PHARYNX. 
and, lastly, is said to arise from the side of the 
tongue near its base: this lingual origin is con- 
sidered by some anatomists as a part of the 
genio-hyo-glossus muscle :* arising thus, the 
superior constrictor winds round the pharynx 
and is inserted into the cephalo-pharyngeal 
aponeurosis, upon which it is placed, and joins 
with its fellow from the opposite side at the 
median raphé. The superior fibres make a 
semicircular sweep upwards towards the spine 
of the basilar process, to which they are con- 
nected by the raphé: the rest pass more trans- 
versely to their insertion and are partially over- 
lapped by the middle constrictor: between the 
upper border of this muscle and the base of 
the skull the pharyngeal aponeurosis is left un- 
covered by muscular fibres. The superior 
constrictor corresponds posteriorly to the cer- 
vical vertebre, and is separated laterally from 
the internal pterygoid by a triangular space 
which is occupied by the internal carotid ar- 
tery, internal jugular vein, and the eighth and 
ninth pairs of nerves: the stylo-pharyngeus 
muscle is also related to its outer side before it 
descends beneath the middle constrictor: by its 
internal surface it is applied upon the levator 
palati and palato-pharyngeus muscles, the mu- 
cous membrane and tlie tonsil. 
The muscular layer thus formed round the 
pharynx is of varying thickness, the greatest 
strength prevailing behind the buccal cavity, 
where the inferior constrictor, in itself the 
strongest of these muscles, overlaps the middle: 
on the other hand, there is but little occa- 
sion for muscular action behind the nasal 
fosse, so we find, in accordance with this 
circumstance, a greater delicacy in the fibres 
of the superior constrictor and a defici- 
ency of muscle altogether higher up: pro- 
bably, also, the overlapping of these muscles 
from below upwards and the oblique direction 
of many of their fibres have reference to the 
downward passage of the food. The margins 
of the constrictors, as these muscles lie on each 
other, are not very distinct, particularly towards 
the back part of the pharynx. Additional mus- 
cular slips have occasionally been observed by 
different anatomists, which may be briefly no- 
ticed :—1. fibres from the petrous process of 
the temporal bone to pass downwards and back- 
walds; 2. from the basilar process directed 
inwards ; 3. from the internal pterygoid plate 
and hamular process directed senawirdl and 
inwards; 4. from the spinous process of the 
sphenoid and from the cartilaginous portion of 
the Eustachian tube. 
Use.—Besides constricting the cavity of the 
pharynx, the inferior and middle constrictors 
can raise the larynx and carry it backwards, 
the latter through the medium of the os hyoides. 
The extrinsic muscles of the pharynx are two 
on either side, the stylo- and palato-pharyngei. 
* Cruveilhier says ‘‘ that those fibres of the 
genio-hyo-glossus, which occupy the interval be- 
_ tween the os hyoides and the stylo-glossus, cover 
the corresponding portion of the pharynx, or rather 
the amygdaloid excavation.” Valsalva and San- 
_ torini regard these fibres as forming a distinct 
muscle, and name it the glosso-pharyngeus. 
947 
Stylo-pharyngeus——This is a long slender 
muscle, broader below than above, and arises 
from the inner side of the styloid process at 
its base, and from the neighbouring part of the 
vaginal process: it descends inwards and for- 
wards towards the greater cornu of the os 
hyoides, and expanding insinuates itself be- 
neath the upper edge of the middle constrictor 
muscle to be applied upon the mucous mem- 
brane of the pharynx: it is inserted with the 
palato-pharyngeus into the posterior border of 
the thyroid cartilage: soon after its origin it 
passes with the stylo-glossus muscle between 
the external and internal carotid arteries, lying 
upon the latter and the internal jugular vein: 
a particular feature in this muscle is its close 
relation to the glosso-pharyngeal nerve, which 
winds round its lower border from behind for- 
wards: as it descends, its next relation is the 
side of the superior constrictor, and passing 
between it and the constrictor medius it is 
applied upon the mucous membrane of the 
pharynx. 
Use.—The stylo-pharyngei raise and widen 
the pharynx, preparing it for the reception of 
the food: they are important muscles in deglu- 
tition: the larynx is also raised by them. 
Palato-pharyngeus—This muscle will be 
again referred to as belonging to the palate: its 
fibres are contained in the fold of mucous 
membrane known as the posterior pillar of the 
fauces : it expands upwards to the soft palate, 
and downwards to the pharynx under the supe- 
rior constrictor: it descends to spread its fibres 
on the mucous membrane, and is inserted with 
the stylo-pharyngeus into the posterior border 
of the thyroid cartilage. 
2. General review of the attachments of the 
pharynz.—By referring to the foregoing de- 
scriptive anatomy of its aponeurosis and mus- 
cles, the pharynx will be seen to form from 
one-half to two-thirds of a vertically elongated 
cylinder, open in front; and although before 
terminating, the interior of the pharynx is con- 
verted into a complete canal, it is so only by 
the relation of a totally distinct organ, viz. the 
larynx. Descending perpendicularly from the 
base of the skull to the lower border of the 
cricoid cartilage, the pharynx is applied evenly 
to the anterior aspect of the bodies of the cer- 
vical vertebrae and deep muscles of the neck, 
having a remarkably loose areolar tissue inter- 
vening, important as preserving to it a perfect 
freedom of motion, while, by its anterior edges, 
it is fixed to the internal pterygoid plates, to 
the pterygo-maxillary ligaments, by means of 
which it is continuous with the lateral walls of 
the mouth, to the inferior maxillary bone, the 
sides of the tongue and cornua of the os hyoides, 
thus forming behind the nasal and buccal cavi- 
ties a large pouch, whose parietes being con- 
stantly strained apart by these attachments, 
preserve a perfectly free cavity, a circumstance 
of considerable importance with reference to 
the continual passage of air to and from the 
respiratory apparatus : continuing downwards, 
the pharynx next embraces the sides of the 
thyroid and cricoid cartilages, but as there is 
no longer occasion for this tension of its walls, 
3 P 2 
