2.5 Wound Healing Flashcards
Classification I. Regenerative Capacity: A. labile tissues B.. stable tissues C. permanent tissue II. Processes A. Repair 0. Inflammation 1. granulation tissue (type III collagen) 2. scar formation (type I collagen) B. Collagen Synthesis (Lippincott's Illustrated Review) 1. formation of pro-alpha chains (RER) 2. hydroxylation (RER) 3. Glycosylation 4. pro-alpha chains form pre-collagen 5. extracellular cleavage of pro-collagen molecules produce tropocollagen 6. formation (32 cards)
regeneration
replacement of damaged tissue with native tissue
repair
replacement of damaged tissue with scarring (type I collagen)
- when regenerative stem cells are lost
- in tissues that lack regenerative capacity
classification: labile tissues
highly regenerative due to active stem cells
small and large bowel: stem cells
mucosal crypts
skin: stem cells
basal layer
bone marrow: stem cells
hematopoeic cells
CD34
marker of hematopoeic stem cells
stem cells of lung
type II pneumocytes
classification: stable tissues
quiescent, but can reenter cell cycle
ex.
1. liver
2. proximal tubule of kidney
classification: permanent tissue
responds to injury with repair instead of regeneration
- myocardium
- skeletal muscle
- neuron
Granulation tissue: fibroblasts
deposite type III collagen
Granulation tissue: Capillaries
provide nutrients
Granulation tissue: Myofibroblasts
contract wound
collagenase
a ZINC driven enzyme that removes type III collagen
Type I collagen is found in
bONE
Type II collagen is found in
carTWOlage
Type III collagen is found in
pliability
Type IV collagen is in
basement membrane
TGF-a
epithelial and fibroblasts growht factor
TGF-b
important fibroblast growth factor; inhibit inflammation
PDGF
endothelium, smooth muscle, fibroblast growth factor
FGF hint: name doesn’t give everything away
ANGIOgenesis, skeletal development
VEGF
angiogenesis
wound healing: primary intention
a surgeon brings wound edges brought together
minimal scar formation
