What constitutes the primary difference between abrasions and incisions?

The primary difference between abrasions and incisions lies in the wound depth. Abrasions are superficial injuries that affect only the outer layers of the skin (epidermis and possibly the upper portion of the dermis), resulting from friction or scraping against a rough surface. In contrast, incisions are cuts made by sharp objects, such as knives or glass, which penetrate deeper into the skin and can damage underlying structures, including deeper layers of the dermis and potentially even muscles or other tissues.

While the type of object used can contribute to the classification of the wound (sharp for incisions, blunt for abrasions), it is not the fundamental distinction. Similarly, severity can vary widely in both types of wounds depending on various factors, and surrounding tissue damage is usually more relevant to how deep and severe a wound is but does not define the fundamental nature of abrasions versus incisions. Thus, depth is the primary characteristic that differentiates these two types of injuries.