Tissue injury & repair Flashcards
What are the 2 processes of healing?
Regeneration and repair
Define regeneration
Growth of cells and tissues to replace lost structures e.g. liver regeneration
Define repair
A combination of regeneration and scar formation, the relative contribution is dependent on the capacity to regenerate, the extent of the injury and the extent of scarring/fibrosis
In mammals what are the 2 examples of true regeneration?
Epithelium following a superficial skin injury
Bone following a fracture
Which 2 mechanisms of regeneration are considered “mostly compensatory”?
Hypertrophy & hyperplasia
What is healing by the first intention?
where the edges of the wound are near to each other. e.g. surgical wounds sutured together
what is healing by the second intention?
Where the edges of the wound are not close to each other and there is more granulation tissue
In healing by the second intention the inflammation is more intense, why?
Because there is more necrotic debris, exudate and fibrin to remove.
What are the local factors affecting wound healing?
Size Location Type Infections Mechanical forces Foreign bodies
What are the systemic factors affecting wound healing?
Nutritional status
Metabolic status e.g. diabetes mellitus
Circulatory/vascular status
Hormones
Deficient scar formation and formation of contractions are examples of…
Complication of repair
Name some examples of complications of excessive repair of tissues
Excessive granulation tissue
Excessive collagen accumulation leading to a hypertrophic scar
Keloid scarring
What percentage of cases have post operative wound infections?
3%
What measures are taken to prevent surgical wound infections?
Regular dressing changes
Keeping the area clean
Post op what can indicate an internal bleed?
Excessive haemorrhage
