There is granulation tissue after the wound scabs, which is a normal skin healing process. Granular tissue hyperplasia and scar formation began on the third day, and granulation tissue grew from the bottom and edge of the wound to fill the wound. The capillary growth is about 0. 1-0.6 mm per day. Its direction is mostly perpendicular to the wound surface and curved in a ring shape. Granulation tissue has no nerve, so it has no feeling. On the 5th to 6th day, fibroblasts produced collagen fibers, and the formation of collagen fibers was very active in the following week, and then gradually slowed down. With more and more collagen fibers, the scar formation process appears, and the scar is completely formed about one month after injury. The collagen fibers in scars are finally parallel to the skin surface, which may be due to local tension.
Suggestion: Healthy granulation tissue is very important for epidermal regeneration, because it can provide nutrients and growth factors needed for epithelial regeneration. If granulation tissue can not fill the wound for a long time to form a scar, epithelial regeneration will be delayed; In another case, granulation tissue is overgrown due to foreign bodies and infection, which is higher than the skin surface and will also prevent epidermis from regenerating, so it is often necessary to remove it in clinic. If the wound is too large (generally considered to be larger than 20cm in diameter), it is difficult for the regenerated epidermis to completely cover the wound, and skin grafting is often needed.