Vagus nerve

The vagus nerve (X) is a mixed cranial nerve with predominantly sensory fibers. It carries visceral sensory information from the pharynx, larynx, trachea, esophagus, and thoracic and abdominal viscera, and also contains motor and parasympathetic fibers involved in the control of the pharynx, larynx, esophagus, heart, and digestive tract.

Number : X

Sensory, motor, or both : both, predominantly sensory

Origin : the nerve arises from the medulla oblongata by multiple small rootlets. Its somatic motor fibers originate from the nucleus ambiguus, while its preganglionic parasympathetic fibers originate from the parasympathetic nucleus of the vagus.

Route / Reports : the vagus nerve emerges from the lateral surface of the medulla and leaves the cranial cavity through the jugular foramen and tympanooccipital fissure together with the glossopharyngeal and accessory nerves. Caudal to its distal ganglion, it joins the sympathetic trunk to form the vagosympathetic trunk in the neck, then separates from it at the thoracic inlet and continues through the thorax toward the esophagus and abdominal viscera.

Distribution : sensory fibers supply the pharynx, larynx, trachea, esophagus, thoracic and abdominal viscera, and part of the external ear canal. Motor fibers supply striated muscles of the pharynx, larynx, and esophagus. Parasympathetic fibers innervate cardiac muscle, smooth muscle, and glands of the digestive tract as far caudally as the left colic flexure.

Description : The vagus nerve originates from the lateral medulla oblongata and exits the skull through the jugular foramen and tympanooccipital fissure. It then courses caudally through the neck as part of the vagosympathetic trunk, continues into the thorax, and distributes branches to the pharynx, larynx, heart, trachea, esophagus, and abdominal digestive organs.