Blood Pressure is a very important aspect of homeostasis. So naturally the body has many methods of monitoring and adjusting blood pressure to keep within a range that is functional for life.
Baroreceptors are located in the aortic arch and carotid sinuses (pictured below). These are mechanoreceptors that respond to stretching of the arteries in response to blood pressure.
When these receptors are stimulated, nervous impulses are sent to the medulla oblongata of the brain where the reflex centers for vasomotor, cardiac, and respiratory are.