Final answer:
An abrasion or scratch mark is a form of self-induced erosion on the skin. It occurs when the skin is subjected to constant friction or mechanical stress, leading to the removal of the top layer of skin cells. Calluses and corns are examples of abrasions that form on areas of the skin exposed to prolonged pressure or repetitive motion.
Step-by-step explanation:
An abrasion or scratch mark is a form of self-induced erosion on the skin. It occurs when the skin is subjected to constant friction or mechanical stress, leading to the removal of the top layer of skin cells. Calluses and corns are examples of abrasions that form on areas of the skin exposed to prolonged pressure or repetitive motion. These abrasions serve as a protective mechanism for the body, as they increase the thickness of the skin to prevent further damage.