Vagus nerve



The vagus nerve, also called the tenth cranial nerve, starts in the brain and runs down the trunk of the body, with branches innervating the major organs. It interfaces with the parasympathetic nervous system and helps to regulate the heart, lungs, and the digestive system. It's a bi-directional nerve, meaning it both sends signals from the brain to the organs and the organs send messages back to the brain.

Function
The vagus nerve is an important sensor and regulator of basic functions including breathing, heart rate, the relaxation response, the gut-brain connection, and the formation of memories.

Immune system
The vagus nerve speaks directly to the immune system via the neurotransmitter acetylcholine.

When the vague nerve detects pro-inflammatory cytokines or tumor necrosis factor, it turns on the acetylcholine anti-inflammatory pathway. It is thus important for maintaining homeostasis and preventing an overreactive immune response that can cause major injury or death.

Learn more

 * Dr. Diana Driscoll: Vagus Nerve and POTS/Mast Cell Activation, The Low Histamine Chef, January 12 2016
 * 9 Nervy Facts About the Vague Nerve, Mental Floss