Vagus Nerve

About the Vagus Nerve

The vagus nerve is the tenth cranial nerve and the longest, its name coming from the Latin word for wandering. It leaves the medulla oblongata, exits the skull through the jugular foramen, and travels down the neck within the carotid sheath before branching to the larynx, heart, lungs, and much of the digestive tract. It carries most of the parasympathetic output of the body, slowing the heart rate and stimulating digestion, and most of its fibers are actually sensory, relaying information about the state of the internal organs back to the brain. Its branches also control the muscles of the larynx and pharynx, so damage, for example to the recurrent laryngeal nerve during neck surgery, can cause hoarseness. Overactivation of the vagal reflex is a common cause of fainting, known as vasovagal syncope. Implanted vagus nerve stimulators are approved for some people with drug resistant epilepsy and treatment resistant depression.