This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Factors influencing wound healing are the following: \nSelect and explain. \nA. Nutrition, B. Adequate blood supply, C. Size and location of wound, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Factors That Impair Tissue Repair\xa0\nTissue repair may be impaired by a variety of factors that reduce the quality or adequacy of the reparative process. Factors that interfere with healing may be extrinsic (e.g., infection) or intrinsic to the injured tissue, and systemic or local:\n\nInfection is one of the most important causes of delayed healing; it prolongs inflammation and potentially increases the local tissue injury.\nDiabetes is a metabolic disease that compromises tissue repair for many reasons, and is an important systemic cause of abnormal wound healing.\nNutritional status has profound effects on repair; protein malnutrition and vitamin C deficiency, for example, inhibit collagen synthesis and retard healing.\nGlucocorticoids (steroids) have well-documented anti-inflammatory effects, and their administration may result in weak scars\xa0because they inhibit TGF-β\xa0production and diminish fibrosis. In some instances, however, the anti-inflammatory effects of glucocorticoids are desirable. For example, in corneal infections, glucocorticoids may be prescribed (along with antibiotics) to reduce the likelihood of opacity due to collagen deposition.\nMechanical factors such as increased local pressure or torsion may cause wounds to pull apart (dehisce).\nPoor perfusion, resulting either from arteriosclerosis and diabetes or from obstructed venous drainage (e.g., in varicose veins), also impairs healing.\nForeign bodies such as fragments of steel, glass, or even bone impede healing.\nThe type and extent of tissue injury affects subsequent repair. Complete restoration can occur only in tissues composed of cells capable of proliferating: even then, an extensive injury will probably result in incomplete tissue regeneration and at least partial loss of function. Injury to tissues composed of non-dividing cells must inevitably result in scarring; such is the case with healing of a myocardial infarct.\nThe location of the injury and the character of the tissue in which the injury occurs also are important.\n\n\xa0 \xa0\xa0Robins 10 th ed page no 93', 'role': 'assistant'}]