ANATOMY. 
hranotts bag, called the pharynx. The stir- traneous body should find admission. These 
lace of the mouth is every where covered points are both attained by means of a 
by a soft and smooth membrane. This is of strictly mechanical contrivance ; by a struc- 
course kept constantly in a moist state, as tore which produces the required effect, 
the glands above enumerated continually independently of the will of the animal, and 
pour more or less of their secretion into 
the cavity. The membrane of the mouth is 
continuous with the external surface of the 
body ; but the skin assumes a more delicate 
organization, as must be apparent, to every 
body, from the change of colour at the lips. 
Bag of the pharynx . — The masticated ali- 
ment is collected on the back of the tongue, 
which is then carried upwards, and back- 
wards to discharge it into the pharynx. This 
bag is covered by muscular fibres (forming 
the muscles called constrictores pharyngis) 
which contract, successively, in order to 
propel the food towards the stomach. But 
as there are several organs communicating 
with the pharynx, the food might pass in a 
wrong direction if the parts were not so con- 
trived as to prevent such occurrences. 
In the upper and anterior part of the 
pharynx, the nostrils open by two large and 
free apertures. Between these and the en- 
trance from the mouth, is found a fleshy and 
moveable curtain, called the soft palate, or 
velum pendulum palati. There is a small 
body of a pointed figure projecting from the 
middle of this organ, and known by the 
name of the uvula. This curtain and the 
uvula can be easily seen in the throat of a 
living person. It admits of being elevated 
so as to shut the opening of the nostrils ; and 
its action is exemplified in the act of vomit- 
ing : the food is forcibly thrown into the 
pharynx, and would pass mostly into the 
nose, were it not prevented by the soft 
palate. From the uvula the membrane is 
continued on either side, in an arched form, 
towards the root of the tongue, and it con- 
tains a glandular body called the tonsil, 
which secretes a mucous fluid to lubricate 
the parts, and facilitate the passage of the 
aliment. The larynx opens into the pha- 
rynx, just at the root of the tongue ; over 
this part, which is termed the glottis, every 
morsel of the food must necessarily pass; 
yet, so exquisitely tender is the membrane 
of the windpipe, that the contact of the 
smallest extraneous body excites a convul- 
sive paroxysm of coughing that does not 
cease until the offending matter be removed. 
Here then are two objects to be effected ; 
the function of respiration requires that the 
windpipe should have a free communication 
with the external air, while the irritable na- 
ture of its membrane demands that no ex- 
merely in consequence of those motions 
which the organs perform in the office of 
deglutition. At the back of the tongue, 
and just in front of the glottis, is a cartila- 
ginous valve called the epiglottis. When 
the parts are at rest, this vaive stands per- 
pendicular, and consequently does not inter- 
fere with the passage of air into the wind- 
pipe. In the act of swallowing, the tongue 
is carried backwards, and the windpipe is 
drawn up : hence the epiglottis becomes 
mechanically applied over the opening, and 
at this moment the food enters the pharynx 
over it, and by its pressure closes the aper- 
ture still more completely. As soon as the 
food has passed, the tongue and windpipe 
resume their former position, the elasticity 
of the cartillage restores it to the erect state, 
and the glottis is again free for the continu- 
ance ot respiration. So completely does 
this simple mechanism answer the proposed 
end, that although every morsel of food 
passes over the glottis, the accident of any 
portion going the wrong way, as it is term- 
ed, is comparatively rare, and can only arise 
from our being imprudent enough to laugh 
or talk while we are swallowing. In either 
ot these cases air must pass out of the tra- 
chea, and by so doing, it lifts up the epi- 
glottis. 
The pharynx opens below into the oeso- 
phagus, a muscular tube, which conveys the 
food into the stomach. The aliment in its 
farther progress, goes through different vis- 
cera contained in the abdomen ; and we 
shall therefore proceed with a description of 
that cavity. 
The term abdomen includes a large por- 
tion of the body. It is bounded above by 
the cartilages of the ribs, and by the dia- 
phragm, which separates it from the chest ; 
at the back part, by the bodies of the lum- 
bar vertebra ; in front and at the sides, by 
the abdominal muscles ; and below, by the 
bones of the pelvis. 
It is every where lined by a membrane 
called the peritoneum. The surface of this 
is perfectly smooth and polished, and mois- 
tened by a serous exhalation produced by 
the minute arteries of the part. This mem- 
brane not only lines the cavity of the abdo- 
men, but also covers all the viscera contain- 
ed in that cavity, so that the exterior sur- 
face of each part consists of what anatomists 
