Reflex: Involuntary response to a stimulus, such as pulling your hand away from hot stove.
Rehabilitation: The process of restoring to useful life a person who has a disabling condition.
Reticular Formation: A small, thick band of neurons within the brain stem that controls breathing, blood pressure, heartbeat, levels of consciousness and other vital functions. The reticular formation constantly monitors the state of the body through its connections with sensory and motor tracts.
Retrograde Amnesia: The loss of memory of events for a period prior to the injury.