Briefly describe the repair process of trauma?

① Fibrin filling: local blood vessels dilate and fibrin oozes after trauma, which plays a role in stopping bleeding and sealing the wound.

② Cell proliferation: Shortly after the injury, new cells appeared locally, and fibroblasts and vascular endothelial cells proliferated into capillaries, which together formed granulation tissue and filled the tissue cracks. Fibroblasts synthesize collagen fibers, and the collagen fibers in granulation tissue increase, and the hardness and tensile strength increase accordingly. Epithelial cells proliferate inward from the edge of the wound, covering the wound and the wound tends to heal.

③ Tissue shaping: After cell proliferation and matrix deposition, the damaged tissue was initially repaired. However, fiber tissue and callus can't meet the needs of physiological function in quantity and quality. Part of matrix such as collagen in scar is absorbed, which softens scar and maintains its tensile strength, and part of matrix is absorbed by tissue, while the rigidity of new bone increases instead of decreasing.