Cell injury can lead to inflammation, cell death, and healing responses that aim to restore normal structure and function. There are two main types of wound healing - primary union which involves clean surgically incised wounds healing within 5 days through hemorrhaging, acute inflammation, epithelial changes, and collagen formation. Secondary union occurs with open wounds and large tissue deficits, involving longer inflammatory and granulation tissue formation phases before wound contraction over 14 days leads to scar tissue formation and healing. Factors like infection, blood supply, foreign bodies, movement, age, nutrition, and diseases can influence the wound healing process and potentially lead to complications.

1. Cell Injury  Inflammation
Cell Death
Healing

2. Healing

3. Healing
Response to injury in an attempt to
restore normal structure & function.

4. Regeneration
and
Repair

5. Wound Healing
•Primary Union
•Secondary Union

6. Primary Union
• (Healing by first intention)

7. • Clean, surgically incised wound.
• Minimal loss of cells n tissue.

8. Steps in Primary wound
healing
• Initial hemorrhage
• Acute inflammatory response:
Neutrophils - macrophages
• Epithelial changes: new
multilayered epithelium in 5
days.
• Organization: Fibroblasts and
collagen fibres.

9. Injury
0 3 5 7
Acute Inflammation
Initial hemorrhage
Neutrophils
replaced by
macrophages
Fibroblast
invasion
Multilayered new
epidermis formation
Collagen fiber
formation
Scar tissue
formation

10. Secondary union

11. • Open wound, large tissue deficit.
• Extensive loss of cells n tissue
Steps:
• Initial hemorrhage
• Inflammatory phase
• Epithelial changes
• Granulation tissue
• Wound contraction

12. Granulation tissue formation
Granular Red appearance is due
to newly formed blood capillaries.

14. Contraction of wound
• Contraction Due to –
Dehydration, Collagen
contraction, Myofibroblasts.
• Starts after 2,3 days.
• Complete by 14th day.
• ~ Rapid healing

16. Factors influencing Healing
Local factors:
• Infection
• Blood supply
• Foreign body
• Movement

17. Factors influencing Healing
Systemic factors
• Age
• Nutrition
• Systemic infection
• Diabetes

18. Complications of wound
healing
• Infection
• Pigmentation
• Hypertrophied scar (Keloid)
• Neoplasia
• Excessive contraction

19. Keloid
Keloid Sole foot