The description ‘vasomotor’ refers to control of the muscular walls of blood vessels, particularly ARTERIES, dilating or constricting their diameters. The vasomotor centre is a group of neurons (see NEURON(E)) in the MEDULLA OBLONGATA of the BRAIN; they receive messages from sensory receptors in the circulatory system, and engineer reflex alterations in the heart rate and blood-vessel diameters in order to adjust the blood pressure. The centre also receives transmission from other parts of the brain, enabling emotions – fear or anger – to influence blood pressure. The vasomotor centre operates through the vasomotor nerves of the SYMPATHETIC NERVOUS SYSTEM and the PARASYMPATHETIC NERVOUS SYSTEM.