Vagus nerve
| Vagus nerve | |
|---|---|
Plan of the upper portions of the glossopharyngeal, vagus, and accessory nerves. | |
Course and distribution of the glossopharyngeal, vagus, and accessory nerves. | |
| Details | |
| Innervates | Levator veli palatini, salpingopharyngeus, palatoglossus, palatopharyngeus, superior pharyngeal constrictor, middle pharyngeal constrictor, inferior pharyngeal constrictor, viscera |
| Identifiers | |
| Latin | nervus vagus |
| MeSH | D014630 |
| NeuroNames | 702 |
| TA98 | A14.2.01.153 |
| TA2 | 6332 |
| FMA | 5731 |
| Anatomical terms of neuroanatomy | |
| Cranial nerves |
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The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibers and serves as a major pathway that connects the brain to various organs, including the heart, lungs, and digestive tract. As a key part of the parasympathetic nervous system, the vagus nerve helps regulate essential involuntary functions like heart rate, breathing, and digestion. By controlling these processes, the vagus nerve contributes to the body's "rest and digest" response, helping to calm the body after stress, lower heart rate, improve digestion, and maintain homeostasis.
There are two separate vagus nerves: the right vagus and the left vagus. In the neck, the right vagus nerve contains on average approximately 105,000 fibers, while the left vagus nerve has about 87,000 fibers, according to one source. Other sources report different figures, with around 25,000 fibers in the right vagus nerve and 23,000 fibers in the left.[1][2]
The vagus nerve is the longest nerve of the autonomic nervous system in the human body, consisting of both sensory - the majority - and some motor fibers, both sympathetic and parasympathetic. The sensory fibers originate from the jugular and nodose ganglia, while the motor fibers are derived from neurons in the dorsal nucleus of the vagus and the nucleus ambiguus.[3] Although historically the vagus nerve was also known as the pneumogastric nerve, reflecting its role in regulating both the lungs and digestive system, its role in regulating cardiac function is fundamental.
- ^ Hoffman, Henry Harland; Schnitzlein, Harold Norman (March 1961). "The numbers of nerve fibers in the vagus nerve of man". The Anatomical Record. 139 (3): 429–435. doi:10.1002/ar.1091390312. ISSN 0003-276X. PMID 13963923.
- ^ Neuhuber, Winfried L.; Berthoud, Hans-Rudolf (1 October 2022). "Functional anatomy of the vagus system: How does the polyvagal theory comply?". Biological Psychology. 174: 108425. doi:10.1016/j.biopsycho.2022.108425. ISSN 0301-0511. PMID 36100134.
{{cite journal}}: CS1 maint: article number as page number (link) - ^ Walker HK (1990). "Cranial Nerve XI: The Spinal Accessory Nerve". Clinical Methods: The History, Physical, and Laboratory Examinations (3rd ed.). Butterworths. ISBN 9780409900774. PMID 21250228. Retrieved 30 May 2019 – via NCBI Bookshelf.