There are two subdivisions of the superior laryngeal nerve.

The superior laryngeal nerve is a branch of the vagus nerve.

A superior laryngeal nerve palsy changes the pitch of the voice and causes an inability to make explosive sounds.

To its medial side are the Constrictor pharyngis inferior and the external branch of the superior laryngeal nerve.

Sensory innervation to the glottis and laryngeal vestibule is by the internal branch of the superior laryngeal nerve.

Medial to it are the hyoid bone, the wall of the pharynx, the superior laryngeal nerve, and a portion of the parotid gland.

In fact, it has been shown that the swallowing reflex can be initiated entirely by peripheral stimulation of the internal branch of the superior laryngeal nerve.

The superior laryngeal artery accompanies the internal laryngeal branch of the superior laryngeal nerve, beneath the Thyreohyoideus.

The gland is supplied by parasympathetic nerve input from the superior laryngeal nerve and the recurrent laryngeal nerve.

Instead, they are innervated by the recurrent laryngeal nerve and the external branch of the superior laryngeal nerve, branches of the vagus.

This reflex may also be impaired by damage to the internal branch of the superior laryngeal nerve which relays the afferent branch of the reflex arc.

Marchese-Ragona R,et al.: The superior laryngeal nerve injury of a famous soprano, Amelita Galli-Curci.

A nerve to her larynx, the external branch of the superior laryngeal nerve, is thought to have been damaged, resulting in the loss of her ability to sing high pitches.

Deep to the mucous membrane of the piriform fossa lie the recurrent laryngeal nerve as well as the internal laryngeal nerve, a branch of the superior laryngeal nerve.

Divide the superior thyroid artery and vein close to the thyroid gland (avoid injury to the external branch of the superior laryngeal nerve and the superior parathyroid gland)

When triggered, impulses travel via the internal laryngeal nerve, a branch of the superior laryngeal nerve which stems from the vagus nerve (CN X), to the medulla of the brain.

This muscle is the only laryngeal muscle supplied by the branch of the vagus nerve known as the external branch of the superior laryngeal nerve (rather than the recurrent laryngeal nerve).

The nerve splits into anterior and posterior rami before supplying muscles in the voice box - it supplies all laryngeal muscles except for the cricothyroid, which is innervated by the external branch of the superior laryngeal nerve.

The efferent neural pathway then follows, with relevant signals transmitted back from the cerebral cortex and medulla via the vagus and superior laryngeal nerves to the glottis, external intercostals, diaphragm, and other major inspiratory and expiratory muscles.

Its middle thicker part is termed the middle hyothyroid ligament (ligamentum hyothyreoideum medium; middle thyrohyoid ligament), its lateral thinner portions are pierced by the superior laryngeal vessels and the internal branch of the superior laryngeal nerve.

Other than the cricothyroid muscle which is innervated by the superior laryngeal nerve, motor control of all the intrinsic muscles of the larynx, the thyroarytenoid, the posterior and lateral cricoarytenoid, and arytenoid muscles depends upon the recurrent laryngeal nerve.

Posterior to it, near its origin, is the superior laryngeal nerve; and higher up, it is separated from the internal carotid by the Styloglossus and Stylopharyngeus, the glossopharyngeal nerve, the pharyngeal branch of the vagus, and part of the parotid gland.

It is also worth noting that all muscles are innervated by the recurrent laryngeal branch of the vagus except the cricothyroid muscle, which is innervated by the external laryngeal branch of the superior laryngeal nerve (a branch of the vagus).