<P> Baroreceptors (or archaically, pressoreceptors) are sensors located in the blood vessels of all vertebrate animals . They sense the blood pressure and relay the information to the brain, so that a proper blood pressure can be maintained . </P> <P> 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 total peripheral resistance . Baroreceptors act immediately as part of a negative feedback system called the baroreflex, 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 . </P> <P> 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 or volume receptors). </P> <P> Arterial baroreceptors are stretch receptors that are stimulated by distortion of the arterial wall when pressure changes . The baroreceptors can identify the changes in both the average blood pressure or the rate of change in pressure with each arterial pulse . Action potentials triggered in the baroreceptor ending are then directly conducted to the brainstem where central terminations (synapses) transmit this information to neurons within the solitary nucleus . Reflex responses from such baroreceptor activity can trigger increases or decreases in the heart rate . Arterial baroreceptor sensory endings are simple, splayed nerve endings that lie in the tunica adventitia of the artery . An increase in the mean arterial pressure increases depolarization of these sensory endings, which results in action potentials . These action potentials are conducted to the solitary nucleus in the central nervous system by axons and have a reflex effect on the cardiovascular system through autonomic neurons . Hormone secretions that target the heart and blood vessels are affected by the stimulation of baroreceptors . </P>

Where are the baroreceptors that monitor blood pressure located