nervous system process involved in regulation of systemic arterial blood pressure regulation of systemic arterial blood pressure by ischemic conditions biological_process CNS ischemic response GO:0001980 ischemic regulation of systemic arterial blood pressure ischemic control of blood pressure The process that modulates blood pressure by the detection of carbon dioxide levels in the brain stem. Increased levels activate the sympathetic vasoconstrictor mechanism increasing the force with which blood flows through the circulatory system.