Hi, Thanks for writing in. Technically speaking the brain is the center for controlling all functions in the body. This includes important effects like wakefulness, breathing, heart beats, digestion, mobility and many other functions, The moment a person is supposed to be brain dead, the other organs are made function using artificial methods. This means the persons brain is actually not doing any work but the rest of the functions are being taken care of artificially. The heart and lungs are connected to the ventilator. The kidneys are connected to dialysis and the persons vital functions are extended. In this way, if proper care is given, the patient can stay without any further complications for up to a week under normal circumstances and then the ventilator is cut off. However under special circumstances and with legal support, brain dead individuals have been maintained for a month on life support.