Pathoma - Wound healing Flashcards
Examples of labile tissues
Stem cells that continuously recycle
e.g. small and large bowel, skin, bone marrow
Examples of stable tissues
Cells that are quiescent but can regenerate when necessary
e.g. hepatocytes
Examples of permanent tissues
Lack regeneration potential:
(1) Myocardium
(2) Skeletal musle
(3) Neurons
These cells must heal via repair (cannot heal via regeneration)
What are the 3 components of granulation tissue?
(1) Fibroblasts
(2) Capillaries
(3) Myofibroblasts
What is the function of fibroblasts
Deposition of Type III collagen
What is the collagen transition involved in scar formation
Type III collagen replaced with Type I collagen
What enzyme is required to remove type III collagen
Collagenase
What is the cofactor for Collagenase
zinc
What role does TGF-a play in tissue repair
TGF-a is an epithelial and fibroblast growth factor
What role does TGF-B play in tissue repair
TGF-b is an important fibroblast growth factor + anti-inflammation
What role does Platelet-derived growth factor (PDGF) play in tissue repair
growth factor for endothelium, smooth muscle, and fibroblasts
What role does fibroblast growth factor (FGF) play in tissue repair
important for angiogenesis, also mediates skeletal development
What role does vascular endothelial growth factor (VEGF) play in tissue repair
important for angiogenesis
What is the function of myofibroblasts
Contraction of the wound after it has been filled with granulation tissue
What contains Type I collagen
Bone, skin, tendon, fascia, cornea, late wound repair
What disease has decreased collagen type I production
Osteogenesis imperfecta
What contains Type II collagen
Cartilage, vitreous body
Remember: 1 - strong 2 - slippery 3 - bloody 4 - BMs
What contains Type III collagen
skin, blood vessels, uterus, granulation tissue
What disease has deficient type III collagen
Vascular Ehlers-Danlos
What contains Type IV collagen
Basement membrane
What disease has deficient type IV collagen
Alport syndrome
What is the collagen deficiency in Ehlers-Danlos
Type V
What is the role of vitamin C in wound repair
hydroxylation of proline and lysine pro-collagen residues
What is the role of copper in wound repair
Copper is a cofactor for lysyl oxidase, which cross-links lysine and hydroxylysine to form stable collagen
