What do the aortic and carotid baroreceptors respond to How

What do the aortic and carotid baroreceptors respond to? How and where do they send their output?

Solution

Baroreceptors are special mechanoreceptors present in carotid sinus and aortic arch. They are pressure sensing receptors i.e, they sense the changes in pressure by checking the tension of the arterial wall. The change in pressure stretches these baroreceptors and generates impulses. They send the impulses to the nucleus of tractus solitarius and then to vasomotor center of the brain. When there is increased bllod pressure, Vasomotor center inhibits sympathetic system and increase vagal tone on the sinoatrial node of the heart. SA node is slowed by Acetylcholine, which results in decreasing heart rate. This decreased heart rate allows rectifying the pressure in arterial wall.

If there is a decrease in blood pressure, decrease in arterial wall tension would be sensed by baroreceptors and send the impulses to vasomotor center of the brain. Vasomotor center uninhibits sympathetic system and decrease vagal tone, which leads to increase in heart rate. Eventually, results in rectifying the blood pressure.