The answer is STOMACH. If the brain stem malfunctions, then the body will be deprived of nutrients. So the brain stem is needed, not the brain itself. The stomach is in charge of the digestion of food, if there is a malfunction, the movement of nutrients is affected. There is a disorder which i do not recall in which babies are born without brains, but only brain stems and these babies do not have any problems with the absorption or deprivation of nutrients. Hope i helped, have a nice day.
