The Relationship of Carbon Dioxide to Cerebral Blood Flow

The relationship of cereble blood flow to the partial pressure of oxygen is a linear one. Once you reach about 60 millimeters of mercury, that curve starts to rapidly rise away from 50 mills per hundred gram per minute. And then up at the other end, at about 80 millimeter of mercury, the curve tails off. But when you become hy poxic and your p a o two falls below 60, and definitely 50, you get a a massive rise in cerebral blood flow to try and protect the brain.