Carotid Sinus Reflexes

Carotid Sinus Reflexes


reflexes that bring about changes in arterial pressure, heart action, and respiration in response to the stimulation of nerve endings (baroreceptors or chemoreceptors) in the carotid sinus.

The carotid sinus reflexes are among the mechanisms that regulate by reflex action the constancy of arterial pressure and maintain the level of gas exchange required by the body. For example, an elevation in blood pressure stimulates the baroreceptors; then, by reflex action (through the vasomotor center and the cardioinhibitory center), it dilates the blood vessels, lowers arterial pressure, and reduces the rate of heart contractions. Changes in the gas content (a decrease in oxygen tension or increase in carbon dioxide tension) or pH of the blood excite the chemoreceptors of the carotid sinus, altering arterial pressure and the level of gas exchange. The carotid sinus reflexes are always adaptive in character, maintaining the constancy of the body’s internal environment (homeostasis).


Smirnov, A. A. Karotidnaia refleksogennaia zona. Leningrad, 1945.
Chernigovskii, V. N. Interotseptory. Moscow, 1960.