Baroreceptors are most sensitive to changes in what?

Baroreceptors are specialized mechanoreceptors located primarily in the walls of blood vessels such as the carotid arteries and the aortic arch. Their primary function is to detect changes in blood pressure. When blood pressure rises, baroreceptors are stretched, and they send increased signals to the central nervous system indicating that the pressure is higher than normal. Conversely, if blood pressure drops, the stretching decreases, and the frequency of signals decreases as well. This sensory feedback is critical for the regulation of blood pressure through reflexive pathways that modulate heart rate and vascular resistance, helping to maintain homeostasis.

While other factors such as blood volume, heart rate, and blood oxygen levels can influence cardiovascular function, it is the direct measurement of blood pressure changes that primarily drives the baroreceptors' activity. Thus, sensitivity to blood pressure changes is what enables the cardiovascular system to react swiftly to maintain stability during various physiological states.