[The skin and mucosa of the head and neck area...What was the innervation again?].

The skin innervation of the head and neck area is largely provided by the trigeminal nerve and the cervical plexus. The separation between the two areas is approximately on the line crown-jaw-chin. The face is provided by the trigeminal nerve (nervus V), while the area below it up to the shoulders is provided by the cervical plexus. The innervation from the oral mucosa to the esophagus is provided by the trigeminal nerve, glossopharyngeus and vagus. This segmental distribution allows for a clear organization of the sensory input, which is clinically important in diagnosing disorders.