General visceral afferent fiber

General visceral afferent fibers
Scheme showing pathways of a typical spinal nerve.
1. Somatic efferent.
2. Somatic afferent.
3,4,5. Sympathetic efferent.
6,7. Autonomic nervous system (ANS) afferent.
This image merely depicts pathways in a schematic fashion – it is not anatomically correct. The efferent sympathetics exit in a loop.
Anatomical terminology

The general visceral afferent (GVA) fibers conduct sensory impulses (usually pain or reflex sensations) from the internal organs, glands, and blood vessels to the central nervous system.[1] They are considered to be part of the visceral nervous system, which is closely related to the autonomic nervous system, but 'visceral nervous system' and 'autonomic nervous system' are not direct synonyms and care should be taken when using these terms. Unlike the efferent fibers of the autonomic nervous system, the afferent fibers are not classified as either sympathetic or parasympathetic.[2]

GVA fibers create referred pain by activating general somatic afferent fibers where the two meet in the posterior grey column.

The cranial nerves that contain GVA fibers include the glossopharyngeal nerve (CN IX) and the vagus nerve (CN X).[3]

Generally, they are insensitive to cutting, crushing or burning; however, excessive tension in smooth muscle and some pathological conditions produce visceral pain (referred pain).[4]

  1. ^ Moore, Keith; Anne Agur (2007). Essential Clinical Anatomy, Third Edition. Lippincott Williams & Wilkins. p. 635. ISBN 978-0-7817-6274-8.
  2. ^ Moore, Keith; Anne Agur (2007). Essential Clinical Anatomy, Third Edition. Lippincott Williams & Wilkins. pp. 34–35. ISBN 978-0-7817-6274-8.
  3. ^ Mehta, Samir et al. Step-Up: A High-Yield, Systems-Based Review for the USMLE Step 1. Baltimore, MD: LWW, 2003.
  4. ^ Susan, Standring (2016). Gray's anatomy : the anatomical basis of clinical practice. ISBN 9780702052309. OCLC 920806541.