Squamous epithelium: proliferation of cells from the basal layer at the edge or bottom of the wound

Mucosal epithelium: repaired by division and proliferation of adjacent basal cells

The basement membrane is not damaged and can be fully restored

If the basement membrane is destroyed, it is difficult to regenerate

Liver: As long as the mesh scaffold of the liver lobules is intact, even if the necrotic area is large, the regenerated liver cells in the peripheral areas of the liver lobules can extend along the scaffold and restore the normal structure.

Immature cells-chondroblasts-chondrocytes

It is completed by budding. The adventitial cells are derived from fibroblasts. If they form arterioles, venules, and smooth muscles, they are differentiated from extravascular undifferentiated mesenchymal cells.

After the major blood vessels are severed, surgical suturing and connective tissue connection are required to form scar repair.

It can be restored if the damage is not serious. Scar repair after complete disconnection

Regenerable, fibrous scar repair for larger injuries

scar repair

Repaired by glial cells and their fibers to form glial scars

When damaged, if the nerve cells connected to it are still alive, they can be completely regenerated. If the two severed ends are too far apart, or the distal end is lost due to amputation, the regenerated axons are mixed with the proliferated connective tissue and curled into a ball, which is called a traumatic neuroma, and intractable pain may occur.

New thin-walled capillaries (growing perpendicular to the surface)

Immature connective tissue composed of proliferating fibroblasts

Infiltration of inflammatory cells (white blood cells)

Bright red, granular, soft and moist, like fresh granulation, hence the name granulation tissue.

Anti-infection and wound protection

Fill wounds and other tissue defects

Organize or encapsulate necrosis, thrombus, inflammatory exudate and other foreign bodies

Granulation tissue matures into fibrous connective tissue and becomes scar tissue after aging

Connect damaged wounds, fill defective tissues, and maintain the structural integrity of tissues and organs

Maintain the robustness of tissues and organs

Scar shrinkage limits joint movement or narrows the lumen

scarring adhesions

Extensive fibrosis and hyaline degeneration, which can harden organs

hypertrophic scar

Seen in wounds with few tissue defects, neat wound edges and no infection, and tight wound joints

Seen in wounds with large tissue defects, uneven wound edges, failure to heal neatly, or wounds with infection

Compared with primary healing: