The Glucose Pool In Health	

The size of the glucose pool is normally tightly controlled by a number of quasi-independent homeostatic mechanisms that are co-ordinated by a hypothetical master centre (Fig. 20.2).
Although the exact size of the glucose pool is determined by both the volume of extracellular fluid and its glucose concentration, in practice it is only the latter that varies. The glucose pool rarely exceeds 27g (0.l5mol) even after ingestion of a meal containing up to 360g (2mol) of glucose in the form of starch, and it does not shrink below 13g (0.075mol) even after prolonged fasting. 

See later:
• Fuel Consumption by the Brain