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.
3. How long can the brain go without oxygen before serious damage occurs? After five to ten minutes of not breathing, you are likely to develop serious and possibly irreversible brain damage. The one exception is when a younger person stops breathing and also becomes very cold at the same time. This can occur when a child is suddenly plunged into very cold water and drowns. In this situation, survival after more than 30 minutes has been known to occur. Return to the list of Frequently Asked Questions >>