What would a change in blood pressure be detected by?

A change in blood pressure would be detected by baroreceptors. Baroreceptors are specialized sensory receptors that detect changes in blood pressure and send signals to the brain to maintain homeostasis. They are located in the carotid sinus and aortic arch, and in the heart itself. When blood pressure increases, the baroreceptors send signals to the brain to decrease heart rate and blood vessel tone, which lowers blood pressure. When blood pressure decreases, the baroreceptors send signals to the brain to increase heart rate and blood vessel tone, which raises blood pressure.