Considering that those two cranial nerves are in detail linked, they’re described right here collectively. The glossopharyngeal cranial nerve acronym has a sensory and motor thing. The motor fibers arise from the nucleus ambiguous located within the lateral part of the medulla. at the side of the vagus and accent nerves, they leave the cranium through the jugular foramen. They supply the stylopharyngeus muscle whose function is to elevate the pharynx. Autonomic efferent fibers of the glossopharyngeal nerve rise up from the inferior salivatory nucleus. The preganglionic fibers bypass to the otic ganglion via the lesser superficial petrosal nerve. and postganglionic fibers bypass via the auriculotemporal branch of the 5th nerve to attain to reach the Parotid gland. The nuclei of the sensory fibers of the glossopharyngeal nerve are located inside the petrous ganglion which lies in the petrous bone below the jugular foramen and additionally the advanced ganglion, that is small. The exteroceptive fibers deliver the faucial tonsils, posterior wall of the pharynx, a part of the smooth palate and taste sensations from the posterior 1/3 of the tongue.
Vagus Cranial Nerve Disorders
The vagus: that is the longest amongst all the cranial nerves. The motor fibers arise from the nucleu ambiguus and deliver all the muscle mass of the pharynx, smooth palate and larynx, excluding tensor veli palati and stylopharyngeus. The parasympathetic fibers arise from the dorsal efferent nucleus and leave the medulla as preganglionic fibers of the craniosacral part of the autonomic anxious gadget. these fibers terminate on ganglia close to the viscera which they deliver through post-ganglionic fibers. The are parasympatahetic in characteristic. as a result vagal stimulation produces bradycardia, bronchial constriction, secretion of gastric and pancreatic juice and improved peristalsis. The sensory portion of the vagus has its nuclei inside the jugular in ganglion and ganglion nodosum. The vagus carries sensations from the posterior thing of the outside auditory meatus and adjoining pinna and pain sensation from the duramater lining the posterior cranial fossa.
trying out: it’s far higher to check the 9th and tenth nerve capabilities together as they’re affected typically together. Inquire for signs and symptoms like dysphagia, dysarthria, nasal regurgitation of fluids and hoarseness of voice. The motor part is examined by means of analyzing the uvula whilst the affected person is made to open his mouth. The Uvula is generally inside the midline. In unilateral vagal paralysis, the palatal arch is flattened and lowered ipsilaterally. On phonation, the uvula is deviated to the everyday aspect.
The gag reflex or the pharyngeal reflex is elicited by means of applying a stimulus, together with a tongue balde or cotton to the psoterior pharyngeal wall or tonsillar location. If the reflex is gift, there might be elevation and contraction of the pharyngeal musculature observed by retraction of the tongue. The afferent arch of this reflex is subserved by way of the glossopharyngeal at the same time as the efferent is thru the vagus. This reflex is lost in either 9th or tenth nerve lesions. check for widespread sensations over the posterior pharyngeal wall, tender palate and faucial tonsils, and flavor over the posterior third of the tongue. those are impaired in glossopharyngeal paralysis.
problems of ninth and 10th nerve functions
isolated involvement of either nerve is uncommon and usually they’re worried collectively, frequently the eleventh and 12th nerves can also be affected. Glossopharyngeal neuralgia resembles trigeminal neuralgia, however it’s miles a lot less not unusual. It happens as paroxysmal extreme ache originating in the throat from the tonsillar fossa. it is able to be related to bradycardia and in such cases it’s far called vegoglossopharyngeal neuralgia. an ordeal of phenytoin or carbamazepine is usually powerful in relieving ache. mind stem lesions like motor neuron disease, vascular lesions which includes lateral medullary infarction or bulbar poliomyelitis can have an effect on these nerves collectively ensuing in bulbar palsy. Posterior fossa tumors and basal meningitis may additionally contain these nerves outdoor the mind stem. complete bilateral vagal paralysis is incompatible with life. Involvement of the recurrent laryngeal nerves, in particular the left, happens in thoracic lesions and this produces simplest hoarseness of voice without dysphagia.