What is a major characteristic of an avulsion?

A major characteristic of an avulsion is that the skin is torn away from the underlying tissue. This type of injury typically results in significant damage to not just the skin but also to the deeper layers, including muscles and nerves, depending on the severity of the avulsion.

In many cases, avulsions can lead to bleeding and require medical attention to clean the wound and possibly repair the damaged tissues. Unlike other injuries, such as a surface bruise which affects only the skin's surface, an avulsion implies a more serious breach in the integrity of the skin and underlying structures. This distinction is important when assessing the severity of the injury and determining appropriate treatment.

The other options describe different types of injuries. For example, the loss of a body part can occur in severe cases of avulsion but is not a defining feature, while internal bleeding is not exclusive to avulsions and can occur due to various injuries. A surface bruise involves damage to the small blood vessels below the skin's surface and does not entail the tearing away of tissue, which is the critical aspect of an avulsion.