Stretch-sensitive mechanoreceptors in arterial walls detect changes in vessel wall stretch
Located mainly in the carotid sinus and aortic arch
Increased blood pressure stretches the vessel wall more
Decreased blood pressure stretches the vessel wall less
Stretch opens mechanically gated ion channels in baroreceptor nerve endings
This changes the firing rate of afferent nerves
Higher pressure increases baroreceptor firing frequency
Lower pressure decreases baroreceptor firing frequency
Signals travel via the glossopharyngeal nerve from the carotid sinus
Signals travel via the vagus nerve from the aortic arch
The brainstem interprets firing rate as a measure of blood pressure
Reflex responses adjust heart rate, contractility, and vessel diameter