Answer
Some impulses that reach the cardiovascular center (CV center) travel from baroreceptors in the cardiac sinus by way of the glossopharyngeal nerve (CN IX). Impulses from baroreceptors in the arch of the aorta also travel to the CV center, but their route is through the vagus nerve (CN X).
Work Step by Step
When there are changes in blood pressure, baroreceptors in the cardiac sinus, and in the arch of the aorta transmit impulses to the CV center to inform it of the changes. The CV center regulates changes in cardiovascular parameters ( BP, HR etc) by sympathetic and parasympathetic outputs. If, for instance, there is a fall in BP, the stretch of the baroreceptors will decrease ,and they will transmit impulses at a slower rate to the CV center. The CV center would respond by increasing sympathetic stimulation via cardioacceleratory neurons, and decreasing parasympathetic stimulation via vagus neurons. Some consequences of these activities of the CV center would be increases in blood pressure, cardiac output (CO), and heart rate (HR). Increase in heart rate and some other responses would be significantly enhanced by the release of norepinephrine and epinephrine from the adrenal medulla under the influence of sympathetic stimulation.
