Head & neck · Nerve
Vagus Nerve
The vagus nerve is a long cranial nerve that connects the brain to the heart, lungs and gut. It runs much of the body's "rest and digest" system, slowing the heart and aiding digestion.
What it is
The vagus nerve is the longest of the cranial nerves, wandering from the brainstem down through the neck and chest into the abdomen.
Where it runs
From the brainstem, down each side of the neck, into the chest and abdomen.
What it does
Carries signals of the parasympathetic ("rest and digest") system — slowing the heart, controlling the voice box, and driving digestion — and relays information back from the organs to the brain.
When things go wrong
Common problems affecting the vagus nerve
- Fainting (vasovagal syncope) from vagus over-activity
- Voice or swallowing problems if damaged
- Studied in vagus nerve stimulation therapies
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. New weakness or numbness, facial drooping, or loss of bladder or bowel control can be an emergency — call 999.
Did you know?
An interesting fact
The vagus nerve is central to the "rest and digest" state, and a sudden surge in its activity is what causes some people to faint at the sight of blood.
Answers
Vagus Nerve: frequently asked questions
What does the vagus nerve do?
It connects the brain to the heart, lungs and digestive system, slowing the heart and driving digestion as part of the "rest and digest" nervous system.
Why do some people faint at the sight of blood?
A sudden surge in vagus nerve activity can briefly slow the heart and drop blood pressure, reducing blood flow to the brain and causing a faint (vasovagal syncope).
Related nerves
Explore head & neck nerves
Sources
Where this is drawn from
- NHS — Nervous system
- Gray's Anatomy for Students
- TeachMeAnatomy — nervous system
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