When do baroreceptors in the carotid artery walls and aorta respond?

The baroreceptor will start to respond when it notes some changes with the blood pressure. Baroreceptors, in general, respond to different changes in pressure so this is not a surprise. These are usually located in the aorta of the heart.

They can also be seen in the carotid arteries. Some of the largest baroreceptors can be found in the large veins and the pulmonary vessels that can be found in the lungs.

If they detect that there are some changes with the blood pressure, they will send some signals to the brain that will make the whole body feel the change. They try to make sure that the blood pressure will remain constant.