Sequence of general wound healing with an epithelial surface. 1, The wound is created. Blood clots in the vessels; neutrophils migrate to the wound; the wounded edges begin to disintegrate. 2, The wound edges are reapposed with the various tissue planes in good alignment. The epithelium is lost over the wound but starts to migrate. The stromal/ dermal fibroblasts enlarge and become activated. Fibronectin is deposited at the wound edges. The blood vessels begin to produce buds. 3, The epithelium seals the surface. Fibroblasts and blood vessels enter the wound and lay down new collagen. Much of the debris is removed by macrophages. 4, As the scar matures, the fibroblasts subside. Newly formed blood vessels canalize. New collagen strengthens the wound, which contracts. Note that the striated muscle cells in the subcutaneous tissue do not regenerate and are replaced by a scar (arrow).