What defines a contusion?

A contusion is defined as a closed injury that occurs when small blood vessels in the skin and underlying tissues break due to some form of trauma, leading to bleeding beneath the skin. This results in a characteristic discoloration often referred to as a bruise. Since a contusion does not involve an open wound, it is accurately described by the first choice, which states it is a closed injury affecting the dermis, thereby indicating impact without skin laceration. The other options describe different types of injuries or wounds that do not capture the essence of a contusion.