The vagus presents a well-marked ganglionic enlargement, which is called the superior ganglion of the vagus nerve. It contains afferent somatosensory neuronal cell bodies that provide sensory information from the external auditory meatus (auricular branch), cranial meninges (meningeal branch), and the external surface of the tympanic membrane. Their central fibers synapse in the sensory trigeminal nucleus.

It is of a grayish color, spherical in form, and about 4 mm. in diameter.