Wound Healing Flashcards
What is regeneration?
Replacement of damaged tissue from similar cells proliferated by surrounding cells
What is repair?
Replacement of damaged tissue by granulation tissue which turns into fibrous scar tissue
What is the difference between primary and secondary intention?
Primary: wound edges are close together
Re-epitheliasation
Secondary: wound edges are further apart
Granulation tissue forms
Contract then re-epitheliasation
How do small skin wounds repair themselves?
1 hour: haemostasis, platelet plug, fibrin clot
2 days: inflammation and debridement
1-3 days: re-epithelialisation
5 days: granulation tissue
>5 days: maturation, remodelling, contraction
What inhibits blood clot formation?
Aspirin
Warfarin
Factor VII deficiency
What is granulation tissue made up of?
Loose cellular connective tissue
Plump fibroblasts
Irregular blood vessels
Inflammatory cells
How is wound healing controlled?
Cell-cell interactions
Cell-matrix interactions
Autocrine/paracrine signalling
Depletion of what cells impair wound healing?
Monocytes and so macrophages
What do macrophages produce in wound healing?
Growth factors: fibroblast and endothelial cell
What factors limit wound healing?
Age
Nutrition
Glucocorticoids
Diabetes
What local factors are important in wound healing?
Blood supply
Infection
Irritation
Wound edges
Ionising radiation
What are complications of wound healing?
Weak scars
Keloids
Hypertrophic scars
Pigmentation
Hernia
What is a keloid?
Sharp elevated scar progressively enlarging
Excess amounts of collagen
What is a hypertrophic scar?
Similar to keloid - elevated sharp
Does not spread beyond margins of original wound
