Which term best describes a wound that has been injured but not exposed to external contaminants?

The term that best describes a wound that has been injured but not exposed to external contaminants is a contusion. A contusion occurs when the small blood vessels under the skin are damaged due to a direct blow, leading to bruising and swelling without breaking the skin. This type of wound remains closed and is generally not exposed to external elements, which makes it distinct from other types of wounds.

In contrast, a contaminated wound refers specifically to injuries that have been exposed to bacteria or other contaminants, and therefore does not fit the criteria of being unexposed. A closed wound is a broader term that may include contusions as well, but it doesn't specifically denote the characteristics of the injury itself, such as the bruising associated with a contusion. An open wound, on the other hand, denotes an injury that breaks the skin and directly exposes underlying tissues to the external environment, which contradicts the definition of being free from external contamination.