Baroreceptors (or baroceptors) are sensors located in the blood vessels of several mammals. They are a type of mechanoreceptor that detects the pressure of blood flowing through them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output. 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 to a normal level. They are an example of a short-term blood pressure regulation mechanism. Baroreceptors detect the amount of stretch of the blood vessel walls, and send the signal to the nervous system in response to this stretch. The nucleus tractus solitarius in the medulla oblongata recognizes changes in the firing rate of action potentials from the baroreceptors, and influences cardiac output and systemic vascular resistance through changes in the autonomic nervous system.
Baroreceptors can be divided into two categories: high-pressure arterial baroreceptors and low-pressure baroreceptors (also known as cardiopulmonary or volume receptors).