Solitary tract

The solitary tract (Latin: tractus solitarius) is a compact fiber bundle that extends longitudinally through the posterolateral region of the medulla. The solitary tract is surrounded by the nucleus of the solitary tract, and descends to the upper cervical segments of the spinal cord.

Composition

The solitary tract is made up of primary sensory fibers and descending fibers of the vagus, glossopharyngeal, and facial nerves.

Function

The solitary tract conveys afferent information from stretch receptors and chemoreceptors in the walls of the cardiovascular, respiratory, and intestinal tracts. Afferent fibers from cranial nerves 7, 9 and 10 convey taste (SVA) in its rostral portion, and general visceral sense (GVA) in its caudal part. Taste buds in the mucosa of the tongue can also generate impulses in the rostral regions of the solitary tract. The efferent fibers are distributed to the solitary tract nucleus.

Synonyms

There are numerous synonyms for the solitary tract:

• round fasciculus (Latin: fasciculus rotundus)
• solitary fasciculus (Latin: fasciculus solitarius)
• solitary bundle (Latin: funiculus solitarius)
• Gierke respiratory bundle
• Krause respiratory bundle

See also

• Solitary nucleus

References

• Stedman, Thomas Lathrop (2006). Stedman's Medical Dictionary, 28th edition. Baltimore, MD: Lippincott Williams & Wilkins. p. 2011. ISBN 0-7817-3390-1. http://www.emedicine.com/asp/dictionary.asp?keyword=solitary+tract.