Baroreceptors are specialized sensory nerve endings located primarily in the walls of blood vessels, particularly in the carotid arteries and the aorta. They play a crucial role in monitoring blood pressure by detecting changes in the stretch of the vessel walls. When blood pressure rises, the baroreceptors are activated and send signals to the brain to help regulate heart rate and blood vessel diameter. These receptors are part of the body's feedback system for maintaining stable blood pressure. When blood pressure drops, baroreceptors decrease their signaling, prompting the body to respond by increasing heart rate and constricting blood vessels. This process helps ensure that vital organs receive adequate blood flow.