DEGLUTITION. 
Deprefor onguli oris (trizngulayis), is a mufcle.of a 
AMacicnes and triangular fimure, extended from the fide of the 
chin to the corner of the mouth. It has a broad origin 
from the anterior part | 
narrower as it afcends, ‘has its fibres flightly arched towards 
the chin, and terminates at the corner of the mouth by. 
uniting with the zy gomaticus, age anguli, and orbicu- 
laris. Its outer edge is a He ao inferticn to mumercus 
fibres of the platyf{ma myoi by {kin ester- 
naliy, it lies upon the deprefforlabi of aaa se iia 
im- 
{t depre eS i corner t ith, 
portant mufcle, in a phyliognomical point of ca as it 
aéts in all ne ‘fortow!ul emotions. Its effects can be well 
feen in crying. 
Depreffor labii Ai laraare aiid (quadratus.)—It arifes 
from about one 1 anterfor and lateral part of the 
jaw, covered at . origin i the former mufcle. Its fi 
pafs obliquely upwards and — and peice with thofe 
of the oppofite mufcle. It terminates by a broad infertion 
into the lower lip, confounding its Abie with thote of the 
orbic The preceding mufcle, the levator menti, and 
and there is 
ularis. 
the latiffimus colli are alfo conneéted ath it ; 
uch fat m: i ionelon ecie ane 
ternally ; and it covers o 
the mental veffels “and nee st the orbicularis, 
the lower lip down to the 
oe menti (levator propre lab. pe ; Le infes 
It draws 
It elevates and corrugates the chin ; it reftores the 
lower lip, when that has been depreffed. By drawing up 
the chin, it a hi the lower lip, as we fee occafionally in 
{corn and der 
The ira is the largeft mufcle of the lips. It is thin 
but very broad; flattened on its furfaces, nearly quadrilateral, 
m 
ce ob tween the laft grinder, and 
coronoid procefs of the fone jaw. Its fibres purfue a tranf- 
verfe courfe to the lips, and are parallel to each other. They 
terminate under the elevator and depreflor mufcles juft de- 
fcribed, by uniting their fibres with thofe of the orbicularis 
uét of the parotid gland. 
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me 
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¢ 
He 
zygomaticus major, fa rter 
olli, which cover it towards the front, by a confiderabe 
quantity of fat. Its inner is covers the mucous m 
brane of the mouth. It draws the whole of the meer 
backwards, and thereby eras thecheek. It admits of 
sured diftenfion by air or food contained in the mouth, 
and aéts on thofe in various ways. It expels the air in per- 
fons who are bi lowing wind inftruments ; it pufhes the food 
under the teeth in apace or towards the back of the 
tongue previoully to deglutit 
Orbicularis oris (le labial ; , femiombiealae {uperieur and 
es compofing it may be di- 
d hea roper. The firft of thefe 
conftitute the exterior portion of the mufcles, and confift of 
Vou. XI. : 
the unton and intermixture of the various mutcles belonging ts 
he h 
lips: viz levator lubii feperioris et ale nafi, zygo 
ticus minor, and nafalis labii fuperioris above; the cepreffor 
labii inferioris and levator menti i below 3 and the zygematicus 
major, levator anguli cris 
oris at the commitiure, Thefe ; are all fo miugled together, 
that we cannot defcribe any particular courfe of fibres in ny 
portion of the Sibicias. which is formed by their 
‘The proper fibres of the orbicularis are placed ee Ge 
former, ge continuous with them, and correfponding to 
the loofe edge o 118 per : fe) coverca by the 
fin ely, Bet red par e lips o inner 
cumference, and by fe glandule tabisles on eme 
brane towards the mouth, ‘The orbicularis oris is ie anta- 
gonift an all the other mufcles that move the lips, and re- 
ltores thefe parts, when they have been moved out of their 
natural fituation in any direction. It brings them into con- 
tact with each other in an horizontal line, fo as to clofe the 
o When it is neceflary to contract the mouth beyond 
wind sear the or- 
es 
o 
: 
It brings jee me 3 in ie fe c 
round which they may be lie act of {udtion. 
The ation of their exterior fibres tends to evert the edges of 
the lips, fo as to bring the red part more completely into 
There are fometimes conneGted with the mufcles hore 
defcribed cae irregular fibres, which do not exift con- 
ftantly. There is frequently a portion of mu ale les we) 
oe between the right and left platy{ma, juft at t 
e tranfverfus menti of Santorini. Some fibres sriling 
in ‘the ‘cellu lar fubftance over the ma or from the e pla- 
ty{ma myoides, and pafling to of the mouth, 
have been defcribed under the n Soemmer-= 
ring has defcribed by the ane o anomalus maxille fuperi» 
oris, fone irregular fibres, fituated under the levator of the 
ns BPs and inferted by both extremities into the upper 
"Fhe palate Sa the upper furface of the mouth, is 
nearly of a parabolic figure, extending rather more in length 
than in breadth. 
dirary ere a attitude 
completely motionle of infelf, tt aie a ae 
fiftance to the tongue in the motions of aeaiion and de- 
glutition. Tt pnts of a vaulted bony furface, covered by. 
a thick and compact membrane. We mutt diflinguifh in the 
bone the alveolar portion, and the proper palatine arch. The 
ry bones 
rs the palate. The proper 
the oe portions of the 
fuperior maxillary and Sie e bones. 
The palate, when confidered in its perfe&t fate, prefents a 
very confiderable concavity towards the mouth. In the 
child, which has n 
which they were implanted, have been loft, this part of the 
mouth prefents a very different appearance from that which 
has in the intervening periods. It exhibits a nearly level 
furface, inftead of a confiderable concavity. The lower jaw- 
ne undergoes a fimilar change in advanced age ; hence th 
gue becomes very confiderably dimi 
otions of that organ in articulation and 
chewing are proportionally impaired. 
The membrane of the palate prefents a very sonia are 
Na angement 
