118 
ELEMENTS OF MAMMALIAN ANATOMY. 
verse extends crosswise, connecting the ascending with the 
descending, which lies on the left side. 
antatssen 
nadia baal 
deh tl 
Fic. 63. A  Cross- 
SECTION OF THE Mu- 
cous CoAT OF THE 
STOMACH BETWEEN 
THE LINES a@ AND € 
IN Fic. 60 SHOWS 
A GaAstTRIC GLAND. 
x 250. Diagram- 
matic. 
a, Mouth of gastric 
gland; e¢, columnar 
epithelial cells on 
the food surface of 
the stomach; J, lu- 
men of a gland; o, 
oxyntic or acid cell. 
acts on the sugars. 
cous membrane is 
The descending 
colon terminates in the rectum, which 
is five or six centimeters long. 
The wall of the alimentary canal 
is composed of three chief coats—nui- 
areolar, and muscular. These 
coats may be seen by cutting trans- 
COUS, 
versely, with a sharp scalpel, a portion 
of the stomach hardened in formalin. 
The mucous coat (Fig. 62) lines the 
contains the 
glands which vary much in the differ- 
ent portions of the canal. The esoph- 
agus contains the esophageal glands, 
whose secretion probably has no other 
effect on the food than to facilitate its 
passage. The mucous coat of the 
stomach contains the gastric glands, 
which yield pepsin and hydrochloric 
acid, the chief agents of the gastric 
digestive fluid (Fig. 63). The glands 
in the cardiac end of the stomach differ 
from those in the pyloric end in con- 
taining numerous parictal or acid cells 
which probably secrete the hydro- 
chloric acid for digestion. 
The mucous coat of the small intes- 
tine contains tube-like glands, the 
glands of Lieberkthn, whose secretion 
In the duodenum and jejunum the mu- 
lumen and numerous 
thrown into numerous transverse folds, 
valvuli conniventes, which increase the surface for absorp- 
tion. 
The willi are minute finger-like processes (Fig. 64), 
