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.
Though COPD hypoxia makes breathing difficult, it affects more than just the lungs. When you canât breathe in enough oxygen, your blood is deprived of a vital component. Oxygen is essential to carrying out basic body functions. For example, hypoxia can have serious effects on your heart and brain health. COPD hypoxia can lead to a condition called cerebral hypoxia. This type of hypoxia occurs when the brain lacks oxygen even though itâs getting enough blood. If you experience cerebral hypoxia, your brain cells can start dying within five minutes, according to the National Institute of Neurological Disorders and Stroke.