In those cases, the spread between the bid & ask goes to the market maker as compensation for making a market in a stock. For a liquid stock that is easy for the market maker to turn around and buy/sell to somebody else, the spread is small (narrow).
In cerebral hypoxia, sometimes only the oxygen supply is interrupted. Brain cells are extremely sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death.
Quick Answer. The New York University Langone Medical Center explains that brain cells begin to die after about four minutes without oxygen. Brain damage caused from a lack of oxygen is called anoxic damage, while hypoxia describes a low-oxygen condition. In other words, someone suffering from a lack of oxygen is said to be hypoxic, but any damage sustained is anoxic damage.