the brain needs oxygen

A person can make the choice to not breathe, a breath can’t be held in forever. The time taken between breathes can be lengthened, for example – swimmers or singers, but in the end the brain if it is healthy and intact will force the body to take a breath. The brain is very sensitive to oxygen deprivation; it requires ten times more oxygen than any other organ. Try to deprive it and it will seize control. When a breath is help in the carbon dioxide levels rise in the body and a reflex is triggered by the cerebral cortex the overrides the medulla and causes the rib muscles to spasm. The spasm is very painful and it hard to ignore, resulting in a person gasping for air. If the person manages to get through the spasm the brain has a plan B, unconsciousness. Without awareness the person is unable to control the breathing process. Because of this breathing is reverted to the automatic nervous system, and breathing Is restored quickly. The process of unconsciousness has yet to be determined fully, it is known that the reticular activating system (RAS) located in the brainstem controls the ability of alertness, sleep and attention span. Oxygen deprivation to the brain can affect the RAS system, causing the person to become unconscious. Could unconsciousness be the brains way of survival mode?