Principles of Wound Healing Flashcards
Name the four phases of wound healing
Injury
Inflammatory phase
Proliferation phase
Maturation phase
What is primary intention vs secondary?
Primary is post surgical closure.
Secondary is when the wound is left open for healing such as an ulcer.
This phase of wound healing is characterized by hemostasis and inflammation.
The inflammatory phase lasting 1-2 days.
Collagen is exposed activatin the clotting cascade.
Platelets arrive first followed by neutrophils.
This phase of wound healin is characterized by epitheliazation and collagen deposition.
Proliferative phase.
2/3 days - 7/10 days.
Collagen is layed down randomly, tensile strength is not added yet!!!!
During which phase of wound healing does the organization of collagen for tensile strength occur?
During the maturation phase!
Note that collagen is layed down during the proliferative phase however this cartilage is layed out randomly without tensile strength yet being formed.
Describe the difference in epithelialization if the basement membrane is intact vs not inact.
When the basement membrane is intact, the cells will migrate as normal AKA like a first degree burn showing restoration in 2-3 days.
If the basement membrane is destroyed the wound is epithelized from the periphary like 2nd or 3rd degree burns.
What molecule specifically stimulates aniogenesis during the proliferative stage?
Angiogenesis is stimulated by TNF-alpha!
During which time frame does the maturation phase occur?
10 days - 1 year.
Wound contraction occurs during this phase.
How long does it take until a wound reaches its maximum tensile strength?
One year.
The tensile strength is 30% of normal skin.
Why are sutures typically taken out around days 10-14?
Because the tensile strength developed from fibroblasts is strong enough at this point to hold the wound closed.
RMEMBER maturation occurs first at 10th day, this is when contraction occurs.
What serves as an accetable treatment option for keloid?
Intralesional corticosteroid injections.
What is a hypertrophied scar?
Widened or unsightly scar that does not extend beyond the original boundaries of the wound.
