Page 70 - Edited - Webster HEAD AND NECK - part 2-Merge PDF

HN 262 (PART 3)

A NOTE ON MUSCLE INNERVATIONS

The following refers in all cases to skeletal muscles.

TONGUE All muscles (including geniohyoid) are supplied by CrNXII
(hypoglossal) EXCEPT palatoglossus m. (CrNIX- glossopharyngeal).
HYPOGLOSSAL N. IS THE ONE TO REMEMBER.

SOFT PALATE All supplied by Vagus (CrNX) EXCEPT tensor palati (tensor veli
palatini) which is innervated by V3.
THE VAGUS N. IS THE ONE TO REMEMBER

PHARYNX ALL supplied by pharyngeal nerve plexus derived from CrN'sXI
(glossopharyngeal) and X (vagus). This applies to the three
constrictors and the three longitudinal muscles (stylopharyngeus,
salpingopharyngeus, palatopharyngeus). Stylohyoid is an ODDBALL
- CrN VII (facial).
PHARYNGEAL PLEXUS/CrN's IX and X ARE TO BE
REMEMBERED.

LARYNX All supplied by vagus (CrNX).
REMEMBER: CrNX, RECURRENT LARYNGEAL, SUPERIOR
LARYNGEAL NERVES.

MASTICATION 1.Primary (jaw movers, also speech) - CrNV3 (MANDIBULAR
TRIGEMINAL). Includes mylohyoid.
2. Secondary-buccinator - CrNVII (FACIAL).
tongue-CrNXII HYPOGLOSSAL.

SPEAKING 1. Primary jaw movers - CrNV3 (mandibular trigeminal n.).
2. Tongue-CrNXII (hypoglossal n.)
3. Lips - CrNVII (facial n.)
4. Soft palate - CrNX (vagus n.)
5. Larynx and pharynx - CrNX (vagus n.)
See later handout.

FACIAL EXPRESSION CrNVII, THE FACIAL NERVE. Also important is articulation of
speech (orbicularis oris) and mastication (buccinator), and hearing
(stapedius).

EXTRAOCULAR MUSCLES CrN's III, IV, VI (OCULOMOTOR, TROCHLEAR AND
ABDUCENT). All movements except abduction (lateral rotation)
depend on CrNIII, which also supplies levator palpebrae superioris
(skeletal muscle component). Remember also orbicularis oculi
(closure of lids e.g. blink reflex) - which is innervated by CrNVII
(facial).

K.E.W.

muscinner