the existing collagen to increase tensile strength, with less new collagen being laid down.

The proliferative phase lasts about 4–21 days and is when collagen deposition and tissue formation really take off. After the initial inflammatory response, fibroblasts migrate into the wound and begin laying down collagen and other extracellular matrix, creating granulation tissue that fills defects. New blood vessels form (angiogenesis), epithelial cells proliferate to cover the wound, and the scaffold for new tissue develops, though the tissue isn’t fully strong yet. Later on, the maturation/remodeling phase—weeks to months—reorganizes and cross-links the existing collagen to increase tensile strength, with less new collagen being laid down.