Cranial nerves VII; 7

Nervus facialis

Facial nerve, Seventh cranial nerve, Nervus intermedius

Comes out on the side of the extended pith just below the pier. The nerve disappears into the temporal bone where it travels through a long, narrow and tortuous canal before reaching the outside of the skull.
On its way, inside the brainstem, from the motor facial nerve nucleus and before discharge from the brainstem, the facial nerve fibers round the core of the sixth cranial nerve (n.abducens) and form the so-called inner knee of the facial nerve.

The facialis nerve has two roots where it emerges from the brain stem:

1/ a major motor root that starts from the motor facial nucleus and

2/ a smaller "sensory" root that leads in taste threads to the solitarius nucleus and leads out parasympathetic filaments from the nucleus salivatorius superior. The sensory root was previously called the "nervus intermedius".

The nerve supplies the motor muscles of the face (the mimic muscles, which include the cheek/trumpeter muscle, the muscles of the mouth-nose openings, the blink muscle, the laughing muscle, etc.).

Parasympathetic nerve fibers affect saliva formation and the production of tear fluid.

The facial nerve also conveys taste from the front of the tongue and has a small sensory ganglion inside the bone canal.