Picture of Baroreceptors
The body has mechanisms to alter or maintain blood pressure by specialized nerve cells called baroreceptors. These sensors, found in the large arteries closest to your heart, sense blood pressure and then send signals to the heart, the arteries, the veins, and the kidneys that cause them to make changes that regulate blood pressure. The goal is to maintain cardiac output, the amount of blood delivered to organs in the body.
Image Source: MedicineNet
Text: "Understanding Low Blood Pressure - Symptoms", WebMD