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292 ANATOMY.
to the orbicularis palpebrarum, the skin, the conjunctiva of the lower
eyelid, and interlace at the outer angle of the orbit with the malar
branches of the orbital and facial nerves. A branch also passes inward
and interlaces with the external nasal nerve, a division of the oph-
thalmic.
The Nasal or Internal Branches, two or three in number, pass inward
and outward between the fibres of the levator labii superioris al?eque
nasi muscle, and are distributed to the skin of the nose and the lining
membrane of the nostril, and interlace with the nasal branches of the
ophthalmic nerve.
The Labial or Descending Branches are more numerous than the
branches of the other sets from the infraorbital nerve. They pass down-
ward beneath the levator labii superioris muscle, and are distributed to
the up])er lip, its skin, mucous (labial) glands, and mucous membrane.
They also extend to the anterior portion of the gums.
The Infraorbital Plexus of nerves is situated below the orbit, and is
composed of branches from the infraorbital and facial nerves.
The Inferior Maxillary Nerve.
The Inferior Maxillary, or Third Division of the Fifth Nerve, is the
largest of its three divisions. It differs from the other two divisions in
the fact that its function is mixed, being both sensory and motor ; it
also probably supplies in a measure the special sense of taste. This
nerve is distributed to tlie inferior portion of the face, the inferior
maxillary bone, the inferior teeth, a portion of the tongue, and the mus-
cles of mastication. Its origin is composed of two portions, the sensory
and motor.
The Sensory (or larger) Portion arises from the inferior lateral and
anterior part of the margin of the Gasserian ganglion. It passes down-
ward through the foramen ovale in the sphenoid bone, accompanied by
the smaller anterior or motor root. Immediately after its exit from
this foramen the two portions unite, their fibres interlacing, to form one
nerve, the mixed function of the nerve being thus accounted for. It
then descends vertically internal to the external pterygoid muscle, and
divides into two sets of branches, anterior and posterior.
The Anterior Motor Branch or trunk of the inferior maxillary nerve
is the smaller of the tAvo, and is composed almost entirely of motor fila-
ments, which are distributed to the muscles of mastication. It is divided
into four l)ranches
Deep temporal, Pterygoid,
Masseteric, Buccal.
The Deep Temporal Branches are usually two in number, though
occasionally thoi-e are three—anterior, middle, and posterior.
The Anterior Branch l^efore jiiercing the external pterygoid muscle is
joined, by a communicating filament from the buccal nerve. It ascends
across the infratemporal (pterygoid) ridge of the sphenoid bone, passes
to the anterior portion of the temporal fossa, and supplies that part of
the temporal muscle situated in this region.
The Middle Deep Temporal Branch passes outward above the exter-
292 ANATOMY.
to the orbicularis palpebrarum, the skin, the conjunctiva of the lower
eyelid, and interlace at the outer angle of the orbit with the malar
branches of the orbital and facial nerves. A branch also passes inward
and interlaces with the external nasal nerve, a division of the oph-
thalmic.
The Nasal or Internal Branches, two or three in number, pass inward
and outward between the fibres of the levator labii superioris al?eque
nasi muscle, and are distributed to the skin of the nose and the lining
membrane of the nostril, and interlace with the nasal branches of the
ophthalmic nerve.
The Labial or Descending Branches are more numerous than the
branches of the other sets from the infraorbital nerve. They pass down-
ward beneath the levator labii superioris muscle, and are distributed to
the up])er lip, its skin, mucous (labial) glands, and mucous membrane.
They also extend to the anterior portion of the gums.
The Infraorbital Plexus of nerves is situated below the orbit, and is
composed of branches from the infraorbital and facial nerves.
The Inferior Maxillary Nerve.
The Inferior Maxillary, or Third Division of the Fifth Nerve, is the
largest of its three divisions. It differs from the other two divisions in
the fact that its function is mixed, being both sensory and motor ; it
also probably supplies in a measure the special sense of taste. This
nerve is distributed to tlie inferior portion of the face, the inferior
maxillary bone, the inferior teeth, a portion of the tongue, and the mus-
cles of mastication. Its origin is composed of two portions, the sensory
and motor.
The Sensory (or larger) Portion arises from the inferior lateral and
anterior part of the margin of the Gasserian ganglion. It passes down-
ward through the foramen ovale in the sphenoid bone, accompanied by
the smaller anterior or motor root. Immediately after its exit from
this foramen the two portions unite, their fibres interlacing, to form one
nerve, the mixed function of the nerve being thus accounted for. It
then descends vertically internal to the external pterygoid muscle, and
divides into two sets of branches, anterior and posterior.
The Anterior Motor Branch or trunk of the inferior maxillary nerve
is the smaller of the tAvo, and is composed almost entirely of motor fila-
ments, which are distributed to the muscles of mastication. It is divided
into four l)ranches
Deep temporal, Pterygoid,
Masseteric, Buccal.
The Deep Temporal Branches are usually two in number, though
occasionally thoi-e are three—anterior, middle, and posterior.
The Anterior Branch l^efore jiiercing the external pterygoid muscle is
joined, by a communicating filament from the buccal nerve. It ascends
across the infratemporal (pterygoid) ridge of the sphenoid bone, passes
to the anterior portion of the temporal fossa, and supplies that part of
the temporal muscle situated in this region.
The Middle Deep Temporal Branch passes outward above the exter-
