VAN 121: Veterinary Gross Anatomy-II (2+2)

GLOSSO PHARYNGEAL NERVE

• This is a mixed nerve. It is attached to the lateral part of the medulla at its anterior aspect by several filaments ventral to the restiform body and are separated by a narrow interval from the preceding nerve in front and the vagus behind.
• The nerve fibres converge laterally into a bundle that pierces the dura, emerges through the foramen lacerum and then bears a ganglion called petrosal ganglion. It then curves forward and downward, behind the great cornu of the hyoid divided into the pharyngeal and the lingual branches. Its branches are
• The tympanic nerve arises from the petrosal ganglion passes upward between the petrous and tympanic parts of the temporal bone to reach the cavity of tympanum. Here it forms along with branches from the plexus of the sympathetic, the tympanic plexus. From the plexus, branches pass to the mucous membrane of the tympanum and pharyngotympanic tube. The continuation of the nerve from the plexus joins a branch from the geniculate ganglion. The lesser superficial petrosal nerve conveys parasympathetic fibres supplying the parotid salivary gland, after relay in the otic ganglion.
• a small branch to supply stylopharyngeus muscle.
• Pharyngeal branch with which branches of vagus and sympathetic forms the pharyngeal plexus and supplies the mucous membrane of the pharynx.
• The lingual branch supplies gustatory and ordinary sensory fibres to the posterior one third of the tongue. It also supplies soft palate, tonsil and isthmus faucium.