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192 ANATOMY. ;

side of the tongue as far as the tip, blending with the fibres of tlie lin-
gualis in front of the hyo-glossus.
TJie Oblique Portion passes slightly downward over the hyo-glossus, its
fibres interlacing with those of that muscle and those of the palato-glossus.
Relations.—On its lateral surface the stylo-glossus is associated with
the parotid gland, the internal pterygoid muscle, sublingual gland, gus-
tatory nerve, and mucous membrane of the mouth ; the internal sur-
face with the tonsils, the superior constrictor of the pharynx, and the
hyo-glossus muscle.
Variations.—The muscle has many variations, sometimes being absent
at others it has been found to be double. It may receive slips or may
arise entirely from the angle of the jaw, the stylo-maxillary ligament,
the internal pterygoid muscle, or the tympanic portion of the temporal
bone. Slips may pass to the pharynx.
Nerves.—Its nerve-supply is derived from the hypoglossal.
Action.—To assist in retracting; and elevatinsr the tono-ue.

THE MUSCLES OF THE PHARYNX AND THE SOFT PALATE.
This group (Fig. 96) includes the superior constrictor, middle con-
strictor, inferior constrictor, stylo-pharyngeus, palato-pharyngeus, palato-
glossus, palato-Eustachian or
Fig. 96. tensor palati, levator palati,
and azygos uvulae.
The Hiuperior Constrictor
muscle of the pharynx is a
thin quadrilateral muscle, sit-
uated, as its name implies, at
the upper portion of this mus-
cular pouch : its fibres are paler
than those of the middle and
inferior muscles. It arises,
commencing from above down-
ward, from the lower third of
the free margin of the internal
pterygoid plate and its hamu-
lar process, the tuberosity of
the palate bone, the reflected
tendon of the palato-Eusta-
chian or tensor palati muscle,
and the ptervgo-maxillary liga-
ment—at which point some
of its fibres are continuous
from the buccinator ; it also
arises from the posterior ex-
tremity of the mylo-hyoid
ridge, the mucous membrane
of the mouth, and the sides of
the tongue continuous -with the
Muscles of the Pharynx external view. gCuio-gloSSUS mUScls. The