BaroreceptorsStretch receptors in the walls of the carotid sinus and aortic arch.
Glossopharyngeal nerveIt is cranial nerve IX. It carries the signals from the carotid sinus.
Vagus nerveIt is cranial nerve X. It also runs to the heart and lowers the heart rate.
Medulla oblongataThe lowest part of the brainstem. The nerves that set the heart rate start here.
Sinoatrial nodeThe pacemaker of the heart. Both sets of nerves reach it.
Negative feedbackThe response reverses the change. Here a rise in pressure ends in a fall.
The nerves 7
Carotid sinusA widening where the common carotid artery forks. It holds baroreceptors.
Aortic archThe curve of the aorta above the heart. It holds baroreceptors.
Spinal cordIt carries the sympathetic signals down from the medulla.
Sympathetic trunkA chain of ganglia beside the spinal cord. The heart's sympathetic nerves leave it.
Sympathetic nervesNerves from the sympathetic trunk to the heart. They raise the heart rate.
Cardiac plexusThe network the vagus and sympathetic nerves form at the heart.
Atrioventricular nodeThe second node of the heart's conduction system. Nerves reach it too.
How this list was compiled: Every name and every step read on 2026-10-01 and kept only where two independent sources give it. (1) Wikipedia, text only: Baroreflex, Baroreceptor, Cardiovascular centre and Heart (Nerve supply), https://en.wikipedia.org/wiki/Baroreflex and https://en.wikipedia.org/wiki/Baroreceptor : baroreceptors in the carotid sinuses and the aortic arch, the glossopharyngeal and vagus nerves, the medulla oblongata, the vagus nerve lowering and the sympathetic nerves raising the heart rate, the sympathetic trunk, the cardiac plexus, the sinoatrial and atrioventricular nodes, negative feedback. (2) Klabunde, Cardiovascular Physiology Concepts, Arterial Baroreceptors and Autonomic Innervation of the Heart and Vasculature, https://cvphysiology.com/blood-pressure/bp012 and https://cvphysiology.com/blood-pressure/bp008 : the same receptors, nerves and medulla, the sympathetic path down the spinal cord and through the ganglia, and the nodes the nerves reach. (3) Gray's Anatomy (1918, public domain), The Heart, https://theodora.com/anatomy/the_heart.html : the cardiac plexus, formed from the vagi and the sympathetic trunks. The layout and the words in the boxes are our own. Licence: own work
The drawing: Drawn for this site on 2026-10-01 from plain geometry. Own original chart and drawing; nothing traced or copied. Licence: own work
How it works
The first chart is a heart rate negative feedback diagram: each box says what happens, and the name of the structure is blank. The second is an innervation of the heart diagram, with the nerves drawn as lines.
Read the full guide
The loop
Start at Blood pressure rises and follow the arrows. Stretch sensors in two arteries report to a control center in the brainstem, which slows the heart's pacemaker. Heart rate and blood pressure fall back, so the loop is negative feedback. When pressure falls, the same loop speeds the heart up.
The nerves
Solid lines are the glossopharyngeal nerve, from the carotid sinus, and the vagus nerve, which runs down to the heart. Dashed lines are sympathetic nerves from the sympathetic trunk beside the spinal cord. They meet in the cardiac plexus.
The vagus nerve lowers the heart rate; the sympathetic nerves raise it.
Questions and answers
How is heart rate controlled by negative feedback?
Baroreceptors in the carotid sinus and aortic arch sense a rise in blood pressure and signal the medulla oblongata. It sends more signals down the vagus nerve and fewer down the sympathetic nerves, the heart rate falls, and blood pressure falls back.
Which nerves control the heart rate?
The vagus nerve, which is parasympathetic, lowers the heart rate. Sympathetic nerves from the sympathetic trunk raise it. Both reach the sinoatrial and atrioventricular nodes, and together they form a network at the heart called the cardiac plexus.
Where are the baroreceptors?
The arterial baroreceptors are in the carotid sinus, where the common carotid artery forks in the neck, and in the aortic arch. They are stretch receptors: they fire faster when higher pressure stretches the artery wall.
What is the control center for heart rate?
The medulla oblongata, the lowest part of the brainstem. Signals from the baroreceptors arrive there, and the nerves that change the heart rate start from it. Its region for this is called the cardiovascular center.