OSM Wound Healing Flashcards
What are 2 causes of tissue damage?
- Physical
2. Chemical
What are the 3 stages of wound healing?
- Inflammatory
- Fibroplastic
- Remodeling
When does the inflammatory stage of wound healing begin?
At the time of injury
How long does the inflammatory stage of wound healing last?
3-5 days
What are the 2 phases of the Inflammatory stage of wound healing?
- Vascular
2. Cellular
What is the first phase of inflammatory stage of wound healing involving vasoconstriction and coagulation, then WBC release Histamines and Prostaglandins E1 and E2 which cause vasodilation allowing leukocytes to migrate into the interstitial tissues?
Vascular
What causes edema and how?
Fibrin causes lymphatic obstruction causing Edema
The 2nd phase of the inflammatory stage of wound healing, the Cellular phase, is triggered by what?
Activation of serum compliment (C3a & C-5a) caused by tissue trauma
What 2 complement factors are chemotactic for neutrophils to Marginate and Diapedese?
C3a and C5a
What is the term for the process by which a neutrophil sticks to the vessel wall?
Margination
What is the term for a Neutrophil migrating through vessel wall?
Diapedesis
What is the term for neutrophils releasing their lysosomal enzymes, the proteases that destroy bacteria, foreign material and digest necrotic tissue?
Degranulation
What does a Macrophage do to foreign and necrotic material?
Phagocytize
Which lymphocytes produce antibodies?
B lymphocytes
Which lymphocytes are the helper, suppressor, and killer cells?
T lymphocytes
What is the flow of the cellular phase of the Inflammatory stage of wound repair?
tissue injurystimulates split complement factors C3a & C5acause chemotaxis, margination, diapedesis of NeutrophilsNeutrophils degranulate to destroy bacteria, foreing material, and digest necrotic tissue, aided by macrophages to clear the debrisB & T lymphocytes accumulateB lymphocytes form antibodies and further aides immune system in fighting infection
What are 5 signs of inflammation?
Erythema –redness Edema –swelling
Warmth – vasodilation Pain Loss of function
What are 3 things that cause pain in wound healing?
- Histamines
- Prostaglandins
- Pressure from edema
What 2 things lead to loss of function in wound healing?
- Edema
2. Pain
In epithelialization, how does the epithelium proliferate/migrate?
The free edge of the epithelium advances over wound until it contacts other epithelial cells
What do cells without cell to cell contact do in wound healing?
Release chemical mediators that regulate cell growth.
When cells contact each other they stop releasing chemical mediators and cell proliferation stops. This is called what?
Contact inhibition
In the 2nd phase of wound healing, the Fibroplastic stage, what crisscrosses the wound as a result of coagulation forming a latticework on which fibroblasts can begin laying down ground substance and tropocollagen?
Fibrin strands
When does the fibroplastic stage of wound healing take place?
3-4 days after injury
What are the 2 phases of the Fibroblastic stage of wound healing?
- Migratory Phase
2. Proliferative Phase
During which phase of the Fibroblastic stage of wound healing does Epithelial migration continue?
Migratory Phase
What removes necrotic materials during the Migratory phase of Fibroplastic Stage of wound healing?
Leukocytes
How do capillaries in-grow to the wound area during the Migratory phase of the Fibroplastic stage of wound healing?
Bud from existing blood vessels at margin of wound and run along fibrin strands to cross wound
Fibroblasts migrate into the wound during the Migratory phase of the Fibroplastic stage of wound healing and do what?
Stimulate pluripotential mesenchymal cells to begin tropocollage production
What occurs if wound placed under early tention (no sutures) during wound healing?
Wound pulls apart, increasing the scar
What 3 things occur during the Proliferative Phase of the Fibroplastic Stage of wound healing?
- epithelial thickness increases
- Collagen fibers laid down by fibroblasts
haphazardly - Capillaries interconnect to increase vascularity
How long does the Proliferative phase of the Fibroplastic Stage of wound healing last?
2-3 weeks
What is the resulting strength of the repaired wound at the end of the Fibroplastic Stage?
75%
What do fibroblasts lay down haphazardly that ?undergoes crosslinking to become collagen
Tropocollagen
What are 2 things laid down by fibroblasts to produce collagen?
- Ground substance (mucopolysaccharides)
2. Tropocollagen
What is the 3rd stage of wound healing that results in wound maturation
Remodeling stage
What is the length of the Remodeling stage of Wound Healing?
It continues indefinitely
What happens to the epithelium during the Remodeling Stage of Wound Healing?
Epithelial stratification
What is the resulting strength of the wound after the collagen has remodeled in the Remodeling stage of of Wound Healing?
85% of original strength
When the fibroblasts disappear in the Remodeling Stage of Wound Healing, what will be the character of the scar?
The scar will be softer
When the Vascular integrity is reestablished in the Remodeling Stage of wound healing, will the volume of vessels in the wound increase or decrease, and what will be the resulting erythema?
The volume of vessels will decrease and there will be LESS erythema
Why is there a loss of flexibility in the healed tissue of a wound?
There is no new elastin.
What occurs during wound contraction?
The wound edges migrate together, wound contracture
In wounds where the edges are not or will not be placed in apposition, what decreases the size of the wound?
Wound contraction
What can occur if a wound, such as a full thickness (3rd degree) burn, is not covered by a skin graft?
wound contraction that is deforming and debilitating
What can limit debilitating wound contracture?
Skin graft placed early, e.g. vestibuloplasty skin graft
What are 4 factors impairing wound healing?
- Foreign material
- Necrotic tissue
- Ischemia
- Tension
What is Anything non self, such as bacterial infection, or the foreign debris that shelters bacteria from host defenses?
Foreign material
What is a barrier to in-growth of reparative cells, also shelters bacteria from host defenses?
Necrotic tissue
What can act as a nutrient source for bacteria?
Hematoma
True or false: Ischemia can lead to further tissue necrosis
True
What is decreased and increased in Ischemia?
Decreased delivery of antibodies, WBC, antibiotics, oxygen, nutrients.
Increased risk of infection and delayed wound healing
What are 7 causes of Ischemia?
- Tight/incorrect sutures
- Improperly designed flaps(small base to height flap)
- Excessive external pressure to the wound
- Excessive internal pressure to the wound – hematoma
- Systemic hypotension
- Peripheral Vascular Disease
- Anemia