The average adult brain weight just under 3 pounds(between 1.3 and 1.4 kilograms).Some neurosurgeons describe the texture of a living brain as that of toothpaste.If you were to blend up all of that brain,blood and fluid,it would come to about 1.7 liter,or not quite enough to fill a 2 liter soda bottle.Brain uses about 20 percent of the oxygen in our blood and 25 percent of the glucose(sugars)circulating in our bloodstream.