New Tissue Formation: Epithelialization
Reconstruction takes place in four stages: Detachment, migration, proliferation, and differentiation. Within 24 hours of wounding, the basal cell layer of the epidermis adjacent to the wound thickens and marginal cells elongate and migrate over the wound. The cells at the advancing epithelial edge are followed by a monolayer of new epithelial cells. The new epithelial cells advance across the wound until they eventually meet epithelial cells moving in from the opposite direction. (Think of it as being like the meeting of the transcontinental railroad.)