Baroreceptorok

Baroreceptorok are specialized sensory receptors found in the walls of blood vessels and the heart. Their primary function is to detect changes in blood pressure. These receptors are stretch receptors, meaning they respond to the physical stretching of the vessel walls caused by blood flow.

The most important baroreceptors are located in the carotid sinuses, which are dilations in the internal carotid arteries, and in the aortic arch, the curved portion of the aorta leaving the heart. When blood pressure increases, the walls of these vessels stretch, activating the baroreceptors. Conversely, a decrease in blood pressure leads to less stretching and reduced baroreceptor activity.

The signals generated by baroreceptors are transmitted via nerves to the brainstem, specifically to the cardiovascular control centers. In response to these signals, the brainstem can reflexively adjust heart rate, contractility, and the diameter of blood vessels to help maintain blood pressure within a narrow range. This mechanism is known as the baroreceptor reflex and is crucial for short-term regulation of blood pressure, helping to buffer against sudden drops or spikes that can occur with changes in posture or activity. For example, when standing up, gravity causes blood to pool in the legs, which would lower blood pressure. The baroreceptor reflex then quickly increases heart rate and constricts blood vessels to counteract this effect and prevent fainting.