Visceral Sensory

Overview

The visceral sensory component of CN X provides sensory information from the larynx, esophagus, trachea, and abdominal and thoracic viscera, as well as the stretch receptors of the aortic arch and chemoreceptors of the aortic bodies.

Peripheral Course

Sensory fibers from the plexuses surrounding the abdominal viscera converge and join the gastric nerves which ascend through the esophageal hiatus of the diaphragm and merge with the esophageal plexus.

In the thorax, visceral sensory fibers from the heart and lungs also join the ascending fibers in the esophageal plexus which converge to form the left and right vagus nerves which ascend within the carotid sheath between the internal jugular vein and internal carotid artery.

Visceral sensory fibers from the larynx and pharynx join the ascending vagal fibers via the internal laryngeal and recurrent laryngeal nerves.

The cell bodies of these afferent neurons reside in the inferior vagal ganglion in the jugular foramen.

Central Course

The central processes of the visceral sensory neurons pass from the inferior vagal ganglion through the jugular foramen and enter the medulla. These fibers descend in the tractus solitarius to synapse in the caudal nucleus solitarius.

From the nucleus solitarius, bilateral projections to several areas in the reticular formation and hypothalamus allow reflex control of cardiovascular, respiratory, and gastrointestinal functions.

Connections between the reticular formation and the dorsal motor vagus nuclei (via the reticulobulbar pathway) allow most of these reflexes to be mediated by the visceral motor component of CN X.