Smarter Brains Are Bloodthirsty Brains (IMAGE) University of Adelaide Caption These are human skulls, showing the location of two openings for the internal carotid arteries that supply the cerebrum of the brain almost entirely. The sizes of these openings reveal the rate of blood flow, which is related to brain metabolic rate and cognitive ability. Credit Photo credit: Edward Snelling. Sourced from the Raymond Dart Collection of Human Skeletons, School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand. Usage Restrictions For use with this story License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.