Wound Healing Flashcards
What are the four phases off wound healing?
Haemostasis
Inflammatory
Proliferative
Maturation & remodelling
how long does it take for haemostasis and moon healing to occur?
This happens 5 to 10 minutes post injury.
Essentially this begins with endothelial injury and subsequent vasoconstriction. Platelet activation results of the side of kinds of growth factors been released. And then fibrin clot forms.Essentially this begins with endothelial injury and subsequent vasoconstriction. Platelet activation results in the side of kinds of growth factors been released. And then fibrin clot forms.
What point does the does the inflammatory phase of wound healing occur?
Day zero to day 4 post injury
In the inflammatory phase of wound healing, what are the cells that are first to arrive?
Leucocytes
What is the role of monocytes in the inflammatory phase of wound healing?
a. Vital for normal wound healing
b. Signaling normal fibroblast production
c. Predominant cell in wound exudate after the first 48 hours
d. Continue débridement and conclude the inflammatory response.
e. Secrete nitric oxide, which is bactericidal (particularly against Staphylococcus aureus)
At what point does the proliferative phase of healing occur?
Day one to three weeks post injury
At what phase of wound healing do fibroblast migrated to the wound?
Proliferative phase
What are the three events that occurred during the proliferative phase?
Collagen deposition
Epithelialization.
Angiogenesis.
When does maturation and remodelling phase of the healing occur?
Three weeks to one year post injury
Describe the phases of tensile strength and how it increases overtime.
a. At 1 week: 3%
b. At 3 weeks 20%
c. Final tensile strength: 80% of uninjured skin (never reaching the strength of normal skin)
d. Type I collagen: 90%, type III: 10% (similar to uninjured skin)
What are the 12 factors that affect wound healing?
Oxygenation.
Infection.
Nutrition.
Steroids.
Smoking.
Age
Foreign bodies
Edema
Chemotherapy
Radiation
Diabetes.
General health.
Why is oxygenation important in the healing?
- Fibroblasts are O2 sensitive, require partial pressure of oxygen (PaO2) of 30 mm Hg, and can be stimulated to proliferate and synthesize collagen if PaO2 > 40 mm Hg.
- Wound hypoxia is the most common cause of wound infection.
- Acute anemia secondary to hemorrhage is not associated with decreased wound strength.
- Vasoconstriction secondary to pain, temperature, hypovolemia, etc. can cause local tissue hypoxia.
Why does malnutrition affect wound healing?
Serum protein less than 2 g prolongs the inflammatory phase, decreases fibroplasia, and therefore delays tensile strength.
What vitamin is essential in wound healing?
Vitamin C is an essential cofactor in collagen synthesis (no benefit to supranormal levels of vitamin C).
Why do steroids affect wound healing?
- Steroids inhibit wound macrophages, fibroplasia, angiogenesis, and wound contraction.
- They increase the risk for infection.