![]() ![]() Sympathetic fibers are supplied from the superior cervical ganglion via branches from the plexus on the external carotid artery this element is vasoconstrictor 4. The vagal contribution to the pharyngeal plexus supplies the muscles of the pharynx except (stylopharyngeus) and the muscles of the soft palate (except tensor veli palatini) 4. Although, recently, discussion regarding the accessory nerve’s contribution has arisen on the basis of connections between the accessory nerve and vagus nerve in the posterior fossa being variable 5. Motor fibers of the pharyngeal branch of the vagus originating from the cranial part of the accessory nerve are described as acting as the major motor drive to the pharyngeal plexus 3,9,10. It contains motor fibers originating from the nucleus ambiguus in the medulla as well as afferents originating in the sensory nucleus of the trigeminal nerve 4,6. ![]() The pharyngeal branch of the vagus emerges from the upper part of the inferior vagal ganglion and passes forward between the internal and external carotid arteries parallel with and below the glossopharyngeal nerve to join the pharyngeal plexus at the upper border of the middle pharyngeal constrictor muscle 1,2,4. Parasympathetic fibers from the inferior salivary nucleus are also supplied to the mucous and serous glands of the oropharynx via the pharyngeal branches of the glossopharyngeal nerve 4. This component is afferent and supplies the mucous membrane of the oropharynx with common sensation and some taste fibers 3,4. It joins the pharyngeal branch of the vagus nerve which proceeds to join the pharyngeal plexus and pierce the middle constrictor muscle 3,4. The pharyngeal branch of the glossopharyngeal nerve arises prior to the glossopharyngeal nerve curving around the posterior border and lateral side of the stylopharyngeus 3,6. It is formed by the pharyngeal branches from the vagus and glossopharyngeal nerves and the cervical sympathetic 3-7. The pharyngeal plexus sends some branches between the middle and inferior constrictors and other branches between the superior and middle constrictors 4,6. It lies mainly over the middle pharyngeal constrictor muscle 4,5 although it spreads its branches over the dorsolateral surface of the both the superior and middle constrictors, and lower branches descend onto the inferior constrictor 6. The pharyngeal plexus lies within the external fascia of the pharynx 3 on the posterolateral wall of the pharynx in the retropharyngeal space 7. Relations: the pharyngeal plexus lies in the retropharyngeal space between the superior and middle constrictor muscles anteriorly and the longus capitus and colli muscles, prevertebral fascia, and bodies of the second and third cervical vertebrae posteriorly 7 and medial to the buccopharyngeal fascia 8 Supplies the superior, middle and inferior pharyngeal constrictor muscles, palatopharyngeus, salpingopharyngeus, levator veli palatini, palatoglossus and the muscle of the uvula 4,5 Origin and course: it is formed from the union of branches from the vagus nerve, glossopharyngeal nerve and cervical sympathetic nerves 4,5įilaments from the plexus ascend or descend external to the superior and inferior constrictors 5 before branching within the muscular layer and mucosa of the pharynx 4,5 Location: within the external fascia of the pharynx 3, mainly over the middle pharyngeal constrictor on the posterolateral wall of the pharynx 4
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