Arterial and venous cerebral blood flow responses to long‐term head‐down bed rest in male volunteers

Abstract

What is the central question of this study? A heterogeneous cerebral blood flow (CBF) response in the cerebral arteries has been demonstrated in several physiological conditions, and it might be attributable to different physiological properties. However, the whole cerebral haemodynamic response to weightlessness remains unknown. What is the main finding and its importance? Long‐term head‐down bed rest caused a heterogeneous CBF response between the anterior and posterior cerebral arteries and between the cerebral arteries and veins. Especially, in contrast to the anterior cerebral circulation, the posterior arterial and venous CBFs were well maintained throughout weightlessness.