Granulation tissue appears within 2-3 days after tissue injury and consists of new capillaries and proliferating fibroblasts that promote wound repair.
Tissue repair begins with the proliferation of granulation tissue, which dissolves and absorbs necrotic tissue and other foreign bodies in the injured area, and fills in the tissue defect. Afterwards, the granulation tissue gradually transforms into collagen fiber-based scar tissue, and the repair is complete.
The granulation tissue is bright red granular and soft and moist to the naked eye, and is named after its resemblance to a tender bud of flesh. Granulation tissue plays an important role in the wound repair process, including anti-infection, filling the defective tissue, mechanizing or wrapping necrotic tissue and inflammatory exudates or other foreign bodies.
Over time, fibroblasts proliferate and migrate, extracellular matrix components accumulate and fibrous tissue rebuilds, and a fibrous scar gradually forms on the wound.