igen ; 
ceed aes ene 
-~ 
THE SEVENTH OR FACIAL NERVE. 645 
pars intermedia intervening. In the aqueduct of Fallopius the nerve first passes 
backwards on the inner side of the tympanum, and then downwards behind the 
tympanum, in the inner wall of the tympanic antrum. Jn the parotid gland 
the nerve crosses superficially the external 
carotid artery and the temporo-maxillary 
vein. On the face its branches radiate from 
the anterior border of the parotid gland and 
enter the deep surface of the facial muscles. 
Branches and Communications.—(1i.) J the 
internal auditory meatus the pars inter- 
media (n. interniedius), lying between the 
facial and auditory nerves, sends communti- 
eating branches to both. The branch to 
the auditory nerve probably separates from 
it again to join the geniculate ganglion of 
the facial nerve. 
(ii.) In the aqueduct of Fallopius the 
geniculate ganglion (2g. genicull) is formed at 
the point where the facial nerve bends back- 
wards (geniculum n. facialis). It is an oval 
swelling on the nerve, and is joined by a 
branch trom the upper (vestibular) trunk of 
the auditory nerve, by which it probably 
receives fibres of the pars intermedia. From 
the ganglion three small nerves arise :— Fic. 463.— THE FactaL NERVE WITH ITs 
(1) The large superficial petrosal nerve passes BRANCHES AND COMMUNICATIONS IN THE 
forwards through the hiatus Fallopii to the — S@UPPUCT OF Fatnorres. 
middle fossa of the base of the skull. On VIL Facial nerve ; P.1, Pars intermedia ; VII, 
the upper surface of the foramen lacerum ae Ba ete eA hho a 
medium it is joined by the great deep petrosal ternal superficial petrosal nerve ; M.M, Middle 
nerve from the sympathetic plexus on the eee aU eee ee eee 
. ea; et ee ey se “sa petrosal nerve: G.P.D, Great deep petrosa 
internal carotid artery to form the vidian nerve; I.C, Internal carotid artery; Vid, 
nerve, which, atter traversing the vidian Vidian nerve; M.G, Meckel’s ganglion; Ty.PI, 
canal, ends in Meckel’s ganglion. (2) A Tympanic plexus ; §8.D.P, Small deep petrosal 
Maen Geaey erees ane ar vara pone nerve ; G.Ph, Glosso-pharyngeal nerve; 'Ty, 
: 2 ne UNE!) Mais ee ES hs 2h: Ore: One Tympanic branch; §8.S.P, Small superficial 
and joins the tympanic branch of the glosso-__petrosal nerve; 0.G, Otic ganglion; Stap, 
pharyngeal in the substance of the bone. Nerve fo. ane: wee eee tympani 
y ae - : nerve; L, Lingual nerve; A.Va, Communication 
>y their Ce tos) the small superficial petrosal with auricular branch of vagus; P.A, Posterior 
nerve 15 formed, which pierces the temporal auricular nerve ; Sty.hy, Nerve to stylo-hyoid ; 
bone and ends in the otic ganglion. (3) Di, Nerve to digastric (posterior belly) ; T. F, 
he external superficial etrocal See ian Temporo-facial division ; C.F, Cervico - facial 
: : 2 Pp ceaow eta eee a division ; T, Temporal ; M, Malar; 1.0, Infra- 
minute ineconstant branch which jos the orbital ; B, Buccal ; 8.M, Supra-mandibular, 
sympathetic plexus on the middle meningeal nd 1M, Infra-mandibular branches. 
artery. 
In the course of the facial nerve in the lower part of the aqueduct of Fallopius, 
behind the tympanum, three branches arise—(1) The small nerve to the stapedius 
muscle, which passes forwards to the tympanum. (2) The chorda tympani nerve 
(probably associated with the pars intermedia), which enters the tympanic 
cavity through the iter chorde posterius, passes over the membrana tympani and 
the handle of the malleus, and leaves the cavity through the zter chordwe anterius 
to reach the pterygoid region. Beneath the external pterygoid muscle it becomes 
incorporated with the lingual branch of the inferior maxillary nerve, and in its 
further course is inseparable from that nerve. It supplies a root to the sub- 
maxillary ganglion, and is finally distributed (probably as the nerve of taste) to 
the side and dorsum of the tongue in its anterior two-thirds. The chorda tympani 
nerve receives beneath the external pterygoid muscle a fine communication from 
the otic ganglion. (3) Before it leaves the aqueduct of Fallopius a fine com- 
municating branch arises from the facial nerve to join the auricular branch of the 
pheumogastric nerve. 
“a ; , - 
