Wound Healing Flashcards
Which 3 phases is cutaneous wound healing divided into?
Inflammation, proliferation and maturation
What does the initial injury (cut on the skin) immediately cause?
Platelet adhesion and aggegation with formation of a clot.
GF release, chemokine and cytokine release, infiltration of neutrophils leading to inflammation
Describe what takes place in the proliferative phase of wound healing?
- formation of granulation tissue
- neutrophils are largely replaced by macrophages
- proliferation and migration of connective tissue cells
- re-epitheliazation of the wound surface
Who are the key cellular figures of tissue repair? What do they do?
Macrophages
They clean the extracellular debris, fibrin and other foreign material at the site of repair; promote angiogenesis and ECM deposition
What is TGF-beta?
The most potent fibrogenic agent - causes fibroblast migration and proliferation
Produced by cells of the granulation tissue
What does TGF-beta increase and decrease the synthesis of?
Increased synthesis of collagen and fibronectin
Decreased degradation of ECM by metalloproteinases
What is the original granulation tissue converted into?
A pale avascular scar, composed of fibroblasts, dense collagen and fragments of elastic tissue and other ECM components
Describe the maturation phase of wound healing
Maturation involves ECM deposition, tissue remodelling and wound contraction with final recovery of tensile strength
Name the factors that influence wound healing?
- Nutrition
- Metabolic status
- Circulatory status
- Hormones such as glcocorticoids (anti-inflammatory)
- Infection
- Size, location and type of wound
Wounds in _______ vascularised areas heal faster than those in _______ vascularised areas?
Highly ; poorly
