Answer:
The macrophage is the most important cell present in the healing wound and appears to act as the key regulatory cell for repair. It is the predominant cell type within the wound between 48 and 72 hours after wounding. It functions as a phagocytic cell as well as being the primary producer of growth factors responsible for: both the production and proliferation of the extracellular matrix by fibroblasts, the proliferation of smooth muscle cells, and the proliferation of endothelial cells. Without the macrophage, there are severe alterations in wound healing with poor debridement, delayed fibroblast proliferation, inadequate angiogenesis, and poor fibrosis.
The lymphocyte is the last cell to enter the wound during the inflammatory phase (up to 72 hrs after wounding). Its role in wound healing has not been clearly defined, though it is attracted to the wound by interleukin-1, which is believed to have a key role in the regulation of collagenase.