How long can the brain go without oxygen to where you wont wake up?
The brain can survive for up to about six minutes after the heart stops. The reason to learn cardiopulmonary resuscitation (CPR) is that if CPR is started within six minutes of cardiac arrest, the brain may survive the lack of oxygen. After about six minutes without CPR, however, the brain begins to die.
SOMETIMES at random times when i smoke weed my vision will get spotty and then go completely black and i will get super heavy pass out wake up my vision will clear up and i will feel really high?
You are probably just accustomed to it -- if you have been snoring for a long time your brain has learned that it is ok to keep sleeping through the sound of your snoring. It is possible that your snoring does wake you up sometimes but that you don't realize that it is the snoring that woke you up -- don't forget, you stop snoring when you wake up.
Unless your bladder is really full, the need to pee doesn't interfere with your need to sleep. When you wake up, your brain realizes that it now needs to pee. Sometimes you need to go so urgently that you wake up anyway. Your bladder is screaming, "WAKE UP! WAKE UP!". But for some people, their brain doesn't hear this desperate cry for help. And those people wake up to a damp bed.
it is believed to be a way for the body to bring in more oxygen and rid itself of load of carbon dioxide. Other theories suggest that we yawn to wake up, or to induce relaxation. Read more at Suite101: Yawning and Brain Health: A Yawn Provides Oxygen, Stimulates Brain, Helps in Changing Energy http://naturalmedicine.suite101.com/article.cfm/yawning_and_brain_health#ixzz0fTPYZXqW