<P> The vasomotor center ( VMC ) is a portion of the medulla oblongata that , together with the cardiovascular center and respiratory center , regulates blood pressure and other homeostatic processes . Vasomotor center is a fairly archaic term since this function relies not on a single brain structure ( `` center '' ) but rather represents a presympathetic network of interacting neurons . Upon increase in carbon dioxide level at central chemoreceptors , it stimulates the sympathetic system to constrict vessels . This is opposite to carbon dioxide in tissues causing vasodilatation , especially in the brain . Cranial nerves IX ( Glossopharyngeal nerve ) and X Vagus nerve both feed into the vasomotor centre and are themselves involved in the regulation of blood pressure . The localization of VMC was determined by Filipp Ovsyannikov in 1871 . </P>
where are the cardiac and vasomotor centers found
medulla oblongata