Figure 1: Major vagal afferent innervation. The majority of the vagus nerve is comprised of sensory fibers and the cell bodies of vagal afferents are contained within the co-joined jugular and nodose ganglia. The afferent vagus innervates from the oral cavity to the transverse colon in humans, but tracing studies in rodent models have demonstrated afferent projections as caudal as the rectum, bladder, and reproductive tract. Vagal afferents carry mechanical and/or chemical sensory information to the caudal medulla, specifically the NTS and nucleus ambiguus. The cell bodies of the gastrointestinal viscera are distributed throughout the nodose ganglia (depicted in red) and vagally-mediated reflexes dominate esophageal and gastric reflexes. Functional alterations within all visceral organs following pathophysiological remodeling may become more pronounced in some disease and injury states. GI: Gastrointes tinal; NTS: nucleus tractus solitarius.