9.21 Injury, Inflammation, Healing 9 Flashcards
Proliferation and migration phase occurs when?
between 2-20 days
What occurs during proliferation and migration?
- neovascularization/angiogenesis
- tissue gaps filled
- fibroblasts synthesize collagen, elastin, and proteoglycan cross-links
angiogenesis process
- endothelial cells at edge proliferate and establish network
- grounded in connective tissue matrix
What causes tissue gaps to be filled in?
- cell migration
- proliferation
- formation of new capillaries
newly healing tissue
granulation tissue
Type III collagen
initially weak and thin
sequence of events with fibroplasia/collagen production
- granulation tissue formed
- Type III collagen
- scar formation
- Type I collagen
scar is formed by these
- glycosaminoglycan (GAG)
- collagen
Type I collagen forms by day
12
Type I collagen
- more mature
- stronger than type III
When does the remodeling and maturation phase occur?
Day 9 - 2 years
During the remodeling phase, what happens to scar tissue?
- reduced
- remodeled
contracture
tissue contracts to pull edges of the wound together
Where can excess scar tissue be problematic?
- skin
- joints
- internal organs
Why is the usefulness of joint manipulation questionable?
because the “break” takes place at the weakest link
How will you know tissue maturation occurs?
- variable
- visible scar will change from vascularized red/pink tissue to less visible skin tone or white
There is always the potential to heal any time
a new scar is pink
Within just a few hours after skin injury, epithelial cells do this
- flatten out to cover a bare area
- divide and migrate across extracellular matrix to begin regeneration
primary intention
- close approximation of tissues
- using sutures
secondary intention
indirect union
tertiary intention
- contaminated wound
- granulation tissue fills large gap
- slower growth
