What are baroreceptors?

Baroreceptors are specialized sensors located in the walls of blood vessels, particularly in the carotid arteries and the aorta. Their primary function is to detect changes in blood pressure. When blood pressure rises, baroreceptors stretch and send signals to the central nervous system, particularly the brainstem, which then triggers mechanisms to lower blood pressure, such as decreasing heart rate or dilating blood vessels. Conversely, when blood pressure drops, baroreceptors sense this change and initiate responses to increase blood pressure, ensuring that blood flow remains stable and adequate throughout the body.

The other options refer to entirely different physiological functions. Insulin is produced by pancreatic cells, which are not related to blood pressure regulation. Sensors that regulate sleep patterns relate to circadian rhythms and are not involved in cardiovascular function. Neurons that control heart rhythm are part of the cardiac conduction system, but they do not serve the role of monitoring and responding to blood pressure like baroreceptors do. Thus, the correct answer highlights the crucial role of baroreceptors in maintaining blood pressure homeostasis.