Wound_Healing_Full_Presentation (1).pptx

WOUND HEALING IS A PROCESS BY WHICH SKIN CLOSES AFTER INJURY,IT CAN TAKE FEW DAYS TO SEVERAL WEEKS

1. Wound Healing Phases and Types of Healing Medical Student Notes

2. Haemostasis Phase - Immediate (seconds–minutes) - Vasoconstriction reduces blood loss - Platelet plug formation - Fibrin clot stabilizes - Growth factors released (PDGF, TGF-β, VEGF)

3. Inflammatory Phase (0–3 days) - Goal: Defend and debride wound - Redness, heat, swelling, pain - Neutrophils: phagocytosis, enzymes, ROS - Macrophages: phagocytosis, cytokines, GF secretion - Lymphocytes regulate response

4. Proliferative Phase (3–21 days) - Fibroblasts → collagen (Type III) - Angiogenesis → new vessels - Granulation tissue forms - Epithelialization: keratinocyte migration - Myofibroblasts → wound contraction

5. Remodelling / Maturation (21 days–1 yr+) - Type III → Type I collagen - Collagen cross-linking → ↑ tensile strength - Capillaries regress → scar becomes pale - Scar contracts and matures - Tensile strength reaches 70–80% of normal skin

6. Healing by Primary Intention - Clean wound, edges approximated - Closed by sutures/staples/glue - Minimal granulation tissue - Rapid healing, fine linear scar - Example: surgical incision

7. Healing by Secondary Intention - Wound left open to heal naturally - Large tissue loss, contaminated wounds - Healing by granulation, epithelialization, contraction - Slow healing, large irregular scar - Example: pressure ulcer, burn

8. Healing by Tertiary Intention - Delayed primary closure - Wound initially left open for infection control - Debridement, granulation, then surgical closure - Better result than secondary, slower than primary - Example: contaminated abdominal wound

9. Clinical Relevance - Delayed healing: infection, diabetes, malnutrition, steroids - Hypertrophic scars: raised, confined to wound - Keloids: excessive, extends beyond wound - Chronic non-healing wounds