The reactivity of cerebral vessels by hypoxia and hypercapnia in patients the second coming of age

Atinfluence of an increasing hypoxia, changing of a cerebral blood flow depend on the size of incentive and on age of examinees. Decrease of the content of oxygen in an inhaled gas admixture to 13–15 % leads to rising of a tonus of intracranial vessels and blood flow decrease. Ataugmentation of a hypoxemic load (8–10 %) the cerebral blood flow increases. The hypocapnia causes risings of a tonus of arterioles, venules and microvessels that leads to decrease of a pulseкровенаполнение and augmentation of peripheric resistance against a tendency of venous outflow to dropping.