Fibroblastic and Remodeling Phase - Class 1 Flashcards
fibroblastic stage
formation of collagen and repair of CT
fibroblastic stage overlaps w/
inflammatory phase and epithelization
how long does the fibroblastic stage last
2-3 days to 2-4 weeks
what is the quality of the scar determined by
fibroblastic phase
what is the fibroblastic stage composed of
4 stages
4 stages of fibroblastic stages
angiogenesis
collagen production
wound contraction
re-epithelialization
angiogenesis (stages)
completion of this process
collagen production
granulation tissue formation
what does the fibroblastic stage consist of
rapid cell growth and replication
production of extracellular matrix (to fill the wound deficit)
wound resurfacing
angiogenesis
creation of new blood supply by forming new blood vessels
increase circulation/remove waste and edema
angioblasts
endothelial cells that make up blood vessel walls adjacent to the zone of injury
connect with other vessels to form new capillary loops
fibroblasts
aid in formation of granulation tissue
granulation tissue
temporary lattice of vascularized CT that fills the defect of the wound
as it matures it is replaced by scar tissue
the hallmark of tissue repair
formation of granulation tissue
what does granulation tissue consist of
proliferating fibroblasts and vascular endothelial cells
occurs int he first 24-72 hours of the repair process
wound contraction
draws margins together
myofibroblasts are the driving force
begins on day 4 and ends in 2-3 weeks
what type of wounds contract faster
linear wounds
which wounds contract slower
circular wounds
re-epithelialization/scar formation
keratinocytes migrate across the wound surface
epithelial cells cannot migrate over nonviable tissues –> they must reach O2 rich scaffolding of the granulation tissue
re-establish surface cover
when is the fibroblastic phase complete
when wound is resurfaced
fxn of the remodeling phase
maturation of scar tissue
granulation tissue matrix is strengthened and reorganized
when is there successful completion of the remodeling phase
wound is closed
sufficient tensile strength
mimic normal
sufficient tensile strength
early on only 15%
forces applied in graded fashion
mimic normal
alignment
orientation
tensile strength
mobility
scar looks like the rest of the skin
successful remodeling phase requires
good synthesis/lysis balance
production of new collagen
removing of old collagen
2 theories of new collagen
induction theory
tension theory
induction theory
less common
scar tissue mimics tissue surrounding it
tension theory
new collagen is
-laid down according to stress/tension on tissue
-w/o stress
-laid down in haphazard direction with less fiber distance
-results in cross-linking
adhesions
with loss of H2O –> critical fiber distance is decreased
with immobilization –> movement and stress decreased
