A head injury in which the brain has been affected but the skin is still intact is known as what?

A head injury where the brain has been impacted while the outer layer of skin remains intact is referred to as a closed head injury. In this type of injury, the protective layers of the scalp and skull are not breached, meaning there is no direct exposure of brain tissue to the environment. This distinction is significant because closed head injuries can still result in various types of brain damage, such as contusions, concussions, or diffuse axonal injuries, without necessarily causing an open wound.

In contrast, an open head injury involves a break in the skull and exposure of brain tissue, which typically poses a higher risk of infection and more severe outcomes. The term "concussion" specifically refers to a functional disruption of the brain usually caused by a blunt force or shake, but it does not encompass the entire spectrum of brain injury types. A skull fracture refers to a break in the bony structure of the skull, which does not automatically indicate whether the injury is open or closed. Thus, the choice indicating a closed head injury accurately describes the situation where brain damage occurs without an external wound, capturing the essence of the injury's nature.