Sensorium: The totality of those parts of the brain that receive, process and interpret sensory stimuli. The sensorium is the supposed seat of sensation, the place to which impressions from the external world are conveyed and perceived.
The sensorium also refers to the entire sensory apparatus of the body.
In medicine, "sensorium" is sometimes used as a generic term for the intellectual and cognitive functions. For example: "A 77-year old woman with cirrhosis was admitted (to the hospital) with a one-week history of altered sensorium." (New Engl J Med 343: 1933, 2000)
The term "sensorium" comes (as does the word "sensation") from the Latin sensus, "the faculty of perceiving." The plural of "sensorium" is rarely used but in case of need you can choose between "sensoriums" and "sensoria."