Special visceral afferent

Special visceral afferent (SVA) refers to afferent nerves that develop in association with the gastrointestinal tract. They carry the special senses of smell (olfaction) and taste (gustation). The cranial nerves containing SVA fibers are the olfactory nerve (I), the facial nerve (VII), the glossopharyngeal nerve (IX), trigeminal nerve (V) and the vagus nerve (X). The facial nerve receives taste from the anterior two-thirds of the tongue; the glossopharyngeal from the posterior third. SVA fibers in the vagus originate in the epiglottis and pharynx. The sensory processes, using their primary cell bodies from the inferior ganglion, send projections to the medulla, from which they travel in the tractus solitarius, later terminating at the rostral nucleus solitarius.