Rat large intestine is an established model to study the effect of
carcinogens. There are several distinctive features among mammalian gastrointestinal
tracts in gross anatomy but they share some basic similar structures. The variety in
digestive system relies on its physiology. Rats rarely eat high fatty diets, thus the
function of gall bladder become less significant in their digestive system and this is
justified by the fact that rats have none. Rats have large caecum designated for their
fermentation chamber to digest cellulose. Another notable difference is the size and
length of colon itself, in which human colon is significantly bigger and longer. We aimed
to demonstrate the gross anatomy and histology of rat digestive system particularly the
large intestine. (Copied from article).