Stomach & Esophagus

The stomach and esophagus work in very close proximity and are the site of the greatest differentiation between ruminants and

nonruminants (Campbell 1975). The muscles and linings of the esophagus are constructed to be impermeable and they also usher

food into the rest of the digestive tract (Stevens 2008). A key fact to note is that in ruminants the esophagus will also transport the

food back into the oral cavity (Baldwin 1984). A ruminants stomach is split into a few different compartments, as can be seen in

Figure 2. These are the rumen, reticulum, omassum, and abomasum (Baldwin 1984). The abomasum is comparable to the stomach

found in nonruminants in that it is a gastric compartment. The omassum absorbs water that makes its way into the stomach and

diffuses it to the rest of the organism. The rumen and reticulum are the largest compartments of the ruminant stomach, accounting

for up to 85% of the stomach's storage capacity (Baldwin 1984), and serve as an anaerobic environment in which bacteria can

be sheltered from oxygen and break down the food that moves in (Wolin 1981).

Please email Brian McRae at Davidson College with any questions.

This website was created as a part of a class project in the Animal Physiology Class at Davidson College.