As a medical professional with expertise in neurology and critical care, I can provide insight into the concept of brain death and its relationship to respiratory function. Brain death is the irreversible cessation of all functions of the entire brain, including the brainstem. The brainstem is the part of the brain that controls many vital functions, including the respiratory drive. When a person is declared brain dead, it means that there is no possibility of recovery, and all brain functions have permanently stopped. Under normal circumstances, if the brain is functioning, it sends signals to the muscles that control breathing. However, when a person is brain dead, these signals cease, and the individual would not be able to breathe on their own without the assistance of a ventilator or breathing machine. It is true that the heart can continue to beat for some time after the brain has ceased functioning, but this is typically only possible when breathing is artificially maintained. This is because the heart can continue to function for a short period without the brain's direct control due to the presence of an automatic electrical system within the heart itself. However, without the brain to regulate the body's vital functions, including the respiratory drive, the body cannot sustain life, and eventually, the heart will stop as well. In summary, a person who is brain dead cannot breathe on their own and would require mechanical ventilation to maintain breathing. The heart may continue to beat for a time after the brain has ceased functioning, but without the brain's regulation, the body cannot survive. read more >>

When the breathing machine is turned off, a patient who is brain dead will not breathe. The heart will beat for some time after the brain dies as long as breathing is artificially maintained because heart function is not entirely dependant on the brain.read more >>