scar
Scars are skin lesions (fibrosis) that replace the normal skin after skin damage, and it is the result of the healing process of the creature's skin and other tissues. Thus, the scar is part of the natural healing process. In addition to very mild lesions, every wound (such as an accident, disease or after surgery) will lead to a certain degree of scars. One exception is the regeneration of the animal, does not form a scar, and the tissue will re-grow into the same as before. Scar tissue is replaced by the same protein (collagen), but the combination of fibers is different. In fibrotic tissue, collagen fibers form aligned alignment in a single direction, rather than a randomly formed basket in a normal tissue. So the scar tissue collagen fibers, functional quality is usually more poor. For example, scars on the skin are less resistant to ultraviolet radiation, and there is no sweat glands and hair follicles. Myocardial infarction, which is usually considered a major cause of heart attack, leads to the formation of myocardial scarring, which leads to loss of muscle strength and may also occur in heart failure. But there are also some organizations such as bones that can be self-healing and do not have any structural or functional deterioration. ...