Capillary embryonic development new capillaries are formed through vasculogenesis, the process of blood vessel formation that occurs through a "de novo" production of endothelial cells which then form vascular tubes. The term angiogenesis denotes the formation of new capillaries from pre-existing blood vessels and already present endothelium which divides. Blood flows from the heart through arteries, which branch and narrow into arterioles, and then branch further into capillaries where nutrients and wastes are exchanged. The capillaries then join and widen to become venules, which in turn widen and converge to become veins, which then return blood back to the heart through
Cerebral circulation Cerebral circulation Cerebral circulation is the movement of blood through the network of cerebral arteries and veins 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 including autoregulation of the blood vessels and the