Wounds

Question 1

Contractures

Answer 1

• occur when unusually pronounced MMP activity results in excessive wound contraction
• Secreted by several different cell types (eg, fibroblasts, macrophages, neutrophils, synovial cells, some epithelial cells), matrix metalloproteinases (MMPs) primarily function in the degradation of collagen and other proteins in the extracellular matrix
• MMP activity is important in wound healing, as it encourages both myofibroblast accumulation at the wound edges and scar tissue remodeling
• amassed myofibroblasts initiate wound contraction during healing by second intention.
• produce deformities of the wound and surrounding tissues, most often on the palms, soles, anterior thorax, or at serious burn sites.

Question 2

Wound dehiscenc

Answer 2

rupturing of a previously closed wound, and can result from insufficient granulation and scar tissue formation, inadequate wound contraction, or excessive mechanical stress

• most commonly occurs in abdominal wounds that are subject to increased intraabdominal pressure,

Question 3

Ulceration of a wound

Answer 3

results from inadequate vascularization during healing and is not associated with excessive matrix metalloproteinase or myofibroblast activity.

• Common sites of ulceration include lower extremity wounds in conjunction with atherosclerotic peripheral vascular disease.

Question 4

Local infection

Answer 4

• most important cause of delayed wound healing.

- The delay results from persistent tissue injury and inflammation

Question 5

Keloids

Answer 5

hypertrophic scars in which excessive collagenous scar tissue deposited by fibroblasts permanently extends beyond the margins of the original wound.