As the pink granulation tissue forms from the periphery of the wound, epithelial cells begin to form a new top layer over the granulation tissue, this is called . , has the ability to contract, pulling on collagen fibres. This in turn pulls to edges of the defect closer together, speeding up the healing process. A specialized type of fibroblast, the 3. Maturation Phase The maturation phase of healing begins at seven to twenty-one days after injury and persists for up to six months to a year, depending on the severity of injury. There is some overlap with the granulation phase of healing. During this phase fibroblast activity decreases notably though contraction of the scar continues. Collagen fibres are rearranged in response to mechanical stress. The fibres are aligned longitudinally along the lines of stress to increase the of the scar. By three months after injury a scar has eighty percent of the strength of the original tissue and may continue to strengthen as the scar fully matures. Mature scars are grey or pale pink in colour, depending on the colour of the surrounding skin. They are avascular, sensitive to pain and relatively strong. Eventually some scars are covered by hair while others never regain hair. Some scars become raised as they mature while others form a depression. This occurs due to the contraction of the scar tissue and is affected by mechanical stress on the scar during the proliferation and maturation phase of healing.
Healing Intention
With human attention wound healing can be improved. Basic sanitization and minor first aid may be all that is required to prevent infection and promote rapid healing with little scarring and loss of function. Occasionally more drastic measures are required to achieve the best outcome for a wound. Categories have been defined for wound healing depending on the approach and timing of human intervention in the healing process.
Primary Intention Healing
Primary intention healing is said to be the most desirable outcome for a wound. In primary intention healing a wound is approximated and closed by stitches or other wound closing devices. For this to occur, the wound must be , have neat edges and be sterile. A veterinarian should attend to determine if stitches are the most appropriate treatment, and to perform the stitching. Examples of wounds that would be benefitted by primary intention healing include surgical incisions, long moderately shallow wounds and tears of the eyelid, nostril or lip.
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