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THE NERVOUS SYSTEM. 307
The Branch of Communication with the Tympanic Plexus is a small
nerve which connects the geniculate ganglion with the sympathetic tym-
panic plexus.
Tlie Communicating Branch with the Pneumogastric Nerve passes out
of the stylo-mastoid foramen, and communicates with the pneumogastric
nerve through its articular branch.
The Commumcating Branch with the Glosso-pharyngeal Neri^e arises
from the facial as it leaves the stylo-mastoid foramen. It communicates
with the glosso-pharyngeal nerve below its petrosal ganglion.
The branches of the facial nerve before it escapes from the stylo-
mastoid foramen are
1 Stapedius
2. Chorda tympani
3. Connecting branches with pneumogastric nerve
;
4. Connecting branches M'ith glosso-pharyngeal nerve.
The Stapedius or Tympanic Nerve is the most slender branch given
off by the facial nerve. It arises opposite the pyramid of the internal
ear, passes through a fine canal, and is distributed to the stapedius nmscle.
Tlte Chorda Tympani Nerve arises from the facial nerve on the proxi-
mal side of the geniculate ganglion, though apparently it arises back of
the tympanum close to the outer extremity of the aqueduct of Fal-
lopius. From its origin it passes upward in a special curved canal
nearly parallel to the aqueduct of Fallopius, and enters the posterior
wall of the tympanic cavity close to the tympanic membrane. It here
becomes invested by mucous membrane, arches upward between the
long handle of the malleus and the vertical process of the incus to its
anterior angle. It then passes out of the tympanum through a for-
amen (canal of Hugui) at tlie side of the glenoid (Glasserian) fissure,
extends downward on the proximal side of the internal lateral ligament
of the inferior maxillary bone, and forms a union with the lingual
branch of the fifth nerve at a point where the nerve forms an acute
angle by bending forward under the inferior border of the external
pterygoid muscle. It is then distributed to the submaxillary muco-
salivary gland and to the tongue. The chorda tympani nerve receives
a communicating branch from the otic ganglion just before joining the
lingual nerve. There is considerable discussion among anatomists and
physiologists as to the origin and functions of this nerve. Some claim
that it is a continuation of the nerve of Wrisberg, while J. Sapolini
claims it as an independent cranial nerve, entitled to be classed as
the thirteenth cranial nerve. Its function is also still in doubt, some
claiming it to be a motor nerve, others a nerve of sensation, while
others regard it as a special nerve of taste.
The Communicating Brcmch with the Pneumogastric Nerve arises from
the facial nerve a little before its exit from its canal to join the upper
ganglion of the pneumogastric. This branch is not constant.
The Communicating Brcmch with the Glosso-pharyngeal Nerve arises
from the facial just as that nerve makes its exit from the stylo-mastoid
foramen. It passes to the petrosal ganglion of the glosso-pharyngeal.
The branches that arise from the facial nerve after it has passed out
of the stvlo-mastoid foramen are six in number—viz.
THE NERVOUS SYSTEM. 307
The Branch of Communication with the Tympanic Plexus is a small
nerve which connects the geniculate ganglion with the sympathetic tym-
panic plexus.
Tlie Communicating Branch with the Pneumogastric Nerve passes out
of the stylo-mastoid foramen, and communicates with the pneumogastric
nerve through its articular branch.
The Commumcating Branch with the Glosso-pharyngeal Neri^e arises
from the facial as it leaves the stylo-mastoid foramen. It communicates
with the glosso-pharyngeal nerve below its petrosal ganglion.
The branches of the facial nerve before it escapes from the stylo-
mastoid foramen are
1 Stapedius
2. Chorda tympani
3. Connecting branches with pneumogastric nerve
;
4. Connecting branches M'ith glosso-pharyngeal nerve.
The Stapedius or Tympanic Nerve is the most slender branch given
off by the facial nerve. It arises opposite the pyramid of the internal
ear, passes through a fine canal, and is distributed to the stapedius nmscle.
Tlte Chorda Tympani Nerve arises from the facial nerve on the proxi-
mal side of the geniculate ganglion, though apparently it arises back of
the tympanum close to the outer extremity of the aqueduct of Fal-
lopius. From its origin it passes upward in a special curved canal
nearly parallel to the aqueduct of Fallopius, and enters the posterior
wall of the tympanic cavity close to the tympanic membrane. It here
becomes invested by mucous membrane, arches upward between the
long handle of the malleus and the vertical process of the incus to its
anterior angle. It then passes out of the tympanum through a for-
amen (canal of Hugui) at tlie side of the glenoid (Glasserian) fissure,
extends downward on the proximal side of the internal lateral ligament
of the inferior maxillary bone, and forms a union with the lingual
branch of the fifth nerve at a point where the nerve forms an acute
angle by bending forward under the inferior border of the external
pterygoid muscle. It is then distributed to the submaxillary muco-
salivary gland and to the tongue. The chorda tympani nerve receives
a communicating branch from the otic ganglion just before joining the
lingual nerve. There is considerable discussion among anatomists and
physiologists as to the origin and functions of this nerve. Some claim
that it is a continuation of the nerve of Wrisberg, while J. Sapolini
claims it as an independent cranial nerve, entitled to be classed as
the thirteenth cranial nerve. Its function is also still in doubt, some
claiming it to be a motor nerve, others a nerve of sensation, while
others regard it as a special nerve of taste.
The Communicating Brcmch with the Pneumogastric Nerve arises from
the facial nerve a little before its exit from its canal to join the upper
ganglion of the pneumogastric. This branch is not constant.
The Communicating Brcmch with the Glosso-pharyngeal Nerve arises
from the facial just as that nerve makes its exit from the stylo-mastoid
foramen. It passes to the petrosal ganglion of the glosso-pharyngeal.
The branches that arise from the facial nerve after it has passed out
of the stvlo-mastoid foramen are six in number—viz.
