THE REGULATION OF CEREBRAL CIRCULATION

The normal function of the central nervous system requires a constant milieu for its nerve cells which are extremely dependent upon a delicate regulation of their ionic environment and upon a constant and high supply of oxygen and nutrients. The milieu of the central nervous system is to a great extent determined by the cerebral circulation which by a number of mechanisms is kept fairly constant in spite of substantial alterations of the blood flow within other sectors of the systemic circulation. The homeostasis of the milieu of the brain, including its circulation, is ultimately an expression of the global importance of this organ which, according to BAYLISS, is so great that the cerebral circulation “is regulated by the rest of the body.”