SECTION VII 
THE ALIMENTARY TRACT, PART 2. THE LIVER 
A consideration of the liver is anatomically and 
physiologically the next step in the discussion of diseases 
of the alimentary tract. While this organ may partici- 
pate in most of the pathological states of the tubal part of 
the system, it is comparatively seldom the primary seat 
of change and when damaged seems to be possessed of 
great accommodative and reconstructive power. This 
must be true, and fortunately so, since we ascribe to it 
the major detoxicating function of the body. Neverthe- 
less it is noteworthy that the largest solid organ of 
the animal body shows a relatively low percentage of 
changes threatening to life. In the sense of Pearl's 
method of statistics, it does not *' break down " easily. 
In pathology it is the custom to list with great care all the 
changes, gross and minute, in the liver, but with a few 
exceptions they are secondary or incidental. They do 
however reflect many things, especially referable to diet 
and to chronic infection from the intestinal drainage 
area. It is in these directions that the organ will be 
studied in the following pages. 
Anatomically the liver is situated in the right upper 
part of the abdomen subjacent to the diaphragm in both 
mammals and birds, being held in position by attachment 
to this transverse partition, by ligaments or folds of 
peritoneum, and by the other abdominal viscera. Its 
general relationships do not offer great variations since 
in all animals means are afforded for a dual blood supply 
and an outlet for the hepatic secretion, the bile, into the 
higher intestines. Naturally variations in the size of the 
lobes are observed and there has been considerable spec- 
ulation as to their independence and association. From 
the standpoint of comparative pathology, little can be 
222 
