III) COURSE AND RELATIONS:Intracranial course Fibers of nerve pass forwards and laterally between the Olivary nucleus and the inferior cerebellar peduncle through the reticular formation of the medulla.
At the base of brain Nerve is attached by 3 to 4 filaments to the upper part of the posterolateral sulcus of the medulla, just above the rootlets of the vagus nerve.
Leaves the skull Filaments unite to form a single trunk and leave the skull by passing through the middle part of the jugular foramen anterior to the X th and XI th cranial nerves. It has a separate sheath of duramater.
Extracranial course Emerging at the base of the skull the nerve passes forwards and laterally between the internal jugular vein (which is posterolateral to it) and Internal carotid Artery (which is anterolateral to it). It then passes deep to styloid process and muscles attached to it. Winds around stylopharyngeus & passes between external and internal carotid arteries and reaches the side of pharynx. It enters the submandibular region by passing deep to the hypoglossus, where it breaks up into tonsillar and lingual branches.
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