PHARYNX. 
under surface by a dense and thick mucous 
membrane: numerous glands with vessels and 
nerves also enter into its structure. The mu- 
cous membrane covering the bony palate with 
that forming the gums is of a paler colour than 
elsewhere in the interior of the mouth, and is 
united by a remarkably condensed and thick 
submucous areolar tissue to the periosteum, 
especially in the mesial line, where the two 
Structures appear blended: on either side the 
union occurs by fibrous prolongations, allowing 
a thick layer of glands and the vessels and 
nerves of the palate to intervene: the mem- 
brane has a thick investment of epithelial 
scales, and is capable of resisting considerable 
eee of greater thickness before than be- 
ind, indifferently sensible, and in structure 
bears some analogy to that of the skin: the 
glands in every way resemble those of the 
cheeks and lips, and open in like manner upon 
the mucous surface; two larger openings than 
the rest may often be seen on either side the 
median line towards the back part of the 
palate. 
_ The gums (Gr. ovaa, Lat. gingive ) resemble 
in colour and structure the palatine membrane, 
except that the glandular apparatus is here re- 
duced to mere follicular pores. They cover 
either surface of the alveolar processes of the 
jaws, intimately connected with the periosteum, 
and extend a little way beyond the alveoli to 
rest against the necks of the teeth by a festooned 
edge. The denticulated processes of this edge 
are continued across the alveoli between the 
teeth, by which means the gums on either sur- 
face communicate with each other; between 
these processes the concave margin of the gum 
is reflected upon itself to enter the alveoli, 
lining their inner surface, and closely applied 
to the fangs of the teeth. (See Teetu.) The 
palate and gums receive their arterial branches 
from the internal maxillary and facial arteries, 
and their nerves from the spheno-palatine or 
Meckel’s ganglion. (See Firta Parr or 
Nerves.) The palatine nerves gain the palate 
through the anterior and posterior palatine fora- 
mina, and course along immediately beneath 
the periosteum, lodged in grooves, together with 
the accompanying arteries, upon the inferior 
surface of the palatine processes of the superior 
maxillary and palate bone. The palatine arch 
constitutes the septum between the nasal and 
buccal cavities, and forms the fixed and resist- 
ing surface against which the tongue acts in 
deglutition and in the articulation of certain 
sounds; previous to the irruption of the teeth 
and after their decay, the gums are continued 
over the alveolar processes, and by their almost 
cartilaginous hardness supply their place ; they 
are rendered peculiarly soft and spongy by the 
influence of mercury and scurvy upon the 
system. 
The velum palati is a soft moveable curtain 
stretching backwards and downwards into the 
cavity of the pharynx from the posterior border 
of the hard palate, but so continuous with it as 
to exhibit no indication of their union. From 
its oblique direction the buccal or inferior sur- 
face is also anterior; it is concave, prolongs 
951 
backwards the roof of the mouth, and presents 
the median ridge already noticed on the under 
surface of the hard palate. The nasal or supe- 
rior surface looks upwards and backwards, is 
smooth, convex, and continuous with the floor 
of the nasal cavities; these surfaces terminate 
in a thin border posteriorly, which is prolonged 
downwards in the middle line to form the 
uvula. The uvula is of a conical shape, and 
varies in length and size in different indivi- 
duals; it is occasionally found to be bifid at 
its extremity; it gives rise on either side near 
its base to two folds of mucous membrane, 
called the pillars of the fauces, which descend 
diverging towards the sides of the tongue at its 
back part, leaving between them an interval which 
is in a great measure occupied by the tonsil ; 
the anterior pillar proceeds from the base of the 
uvula in front, and arching outwards and down- 
wards terminates at the side of the tongue a 
little in advance of the V-shaped ridge of pa- 
pille ; the two anterior pillars together form 
what is denominated the anterior arch of the 
fauces. The posterior pillars constitute in fact 
the free border of the velum; they are nearer 
to each other at their commencement than the 
anterior, and from this circumstance (although 
on a plane posterior) can be seen at the same 
time with the anterior pillars on looking into 
the mouth ; they spring from the sides of the 
uvula to take an arched course outwards and 
downwards and terminate in the sides of the 
pharynx. The posterior pillars laterally, with 
the velum and uvula above and the base of the 
tongue below, bound the constricted aperture 
between the cavities of the mouth and pharynx, 
which is‘called the isthmus faucium ; the uvula 
dropping in the centre gives the superior out- 
line of this opening a double arched form : it is 
extremely dilatable, and may be contracted 
nearly to complete closure by the muscular 
action of its walls; it is essentially concerned 
in the act of deglutition. The fossa which is 
left on either side between the anterior and pos- 
terior pillars is of a triangular shape, narrow 
above where the pillars approach each other, 
broader and deeper below as they diverge. 
The lower part of this will nearly correspond 
to the angle of the jaw. 
Muscles of the velum palati—These are on 
each side, the circumflexus or tensor palati and 
levator palati mollis, which descend from above 
to be attached to the velum near its upper sur- 
face; and the palato-glossus and palato-pha- 
ryngeus muscles, which descend from it to the 
tongue and palate; lastly there is the central 
azygos uvule muscle. 
The circumflexus palati, tensor palati, or the 
peristaphylinus externus (pterygo-staphylin. 
Chauss.) is a flat, thin muscle, lying to the 
inner side of the internal pterygoid, and with it 
occupying the pterygoid fossa; it arises by ten- 
dinous and fleshy fibres from the scaphoid de- 
pression situated at the upper part of the inner 
pterygoid plate, and extending more outwardly, 
from a part of the external surface of the carti- 
laginous portion of the Eustachian tube. The 
muscle descends, partly tendinous and partly 
fleshy, resting against the outer surface of 
