Cell repair occurs through regeneration using parenchymal or surrounding undamaged cells, or through scar formation using connective tissue to replace damaged cells. Cells are classified as labile, stable, or permanent based on their regenerative capacity. Scar formation results from acute inflammation failure to heal, cell necrosis of permanent cells, or extensive necrosis leaving no cells for regeneration. The steps of scar formation are preparation, granulation tissue ingrowth, fibronectin production, fibrosis, scar maturation, and contraction/strengthening. Fibronectin is a glycoprotein synthesized by fibroblasts, macrophages, and endothelial cells in later wound healing phases. Wound healing stages are primary intention for small, opposed wounds or secondary intention for separated wounds

1. Cell repair
&
wound healing
By
Amira Essam
Medical student
-source-
Short text book of pathology Dr Mohamed danish

2. Cell repair is done by :
Regeneration
• From parenchymal cells of the same cell
type , OR
• Surrounding undamaged cells
proliferation
Scar formation
• Damaged cells are replaced by
connective tissue
OR

3. Regeneration

4. When classify cells according to its
regenerative capacity , we have :
Labile
• Contiously
dividing
Stable
• Have capacity
but not actively
replicate
Permanent
• Incapable of
divide

5. Scar formation

6. When our body forms scars ?
• In acute inflammation when recovery fails to occur
• In cell necrosis :i.e.- necrotic cells are permanent
cells
- Stable cells are destroyed
- Necrosis is so extensive that no cells are available
for regeneration

7. Steps of scar formation
1. Preparation by the lymphatics
2. Ingrowth of granulation tissue
3. Production of fibronectin
4. Fibrosis
5. Maturation of scar
6. Contraction and strengthen

8. fibronectin
Glycoprotein
In early phases of
wound healing its
derived from plasma
In later phases of
wound healing its
synthesized by
fibroblasts,
macrophages and
endothelial cells

9. Wound healing stages:
• Primary intention
- occurs when wound wedges is in good opposition
- small scar formation
- Rapid healing
• Secondary intention
- when wedges are separated
- large scar formation
- slow healing

10. Thanks