Baroreceptor

Baroreceptors (or archaically, pressoreceptors) are sensors located in the carotid sinus (at the bifurcation of common carotid artery into external and internal carotids) and in the aortic arch.^[1] They sense the blood pressure and relay the information to the brain, so that a proper blood pressure can be maintained.

Baroreceptors are a type of mechanoreceptor sensory neuron that are excited by a stretch of the blood vessel. Thus, increases in the pressure of blood vessel triggers increased action potential generation rates and provides information to the central nervous system. This sensory information is used primarily in autonomic reflexes that in turn influence the heart cardiac output and vascular smooth muscle to influence vascular resistance.^[2] Baroreceptors act immediately as part of a negative feedback system called the baroreflex,^[3] as soon as there is a change from the usual mean arterial blood pressure, returning the pressure toward a normal level. These reflexes help regulate short-term blood pressure. The solitary nucleus in the medulla oblongata of the brain recognizes changes in the firing rate of action potentials from the baroreceptors, and influences cardiac output and systemic vascular resistance.

Baroreceptors can be divided into two categories based on the type of blood vessel in which they are located: high-pressure arterial baroreceptors and low-pressure baroreceptors (also known as cardiopulmonary^[4] or volume receptors^[5]).