The details of course and distribution of human internal
laryngeal nerve was studied in eleven dissected human larynges.
The internal laryngeal nerve is divided into three divisions:
superior, middle and inferior. The superior division supplies the
most posterior part of the •m ucosa of the tongue, vallecula,
lateral and median glossoepiglottic folds and the epiglottis
(lingual and laryngeal surfaces). The middle division supplies the
aryepiglottic fold and mucosa of the laryngeal vestibule. The
inferior division supplies the mucosa of piriform fossa, the
mucosa covering back of interarytenoid region, the mucosa -
covering the back of posterior lamina of cricoid cartilage and the
mucosa covering the sides of laryngopharynx. The inferior
division gives anastomotic branch to the recurrent laryngeal
nerve. It also appears to supply motor innervation to the
interarytenoid muscle and upper oesophageal sphincter. This
observation is contrary to current concepts of the internal
laryngeal nerve as a purely sensory nerve. These findings can be
used to guide surgical attempts to reinnervate the laryngeal
mucosa when the sensation is lost due to neurological disease
and can play a role in the explaination of different positions of
vocal cords in cases of vocal cord paralysis. |
