Week 1: Inflammation Response/ Wound Repair Flashcards
What is the goal of wound healing?
To restore the structural and functional integrity of the injured tissue
What are the outcomes of wound healing?
Regeneration and resolution
Repair
What is regeneration and resolution?
Returns tissue back to original structure and function
What is repair?
Returns tissue structure but not function
What are some tissues that undergo regeneration and resolution when damaged?
Corneal epithelium
Bone
Superficial skin
What are some tissues that repair when wounded?
Heart, brain, retina
What does wound healing begin with?
Acute inflammation
What are the phases of wound healing?
Inflammation phase
Proliferative Phase
Maturation Phase
When does the inflammatory phase occur?
Day 2-5
When does the proliferative phase occur?
Day 5 to week 3
When does the maturation phase occur?
Week 3 to year 2
What happens in the inflammatory phase?
- Acute inflammatories send phagocytic cells and clotting factors to the damaged site:
- blood clots, bleeding stops
- destroys foreign agents
- Constriction of blood supply
- formation of scab
- Debridement: removing clots, microorganisms, red blood cells, and dead tissue cells. Prepares for tissue growth. Phagocytosis by macrophages.
- Edema dissipates after debridement.
What happens in the proliferation phase?
- Granulation tissue develops (vascularized connective tissue full of macrophages)
- Angioblast proliferation (blood vessel growth)
- Fibroblast proliferation (collagen and extracellular matrix synthesis, also precursor for scar)
- Contraction ( Myofibroblasts gradually close wound)
- Epithelialization (Matrix Metalloproteinases remodel new collagen in wound. Cell differentiation occur when edges of wound meet.)
What happens during the maturation phase?
Continued cellular differentiation (epithelium)
Scar remodeling, trying to make the scar smaller
Collagen becomes more organized
Granulation tissue becomes connective tissue
Can last up to 2 years.
Local factors that affect wound healing
Size Infection Location Mechanical factors Foreign bodies