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Class Progress
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Chapter Listing

Wound Care - DEMO

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Remodeling Phase

The final phase of wound healing, called the remodeling phase, is characterized by continued synthesis and degradation of the extracellular matrix components trying to establish a new equilibrium. It involves a reorganization of the new collagen fibers forming a more organized lattice structure that progressively continues to increase the wound tensile strength. This phase begins when the level of collagen production equals the level of degradation. At the end of the proliferative phase, type III collagen, which is the prevalent type deposited during that phase, is gradually degraded and replaced by the stronger type 1 collagen. The disorganized collagen fibers present at the end of proliferation are rearranged, cross-linked, and aligned along tension lines. The onset of the remodeling phase may vary extensively, depending on the size of the wound and whether it was initially closed or left open, ranging from approximately 3 days to 3 weeks. This phase can then last up to two years, depending on wound type. As time goes by, the tensile strength of the wound increases, with the strength approaching 50% that of normal tissue by three months after the injury. The regained tensile strength in a wound will never approach normal. In fact the maximum tensile strength that a wound can ever achieve is approximately 80% that of normal skin. Normal dermal collagen, on a per weight basis, approaches the tensile strength of steel. In contrast, collagen fibers formed in scar tissue are much smaller and have a random appearance. This scar tissue is always weaker and will break apart before the surrounding normal tissue, but generally achieves all of the functions of normal skin. As the physiologic activity and excess blood supply at the wound site decrease, the new scar loses its red appearance and a mature scar emerges.
 

Q: [Extracellular matrix] - The extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions.
Q: [Proliferation] - Growth of cell populations, where one cell (the "mother cell") grows and divides to produce two "daughter cells"
Q: [Lattice] - A structural criss-crossed framework
Q: [Equilibrium] - The condition of a system in which competing influences are balanced
Q: [Collagen] - A group of naturally occurring proteins. It is the main protein of connective tissue.The main component of connective tissue, and the most abundant protein in mammals
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