Wounding and Wound Healing Flashcards
What is the definition of a wound?
Break in the continuity of any body tissue
What are the three stages of wound healing?
- Inflammation and debridement
- Proliferation
- Maturation and remodelling
What does the inflammatory phase begin with?
- starts with haematosis, first few minutes after injury
- damage to vessels
- blood and lymph escapes
- fills the wound
- cleansing/ prevent further contamination
How does haemostasis begin?
- Reflex vasoconstriction (in the first 5-10 mins)
- Reduction in blood loss
- Endothelial damage activates platelets
- Platelet plug then activates vasodilation
- Mast cells release histamine
- Endothelial damage exposes the tissue factor
What is the function of a blood clot?
- Haemostatic plug
- acts as a barrier to infection
- Prevents further fluid loss
- Framework for early wound organisation
- Stabilises the wound edges
What occurs when a blood clot dries?
Dries to form a scab (eschar)
allows healing to occur underneath
eventually sloughs
What occurs in the inflammation and debridement phase?
Migration of leukocytes into the wound
Within 6 hours
What is the function of the neutrophils within the wound?
- In 0-48 hours they destroy bacteria
- Vasodilation
- Pro-Inflammatory mediators
- act as a component of pus
What is the function of monocytes in the wound?
Essential for wound healing
* transform into activated macrophages
* phagocytose/ destroy bacteria
* remove the clot
* debride necrotic tissue
What are the gross signs of inflammation?
- Heat, Redness, Swelling, Pain, Loss of Function
What is the ‘big inflammatory focus’?
- Not enough proteins/ Leukocytes to have an inflammatory response in the entire area
- Prolonged pro-inflammatory response
What is persistent inflammatory focus?
Prolonged pro-inflammatory phase
What are systemic Inflammatory Effects?
Continued vasodilation -> Hypotension
Barrier of the GIT is reduced
Hepatic Inflammation
What is the function of the proliferative phase?
Restores skin integrity by filling the wound with new tissue
What occurs during fibroplasia?
- Fibroblasts proliferate and migrate into the wound
- differentiation into myofibroblasts
- Migrate along the ECM
- Synthesis of collagen type I
- Requires Oxygen and Nutrition
What is angiogenesis?
New capillaries form
* endothelial cells migrate into the ECM
* Capillaries are fragile and highly permeable
What is epithelialisation?
- migration of epidermal cells at the margin of the wound
- Proliferation of epidermal cells behind the leading edges
- epidermis comes from wound margins after granulation tissue
When is the new epidermis visible?
- large wounds may not be complete
- can be thin and easily traumatised
- adnexal structures do not regenerate
- pigmentation is variable
What is the granulation tissue?
Combination of new capillaries, fibroblasts and connective tissue
When does wound contraction occur?
days 5-9 post injury
* reduction in wound size
* surrounding skin then stretches
* may be a problem over joints/ body openings
* continues until wound edges meet
What is the function of maturation/ remodelling?
- Increases mechanical strength of the wound
- reorganisation of connective tissue
- rearrangement of collagen bundles
- reduction in collagen content
How would you manage inflammation?
- Cleaning
- debridement
- protection from further contaminants
- antibiotics if infected
What is a seroma?
lump or mass that forms when clear fluid builds up in the tissue
