The most severely affected muscles include facial muscles and the tongue (which may develop a twitch due to hypoglossal nerve paralysis).
This so-called nucleus raphes obscurus has also been implicated in the modulation of the hypoglossal nerve.
There is anastomosis with accessory nerve, hypoglossal nerve and sympathetic trunk.
This nucleus has been known to innervate the caudal hypoglossal nucleus, and responds to glutamateric stimuli.
Their axons project down to the bulbar/spinal motor systems, such as the hypoglossal nucleus which harbors the motor neurons of the tongue muscles.
Sometimes the descending branch of the hypoglossal nerve is contained within the sheath.
The lower sternocleidomastoid branch passes inferio-external to the hypoglossal nerve before descending into the substance of the muscle to which its name is derived.
At the base of the skull the glossopharyngeal, vagus, accessory, and hypoglossal nerves lie between the artery and the internal jugular vein.
