Visceral Afferents
« Back to Glossary IndexVisceral afferents are sensory neurons stimulated by changes in body organs (heart, lungs, GI tract), membranes, and attachments to body wall and communicate them to the central nervous system (brain and spinal cord). Part of the visceral nervous system in the autonomic nervous system (ANS), afferent signals help monitor/regulate the physiology of organs and augment conscious perception of pain, organ filling, nausea, bloating/ distension, and dyspnea (shortness of breath). Also see General Senses, Somatic Afferents, and Afferents. Two types of visceral afferent fibers, plus a third category that specifically related to the ANC:
- General visceral afferents (GVA) carry sensory information from most internal organs, including sensations like stretching, pressure changes, and stomach/intestines/bladder pain.
- Special visceral afferents (SVA) carry sensory information related to taste (tongue) and smell (olfactory epithelium). The glossopharyngeal nerve (tongue, throat, middle ear, parts of head/neck) contains SVA fibers for taste from the back of the tongue.
- Vagus nerve carries both GVA fibers from the thoracic and abdominal viscera and a small amount of SVA fibers from the epiglottis.
- Sympathetic visceral afferents are linked to the fight-or-flight response (FFR) and are responsible for carrying pain signals from the viscera, like organ distension or inflammation.
- Parasympathetic visceral afferents convey information, mainly via the vagus nerve, linked to “rest and digest,” like stomach fullness or blood pressure changes—and modulate pain signals
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