From the Guidelines
The glossopharyngeal nerve (CN IX) and vagus nerve (CN X) control baroreceptors.
Key Points
- The glossopharyngeal nerve (CN IX) is responsible for visceral sensory innervation to the carotid sinus, which plays a role in regulating circulation 1.
- The vagus nerve (CN X) also has a role in regulating circulation, with its branchial motor branches innervating muscles of the pharynx and larynx, and its visceral motor branches playing a role in parasympathetic supply to the thorax and abdomen 1.
- Both nerves are involved in the regulation of blood pressure and are therefore important in the control of baroreceptors.
- The glossopharyngeal nerve (CN IX) and vagus nerve (CN X) arise from the medulla oblongata and traverse the jugular foramen in the posterior skull base before extending into the neck 1.
- Lesions affecting these nerves, such as tumors, infections, or trauma, can lead to abnormalities in blood pressure regulation and other symptoms 1.
From the Research
Cranial Nerves Controlling Baroreceptors
The cranial nerves that control baroreceptors are:
- The glossopharyngeal nerve, which provides sensory inputs from baroreceptors at the carotid sinus 2, 3, 4
- The vagus nerve, which provides sensory inputs from baroreceptors in different reflexogenic areas including the aortic arch, atria, ventricles, and pulmonary arteries 2, 3
Baroreceptor Locations and Functions
Baroreceptors are located in various areas, including:
- The carotid sinus, which is innervated by the glossopharyngeal nerve via the carotid sinus nerve (CSN) 3, 4
- The aortic arch, which is innervated by the vagus nerve 2, 5
- The atria, ventricles, and pulmonary arteries, which are also innervated by the vagus nerve 2
Integration of Baroreceptor Signals
The signals from these baroreceptors are integrated in the nucleus tractus solitarius, which is located in the medulla 2, 3, 4 The integrated signals are then used to regulate sympathetic and parasympathetic activity, which in turn controls blood pressure and heart rate 2, 5, 6