<unk>  occurs when there is not enough oxygen getting to the brain. The brain needs a constant supply of oxygen and nutrients to function.<unk>  refers to the outer part of the brain, an area called the cerebral hemisphere. However, the term is often used to refer to a lack of oxygen supply to the entire brain.
Cerebral hypoxia
Oxygen toxicity
Nitrogen narcosis
Cerebral edema
Positional asphyxia
Respiratory losses
Hypothermia
Brain ischemia