Term
| most favourable outcome of wound healing and describe how occur |
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Definition
most favourable: return to normal function and structure
how: minor damage, no complications and cells able to regenerate |
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Term
| what may cause unfavourable wound healing (5) |
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Definition
- extensive damage
- tissue not able to regenerate
- infection -> abscess or granuloma formation
- persistance of fibrin in lesion |
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Term
| why unfavourable wound healing may occur |
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Definition
| destroyed tissue is replaced by scar tissue |
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Term
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Definition
primarily consist of collagen that fills lesions
not as strong as initial tissue, nor carries same physiological functions |
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Term
| wound stages and when begin and duration of each |
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Definition
1) reconstructive phase: begins 3-4 days after injury. Lasts for as long as 2 weeks
2) maturation phase: begins 'several' weeks after injury. Complete within a few years (usually) |
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Term
| components that initially seal wound and purpose |
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Definition
| cross mesh fibres containing fibrin and trapped platelets: unite wound edges and serves as a physical barrier to prevent entry of pathogens |
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Term
| what happens after clot for healing to proceed |
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Definition
| fibrin clot must be replaced by normal or scar tissue |
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Term
| roles of macrophage in reconstructive phase (2) |
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Definition
1) invade dissolving clot and clear debris and dead cells
2) secrete biochemical mediators- promotes healing |
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Term
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Definition
| process in which tissue grows into wound from healthy connective tissue surrounding the wound. This granulation tissue is full of new capillaries and give the healing wound a red colour |
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Term
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Definition
| epithelial cells grow into the wound from surrounding tissue |
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Term
| describe process of epithelialisation |
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Definition
| epithelial cells migrate under clot/scab -> to unravel collagen -> migrating epithelial cells contact similar surrounding cells from wound edges -> to halt migration and proliferation -> epithelial cells active, differentiation -> toto various epidermal layers |
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Term
| environment condition to hasten wound healing and why |
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Definition
| moist: prevent fibrin clot to become a scab |
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Term
| fibroblast and period of action |
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Definition
| are cells that secrete collagen and other connective tissue proteins to be deposited in debrided (areas with removed nonliving cells) areas 6 days after fibroblast entry into lesion |
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Term
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Definition
contains high concentrations of amino acids.
chemically reacts to form collagen fibres during the healing process |
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Term
| duration of collagen reactions |
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Definition
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Term
| when is contraction noticeable in reconstructive phase |
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Definition
| usually 6-12 days after injury |
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Term
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Definition
| specialised cells responsible for wound contraction |
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Term
| how does wound contraction occur |
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Definition
| plasma membranes and myofibroblasts make connections between neighbouring cells by creating tension between neighbouring cells when they contract their fibres and anchoring to the wound bed |
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Term
| 3 aspects from reconstructive phase that continue in maturation phase |
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Definition
- assembly of collagen matrix
- tissue regeneration
- wound contraction |
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Term
| summarise processes that take place in reconstructive phase |
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Definition
1) blood clotting
2) replacing of fibrin clot
3) macrophage clearing and secreting
4) granulation tissue growth
5) epithelialisation
6) fibroblast secretion: collagen and and connective tissue proteins
7) reaction: collagen fibres
8) wound contraction: myofibroblasts |
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Term
| what happens in maturation stage |
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Definition
| scar tissue remodelled and scar becomes avascular (capillaries disappear and area is without blood supply) |
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Term
| when scar tissue has gained 2/3rds of eventual maximum strength |
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Definition
| 2-3 weeks after maturation has begun |
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