What Is the Superior Laryngeal Nerve?

Superior Laryngeal Nerve: The superior laryngeal nerve is a branch of the vagus nerve that is divided into internal and external branches at a height equivalent to the large angle of the hyoid bone. The outer branches are mainly motor nerves that innervate the ciliary thyroid muscles and the pharyngeal constrictor muscles, but there are also sensory branches that pass through the ciliary membrane to the vocal cords and the mucosa in the front of the subglottic area. The inner branch is mainly the sensory nerve. It penetrates the thyroid hyoid periosteum behind the superior laryngeal artery and is distributed above and below the epiglottis, epiglottis, glottis behind the glottis, oropharynx, a small part of the laryngo-pharynx, and the front of the spoon-shaped cartilage. Mucosa. Motor nerve fibers may also dominate the scab muscle. The inner branch has an anastomosis with the posterior branch of the recurrent laryngeal nerve. One of the branches of the vagus nerve in the superior laryngeal nervous system in the neck. It starts from the nodular ganglia and descends along the pharyngeal constrictor on the inner side of the internal carotid artery to the large corner of the hyoid bone. It is divided into two branches: the outer branch, which innervates the circumferenalis, and the inner branch, which penetrates the nail with the superior laryngeal artery. The hyoid periosteum enters the larynx and is divided into several small branches to the epithelium, tongue base, pear-shaped crypt, and mucosa above the glottis. If this nerve is damaged, the movement and sensation of its distribution area will be impaired.

Superior Laryngeal Nerve: The superior laryngeal nerve is a branch of the vagus nerve that is divided into internal and external branches at a height equivalent to the large angle of the hyoid bone. The outer branches are mainly motor nerves that innervate the ciliary thyroid muscles and the pharyngeal constrictor muscles, but there are also sensory branches that pass through the ciliary membrane to the vocal cords and the mucosa in the front of the subglottic area. The inner branch is mainly the sensory nerve. It penetrates the thyroid hyoid periosteum behind the superior laryngeal artery and is distributed above and below the epiglottis, epiglottis, glottis behind the glottis, oropharynx, a small part of the laryngo-pharynx, and the front of the spoon-shaped cartilage. Mucosa. Motor nerve fibers may also dominate the scab muscle. The inner branch has an anastomosis with the posterior branch of the recurrent laryngeal nerve. One of the branches of the vagus nerve in the superior laryngeal nervous system in the neck. It starts from the nodular ganglia and descends along the pharyngeal constrictor on the inner side of the internal carotid artery to the large corner of the hyoid bone. It is divided into two branches: the outer branch, which innervates the circumferenalis, and the inner branch, which penetrates the nail with the superior laryngeal artery. The hyoid periosteum enters the larynx and is divided into several small branches to the epithelium, tongue base, pear-shaped crypt, and mucosa above the glottis. If this nerve is damaged, the movement and sensation of its distribution area will be impaired.

Chinese name

Superior laryngeal nerve

Foreign name

superior laryngeal nerve

Overview of the superior laryngeal nerve

1. Sublaryngeal nerve: The recurrent laryngeal nerve penetrates into the peripheral branch of the larynx. This nerve enters the throat into two branches (there are many more); there are also branches that enter the throat before entering the throat. The position of the sublaryngeal nerve at the branch of the external larynx can be below the thyroid gland, it can also be below the middle thyroid gland, or above the middle thyroid gland. This situation is very important during surgery. The anterior branch of the inferior laryngeal nerve is distributed in the lateral iliac muscle, onychomycosis muscle, epicondyle muscle, vocal cord muscle and epithyroid muscle, transverse diaphragm, and oblique muscle. The sublaryngeal nerve emits thin branches of mucous membranes distributed on the caudal side of the vocal cord; in addition, the sublaryngeal nerve sends out branches to communicate with the inner branches of the superior laryngeal nerve.

2. Vagus nerve: The vagus nerve is a mixed nerve. Its motor fibers originate from the suspicious nucleus and run parallel to the glossopharyngeal nerve. After passing through the brain stem, it passes through the jugular foramen to the cranial cavity. It supplies all pharynx, larynx, Soft palate muscles. The sensory neurons are in the cervical ganglia and nodal ganglia near the jugular foramen. The peripheral branches of the cervical ganglia conduct part of the general sensations of the external auditory canal, tympanic membrane, and auricle; the central branch branches into the spinal nucleus of the brainstem of the trigeminal nerve. The peripheral branches of the nodal ganglion conduct the sensations of the pharynx, larynx, trachea, esophagus, and various internal organs, as well as the taste of the pharynx, soft palate, hard palate, and epiglottis; the central branch enters the arcuate nucleus. Parasympathetic nerves originate from the dorsal nucleus of the vagus nerve at the bottom of the fourth ventricle and are distributed to internal organs.

Superior laryngeal nerve anatomy

1. Superior laryngeal nerve: The superior laryngeal nerve originates from the inferior (nodular) ganglion of the vagus nerve, descends on the inner side of the internal carotid artery, and is divided into internal and external branches at the large angle of the hyoid bone. The outer branch innervates the ciliary thyroid muscle, and the thin branches are branched to the thyroid. The inner branch and the superior laryngeal artery pass through the thyroid hyoid bone into the larynx and are divided into many small branches, which are distributed in the laryngeal mucosa, epiglottis, and root of the tongue above the glottis.

