In wounds healing by secondary intention, healing occurs from which source?

• A. From the wound edges inward
• B. From the inside out with granulation tissue filling the defect
• C. By immediate epithelial migration across the wound edges
• D. By skin grafting from another site

Answer: (B)

In wounds healing by secondary intention, tissue loss is greater and the edges aren’t brought together, so healing starts from the wound base rather than from the edges. Granulation tissue forms in the wound bed and fills the defect from the inside out, providing a scaffold of new connective tissue and capillaries. As this scaffold develops, epithelial cells migrate over the granulation tissue from the sides toward the center to re-epithelialize the surface. Myofibroblasts also help contract the wound to close it down, though this often results in more scar tissue and longer healing time than primary intention. This is why healing by secondary intention is described as coming from the inside out with granulation tissue filling the defect.