This is known as the vasodilator center, and it acts in opposition to the vasoconstrictor.
The tone of the vasoconstrictor center controls the distribution of blood throughout the body.
For some reason or other the vasoconstrictor center becomes inactive, and the series of events just described is set in motion.
The nervous center which brings this about is called vasomotor, or, more properly, the vasoconstrictor center.
Not all the blood vessels in the body are acted upon through the vasoconstrictor center.
vasoconstrictor va·so·con·stric·tor (vā'zō-kən-strĭk'tər)
Something, such as a nerve or drug, that causes vasoconstriction. adj.