2. Sublaryngeal nerve: it is the peripheral branch of the recurrent laryngeal nerve of the vagus nerve. The sublaryngeal nerve enters the larynx and is divided into anterior and posterior branches. The anterior branch is distributed in the lateral iliac muscle, onychomycosis muscle, vocal cord muscle, epicondyle muscle and onychomycosis muscle. The posterior branch is distributed in the posterior ring muscle, transverse diaphragm, and oblique muscle, and the thin branches are distributed in the mucosa of the vocal cord tail. In addition, there are branches that communicate with the inner branches of the superior laryngeal nerve.

3. Vagus nerve: It is a mixed nerve, which is the nerve with the longest stroke and the most widely distributed nerve in the brain nerve. The vagus nerve is connected to the glossopharyngeal nerve with 8 to 10 root filaments. From the back of the posterior lateral sulcus of the medullary medulla, between the dorsal aspect of the corpus callosum and the lower cerebellum, the brain passes through the jugular foramen and exits the cranial nerve. Swells and forms the upper and lower ganglia and enters the neck. In the neck, the vagus nerve descends behind the internal jugular vein, and between the internal jugular and common carotid arteries, and passes through the upper thoracic cavity into the thoracic cavity. In the chest, the left and right vagus nerves have different relationships with the surrounding structures during the stroke. The left vagus nerve passes between the left common carotid artery and the left subclavian artery, passes through the front of the aortic arch, passes through the back of the left lung root, and spreads into several thin branches in front of the esophagus, forming the anterior esophagus plexus, which continues to the anterior vagus trunk at the lower end of the esophagus. The right vagus nerve passes before the subclavian artery, descends along the right side of the trachea, passes behind the right lung root, and passes behind the esophagus to form a posterior esophagus plexus, which forms the posterior vagus trunk. The anterior and posterior stems of the vagus go down with the esophagus through the esophageal hiatus of the diaphragm into the abdominal cavity, and reach the anterior and posterior branches of the stomach.

Diseases related to the superior laryngeal nerve

1. Paralysis of the outer branch of the superior laryngeal nerve:

[Overview]

The outer branch of the superior laryngeal nerve is a motor nerve that innervates the ciliate thyroid muscle. The inner branch of the superior laryngeal nerve is a sensory nerve distributed in the upper mucosa of the laryngeal cavity. Paralysis can be compensated by the contralateral side without asymptoms, and the external branch injury is manifested as paralysis of the affected side of the nail.

[Clinical manifestations]

Weak vocal strength, thick tones, low pitches, air leaks, shortened vocal hours, fatigue, treble and singing. When the unilateral upper laryngeal nerve is paralyzed, the ring side of the healthy side can still contract when it is pronounced. The thyroid cartilage is twisted to the healthy side by 5 ° -10 °, and the half of the ring side of the cartilage is lifted up. The glottis is skewed, with the anterior joint toward the healthy side and the posterior joint toward the affected side. When the lateral superior laryngeal nerve is paralyzed, the glottis is not deflected, but the vocal cords are corrugated, incompletely closed, the pronunciation is deep and leaky, and the ring-shaped cartilage is shortened to shorten the distance between the ring nails. Due to bilateral paralysis of the inner branch, a significant diet may occur, and saliva is inhaled into the trachea by mistake. The laryngeal electromyogram showed abnormal changes. The X-ray examination showed no change in the distance between the ring nails. Bilateral superior laryngeal nerve palsy is rarely seen clinically ^[1] .

[Auxiliary inspection]

Laryngeal electromyography should be performed in a timely manner, and X-ray examination can help to understand the specific situation of the disease.

diagnosis

(1) Weak vocal strength, thick tones, low pitches, air leaks, shortened vocal hours, fatigue, difficulty in tweeting and singing.

(2) When unilateral upper laryngeal nerve is paralyzed, the glottis is deflected during indirect laryngoscopy, the anterior joint is biased to the healthy side, and the posterior joint is biased to the affected side. When the bilateral upper laryngeal nerve is paralyzed, the glottis is not deflected, but the vocal cords are corrugated, incompletely closed, and the pronunciation is low and leaking. The symptoms and signs can temporarily disappear.

(3) There were abnormal changes in the laryngeal electromyogram examination, and there was no change in the distance between the ring nails when the X-ray examination made treble.

treatment

Etiology treatment, pronunciation training, most patients can compensate. If it is not effective, it can be treated surgically, such as replacing the thyroid gland muscle with the thyrohyoid muscle.

2. Upper laryngeal nerve block: The upper laryngeal nerve block is often used when intubating an awake patient. This technique is also used during oral endoscopy, transesophageal echocardiography, and other instrumental examinations of the larynx and esophagus. Place the needle between the thyroid cartilage and the hyoid bone, 1 to 5 cm in front of the large horn of the thyroid cartilage. Through the thyroglossal periosteum, anesthetic is injected around the larger terminal branch of the superior laryngeal nerve, that is, the inner laryngeal nerve. The laryngeal mucosa above the vocal fold and the upper surface of the vocal ridge are anesthetized.