Baroreceptors in the carotid sinus detect stretch of the vessel wall and initiate reflex bradycardia. Their afferent fibres travel in the carotid sinus nerve and terminate centrally in the:
- A Nucleus of the tractus solitarius ✓
- B Hypoglossal nucleus
- C Nucleus ambiguus
- D Dorsal motor nucleus of the vagus
Correct answer: A. Nucleus of the tractus solitarius
Explanation
Carotid sinus baroreceptor afferents run in the nerve of Hering, a branch of the glossopharyngeal nerve, and their cell bodies lie in the inferior (petrosal) ganglion of CN IX. Central processes synapse in the nucleus of the tractus solitarius in the medulla, which integrates the signal and projects to the dorsal motor nucleus of the vagus and cardiovagal neurons. The dorsal motor nucleus is a parasympathetic efferent station, not the primary sensory relay, making option D the strongest distractor.
Reference: Ganong's Review of Medical Physiology, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.