Cerebral circulation is the movement of
blood through the network of
blood vessels supplying the
brain. The rate of the
cerebral blood flow in the adult, is typically 750
milliliters per minute, representing 15% of the
cardiac output. The
arteries deliver oxygenated blood,
glucose and other nutrients to the brain and the
veins carry deoxygenated blood back to the
heart, removing
carbon dioxide,
lactic acid, and other metabolic products. Since the brain is very vulnerable to compromises in its blood supply, the cerebral circulatory system has many safeguards. Failure of these safeguards results in
cerebrovascular accidents, commonly known as
strokes. The amount of blood that the cerebral circulation carries is known as
cerebral blood flow. The presence of gravitational fields or accelerations also determine variations in the movement and distribution of blood in the brain, such as when suspended upside-down.