Contrary to what drug makers would have you believe, your blood pressure is not regulated by chemicals in the blood. Individuals with normal blood pressure do not have higher levels of Lipitor in their bodies. In fact, the chemicals sold to artificially reduce blood pressure do not occur naturally in the body.
Our blood pressure is regulated from moment to moment by nerves. At specific locations in the walls of the large arteries, special sensors “measure” blood pressure by responding to the amount of stretch in the walls of the arteries, monitoring oxygen and carbon dioxide levels in the blood, and relaying information about the stretching of the heart's chambers (which is a function of circulating blood volume).
When blood pressure increases for any reason, these sensors send nerve signals to the blood pressure regulating center located in the lower portion of the brain. In response to the nerve signals, the blood pressure regulating center sends out nerve signals that slow the heart and dilate the arterioles. The lower output of blood by the heart and the lower peripheral resistance to blood flow results in lowering the arterial blood pressure back toward normal.
An example of this reflex occurs when you suddenly sit or stand up after lying down. Gravity pulls the blood downward, lowering the blood pressure in the carotid sinus in your neck. If the carotid sinus reflex didn’t act promptly, sending out nerve impulses (over sympathetic nerves) to increase heart output and constrict the arterioles, you would faint from the decreased flow of blood to your head.
This same process is in effect during the “fight or flight response”. The sympathetic nervous system is the portion of the autonomic (involuntary) nervous system that has as its main function the preparation of our bodies for emergency situations. The sympathetic (adrenergic) nervous system sends nerve signals to the blood pressure regulating center of the brain, telling it to raise the blood pressure, which the center accomplishes by sending signals over sympathetic nerves that go to the heart and blood vessels.
The brain communicates with the heart and arteries in a manner like that of interactive communication between networked computers. Sensory nerves in the heart and arteries carry information to the brain. These nerves run through the spine and pass through small openings called foramen. Information is transmitted from the brain back to the heart and arteries over this same pathway. Interference with these control signals can often be the result of neuropathy (changes in nerve pathology) caused by misalignment of the vertebrae that house and protect these delicate nerves, particularly the first vertebrae or atlas.
Correcting the underlying cause, vertebral misalignment, with chiropractic adjustments can restore proper communication between the brain and the heart and arteries, reducing blood pressure and often eliminating the need for blood pressure regulating drugs, according to several recently released placebo controlled studies.