ANATOMY. 
call its peritoneal coat. Hence the motions 
of these parts upon each other, and upon 
the surface of the' cavity are performed with 
perfect facility. The productions of the 
membrane, which give these exterior invest- 
ments to the viscera, serve also to confine 
them in their relative positions. 
The cavity is subdivided into three regions, 
the epigastric, which includes all the space 
above an imaginary line drawn across the 
belly, from the greatest convexities of the car- 
tilages of the seventh true rib; the umbilical, 
which is the division between this line and 
another drawn from the anterior superior 
spines of the ilia ; and the hypogastric, which 
is the space left below the last line. 
The sides of the epigastric region, which 
are the spaces covered by the cartilages of 
the libs, are called hypochondria : the sides 
of the umbilical region are named the loins : 
and those of the hypogastric the groins. 
The stomach is a large membraneous reser- 
voir, receiving the food from the (esophagus, 
and retaining it until a certain change, called 
digestion, is produced. Its figure is conical, 
as it is largest at the left end, and gradually 
decreases in size towards the right: these 
are called the greater and smaller extremi- 
ties of the stomach. It is also bent in its 
course, so that we describe a greater and 
smaller curvature or arch. It has two open- 
ings, one close to the diaphragm, called the 
cardiac, superior, or cesophageal ; the other 
just at the smaller end is called the pyloric, 
or lower orifice. The capacity of the stomach 
varies from about 5 to 1 1 pints. 
Its structure is muscular; and this is 
necessary in order to propel the food when 
digested. Under the muscular coat is found 
the internal, or villous tunic, the arteries of 
which pour out the gastric juice, the chief 
agent in the digestion of tiie food. 
The pylorus, which word is derived from 
two Greek terms, signifying the keeper of 
the gate, is a contracted ring, by which the 
stomach communicates with the small intes- 
tine. It prevents the food from passing 
out of the stomach, before it has been suffi- 
ciently acted on by the gastric juice. 
The stomach receives a portion of peri- 
toneum as the oesophagus passes the dia- 
phragm. There is also a process coming 
from the liver, called the lesser oprentum, or 
mesogaster. This is attached to the lesser- 
arch of the stomach. The great omentum, 
or the caul, is affixed to the greater arqh of 
the stomach, and hangs from thence over the 
surface of the intestines ; being interposed 
between them and the intestines. It is also 
attached to a part of the colon; its use i* 
unknown. 
The small intestine is divided into three 
parts ; the duodenum, jejunum, and ileum: 
but this distinction is an arbitrary one, and 
not founded on any difference in structure. 
It consists of a membr anous tube, about an 
inch or an inch and a half in diameter, and 
four times the lengtir of the subject. Not- 
withstanding this great length, it is collected 
by means of numerous turnings and convo- 
lutions, into a comparatively small space. 
These convolutions of the small intestine 
occupy the chief part of the umbilical and 
hypogastric regions of the abdomen. They 
are connected in their situation by means of 
a broad folded membrane, called the mesen- 
tery. This production of the peritoneum 
is about six inches broad at its commence- 
ment, but it expands gradually, something 
after the manner of a fan, so that it becomes 
broad enough, ultimately, to cover the 
whole length of the small intestine. It 
serves to keep the different convolutions of 
the canal in a certain relative position, and 
allows, at the same time, a considerable 
freedom of motion, without any danger of 
intangling. In tracing the course of the 
small intestine, we follow the duodenum 
from the lesser extremity of the stomach, 
in the right hypochondrium, making three 
turns close on the backbone, and then com- 
ing out just over the left kidney. The 
general direction of the canal from this point, 
independently of its various turnings and 
windings, is towards the right groin, where 
the ileum terminates by entering the coecum. 
The small intestine possesses three coats 
similar to those of the stomach : viz, an ex- 
ternal or peritoneal ; a middle or muscular ; 
and an internal or villous tunic. The latter 
forms a great many transverse, loose, and 
floating processes, called valvulae conniven- 
tes ; by means of which the extent of surface 
of the villous coat is very much augmented. 
Numerous glandular bodies are found in 
parts of the canal, collected into small par- 
cels, and hence called glandulas agminatEe. 
The food which is reduced by the action 
of the stomach into an homogeneous mass, 
called chyme, enters the small intestine, 
where it undergoes a further change, and 
becomes chyle. It is propelled along the 
canal by the muscular coat of the intestine, 
and the villous tunic absorbs from it the 
nutritions particles. It passes along every 
turn and winding of this long canal, continu- 
ally subjected to the action of the absorbing 
vessels. The residue of the alimentary mat- 
