DEGLUTITION. 
a eae ele which is lodged for the greateft part in the 
body of the mufcle, but comes out 
planted into the apex, the outer and inner margin, and the 
anterior edge of the coronoid procefs. 
1e mufcle is thin above, and grows Spica eal 
downwards; it is nearly flat on its two furface 
e tempo d by the 
aponeurofis of the eeeasrac a ay ee y the anterior and 
fuperior mufcles of the ear; by the fuperficial temporal vel. 
fels a nerves; the zygomatic arch and the maffeter 
mu 
Tt clevates the lower jaw, particularly when ating in con- 
junction with the maffeter. If ie bone has been carried 
e emaoem 
externus in carrying ihe jaw ae 
he moffeter (ugo-maxilien) isa a hone and thick mutcle, 
compofed of an intermixture of tendinous and mufcular 
two thirds of the anterior and outer part of the lower edge 
of the zygoma, by a very which, 
mixture 
zygoma by fhort ie Ce fibres. The firtt portion con- 
ftitutes the chief bulk of the mufcle, and, pafling obliquely 
downwards and backwards, is — into the angle an 
neighbouring portion of the r of the lower jaw. The 
aie of the fecond clafs, eae vertically, are mixed 
vith the former at their infertion. divifion paffles 
ebigul — oe are re inferted Aa up in the ramus of 
the jaw and near the 
ae ‘" the piaty{ma m 
cides, the parotid gland and i aly aie june the facial 
nerve, tran{verfalis facigi artery, zygomaticus and orbicu 
laris palpebrarum mufcles. It covers the ramus ef the 
lower jaw, which is rendered ied rat ao = by the 
attachment of the on of the 
buccinator by adipo ous fubttan 
It elevates the lower jaw, ee is particularly employed on 
thofe occafio 
e 
thofe elevations of the part, which 
ene not 1 require fo ee an exertion, as in {pea 
poral mufcle is made ufe of. The outer and larger part may 
contribure flightly to move t w forwards, while the 
fibres w Is 
temporal, or the pterygoideus ale 
exerted in deprefling the head, fuppcfing the lower jaw 
be carried downwards, and to ation ? 
a3 and are peculiarly fubject to the 
attacks of tetanus. Parsi, on the contrary, flow in 
affeGting them ; and they will be found often to aé& equally 
well on bo th fides, when the whole face is diftorted from 
hemiplegia 
Prerygoideus — ( ager one is placed on the 
infide of the s of the jaw, oppofite to the maffeter, to 
which in Sgr, od fae it hasa lr wand: 
although it is rather {maller in fize. ending part of 
the lower leu is indeed included Gegera the fibres of 
this mufcle and the maffeter ; although the latter embraces it 
moreclo aa onthe outtide, than the pterygoid does internally. 
Its diftinguifhing epithet of iaternus denotes merely that it 
“arifes from a more internal part of the eel a proceis 
than the externus, and not that it is fituated m eeply. 
It arifes ie the whole of the pterygoid ae “confequently 
from the inner furface of the external, and from the outer 
furface of Ge internal plate, and from the ptery edi procefs 
Its fibres, confifting, like thofe of the maf 
n and mufcle, defcend 
2} 
me 
co 
o 
© 
le) 
n 
ae] 
p 
c. 
fe) ee and are Cae 
mixed, under the edge of the bone, with thole of the raat. 
feter. 
lower jaw it affifts in mo one towards the 
ae or left, a it acts feparate 
The th airs © oo now w defcribed unite in pros 
and nae teeth, heir 
aoiees of their offic i 
evinced by various inftances of exertion, Vefalius mentions: 
a man who 
five: pounds weight held in the mouth, fo as to it in ® 
beam at the diftance of thirty-nine fect ; and canes are 
not uncommon of perfons balancing on the chin a plank or 
ladder fo heavy c. they can barely lift it. Haller has col- 
le&ted feveral examples, as the elevation of a malt, and placing 
it on the fhoulders: ofa table fix feet broad, with a gee 
of 60 pounda, hanging to the oppofite fide; a 
pounds weight, &c. We muft recolleé alfo that dicte eX= 
ertions require much greater force than the weights would 
eats = indicate ; fince the mufcles are all inferted near the 
of motion, and the force aéts at a confiderable diflance 
fom Ae lever ; hence it has been calculated that the whole 
power would be equal to 1000 or 1800 pot unds. Man, there= 
fore, is admirably provided with i urating the 
food, more powerful indeed lg feems pe for the re- 
dudtion ef aliments, ab sh the various arts of cookery. 
Yet thefe are trivial c okey to a ftrengih of the peo 
ponding mufcles in peice animals, where the jaws co 
ftitute moft terrible inftruments of attack and defence, ad 
are able to comminute the bones, which are {wallowed with 
the i of the prey. 
terygoideus externus a cee is a thick mufcle, 
glee obliqu ah between rs pte d procefs and the con- | 
dyle of ne low w. arifes ae oe outer furface of 
the external pie eo ga from the ouring part 
of the os palati, and from the {phenoid Bone aes the tem 
poral foffa. Its fibres pafs obliquely backwards and outwards, 
and are jnferted into the foflicula of the front of the con- 
dyle, 
