Values of global and regional cerebral blood flow, received in experimental and clinical investigation as the informative criteria for brain blood supply, are often misleading.Although it is known, that an increase of brain activity to be accompanied by a rise of blood flow in activated regions, while a decreased activity results in a decreased blood flow, which demonstrates the presence of close interaction between the brain blood supply and its activity.The correlation between the brain blood supply and its functional activities is not proven in all cases.Such a correlation had not been noted in the age-dependent decrease of cerebral blood flow, as well as at some pathophysiological cases.These are suggesting the existence of special age-related mechanisms, based on integrations of cerebrovascular and CSF circulatory systems, that develop with age to maintain brain metabolism.Significant role at this process may play the biomechanical properties of the skull as united structural-functional organization, which permits to accept additional blood volume by skull during systolic increase arterial pressure.However, only recently mechanisms of circulatory support of brain activity were validated by the simultaneous recording of Transcranial Dopplerogram and Rheoencephalogram with computer aid analysis, focused on single cardiac cycles, recorded under different conditions-as response to functional tests, in age aspect and at some pathophysiological cases.It was shown also the functioning integration of the intracranial blood and cerebrospinal fluid dynamics with brain cognitive function, determined by special physiological computer aid methods.This is confirmed by the presence of correlation of the circulatory-metabolic support of brain activity and changing its cognitive function, special for aging population with initial and moderate dementia.Received data permits to create a conceptual model of adequate circulatory-metabolic supply of brain activity, showing the functional unity, which follows from integration of the functioning the of brain blood flow, SCF circulation, biomechanical properties of the skull and peculiarities of volume-pressure relations of liquid media inside skull.Final result of this model to understood mechanism, which is support adequate brain activity under different living situations.