Cerebral blood flow (CBF) is the blood transfusion to the brain in a given period of time. In an adult, CBF is typically 750 millilitres per minute or 15% of the cardiac output. This compare to an average perfusion of 50 to 54 millilitres of blood per 100 grams of brain tissue per minute.An increase in hydrogen ion concentration lead to increased cerebral blood flow. A decrease in blood viscosity will increase cerebral blood flow. An increase in carbon dioxide levels results in increased cerebral blood flow.
Metabolism depends on a continuous circulatory supply of glucose and oxygen to neurons and astrocytes. In astrocytes, glucose is partly converted to lactate, which is then released in the extracellular space and taken up by neurons.With neuronal activity, lactate oxidation increases.