Anatomy
CN X
Definition
The vagus nerve is the tenth cranial nerve and a major two-way communication pathway between the brainstem and organs in the chest and abdomen.
Aliases and abbreviations
CN X · cranial nerve X · tenth cranial nerve
Editorial record
Published: August 25, 2026 · Reviewed: August 25, 2026
Expanded definition
The vagus nerve contains sensory, motor, and parasympathetic fibres. It carries information from the body toward the brain and sends signals from the brainstem toward structures involved in functions such as heart rate, digestion, swallowing, and voice.
It is often discussed in relation to autonomic regulation because it supplies much of the parasympathetic output to organs below the neck. That does not make it a single “calm switch”; nervous-system states emerge from interacting brain, body, behavioural, and environmental processes.
Vagus nerve stimulation is a separate concept. It refers to deliberate stimulation intended to influence vagal pathways and includes implanted as well as non-invasive methods.
What the term does not establish
Why the distinction matters
Understanding the anatomy helps readers separate the nerve itself from broader ideas such as vagal tone, autonomic regulation, and the different methods grouped under VNS.
Main guide
A broader introduction to anatomy, communication pathways, stress, sleep, and recovery.
Read the vagus nerve guideRelated terms
Stimulation methods
Nervous system
Nervous system
Nervous system
Anatomy
Editorial scope
This glossary entry supports general education. It does not diagnose, recommend treatment, or transfer findings from one VNS method, protocol, or device to another.