Arterial baroreceptors function to inform the autonomic nervous system of beat to beat changes in blood pressure within the arterial system. Rapid decreases in blood pressure, such as in times of orthostatic hypertension result in decreased stretching of the artery wall and decreased action potential frequency which ultimately results in increased cardiac output and vasoconstriction resulting in increased blood pressure. The opposite is found to be true of increased blood pressure.

Cardiopulmonary receptors, or volume receptors, are similarly mechanoreceptors that function to inform the autonomic nervous system of the blood volume within the system. In low volume states, circulatory and renal changes result in increased salt and water resorption within the kidneys, increased salt and water oral intake, and slower, longer-term changes in mean pressure.[8]

One study showed that the carotid baroreceptor reflex could regulate cerebral blood flow at rest and during dynamic exercise. This study was small, with only seven subjects around the age of 26. It found that with heavy exercise middle cerebral artery blood flow with tripled and cerebral tissue oxygenation was almost tripled, but prazosin was able to blunt the mean arterial pressure, cerebral oxygenation, and cerebral blood flow during exercise and at rest. Prazosin is a sympatholytic medication and an alpha-1 blocker resulting in vascular smooth muscle relaxation. The choice of this drug was due to the vascular smooth musculature found in the carotid sinus, carotid body, and cerebral vasculature.

Another small study with only 8 participants, found that group III/IV afferent muscle fibers are critical in resetting the carotid baroreflex mean arterial pressure and heart rate operating points despite changes induced by exercise when a subject is in command of the spontaneous movements.[9]

Cardiopulmonary receptors have strong associations with body position changes and with activation evoke sympathoinhibition demonstrated by a small study of 13 healthy men around the age of 21 showing increase in heart rate, stroke volume, and cardiac output when subjects are in seated positions as opposed to no changes while in the supine position. These changes are blunted to statistical insignificance with a beta-1 adrenergic blockade, such as with atenolol, demonstrating the sympathetic mediation of cardiac responses.

Baroreceptor exerts control of mean arterial pressure as a negative feedback loop. Nerve impulses from arterial baroreceptors are tonically active; increases in arterial blood pressure will result in an increased rate of impulse firing. Increased stimulation of the nucleus tractus solitarius by arterial baroreceptors results in increased inhibition of the tonically active sympathetic outflow to peripheral vasculature, resulting in vasodilation and decreased peripheral vascular resistance. The opposite is true of decreases in mean arterial pressure, which results in decreased nerve firing and reduced stimulation of the nucleus tractus solitarius thereby attenuating inhibition and increasing sympathetic outflow to peripheral vasculature and vasoconstriction.

Similarly, nerve impulses from cardiopulmonary baroreceptors are also tonically active and increase their rate of firing secondary to increased blood volume and mean arterial pressure results in decreased sympathetic outflow to the sinoatrial node and decreased heart rate and cardiac output. In a notable difference, sympathetic outflow to the kidney increases which increases renal blood flow and urine production, thereby decreasing the fluid volume of the body.[10]

Baroreceptor resetting has been implicated in maintenance of inappropriately elevated mean arterial pressures, while on the opposite end of the spectrum, carotid sinus syndrome is a syndrome in which the carotid sinus is particularly sensitive to external pressure. Increased pressure on the carotid sinus, such as from a particularly tight collar or sustained turn of the head, results in significant hypotension and possibly syncope.[11][12]

Carotid sinus sensitivity can result in syncope with stimulation of the carotid sinus externally, such as with shaving.

Carotid sinus massage with terminate approximately 20% of episodes of re-entry supraventricular tachycardia. This vagal maneuver should be avoided or used with caution in the elderly as atherosclerotic plaque formations might be disrupted and strokes may occur.[13]

There have been propositions made for surgical procedures for the treatments of carotid sinus syndrome, heart failure, hypertension, and insulin resistance. The proposals would be denervation of the carotid sinus for carotid sinus syndrome and carotid body removal for refractory hypertension and heart failure. It has also been suggested to produce baroreceptor electrical stimulation for refractory hypertension and heart failure.

A case study has found that head and neck radiation for the treatment of squamous cell carcinoma of the tongue resulted in orthostatic hypotension due to baroreceptor failure.