The stomach is a sac shaped like a "j"
and is about eight inches long. In the stomach, food is
mixed with acids.
The muscles in the stomach move, which helps break down the
food. The stomach is protected from the acid by a lining.
From the stomach, the food pulp is sent to the small
intestine. Food leaves the stomach a little bit at a
The small intestine is the final place
Measuring about twenty feet in length, the small intestine
is one inch in diameter. Digestive juices released in the
small intestine finish breaking down the food.
The food is moved along the small
intestine in a squeezing motion known as peristalsis.
This motion is much the same as squeezing a tube of
toothpaste. All of this movement causes the noise when we
say our stomach is "growling."
Lining the small intestine are millions
of fingers called
villi. These absorb the chemicals
that we need from the food into the body. It is at this
point the food is actually in the body.
Waste products and food that are not
absorbed in the small intestine pass into the large
intestine. This waste material is called feces. The large
intestine is only five feet long but is larger in diameter
than the small intestine. The large intestine includes the
In the large intestine, feces are formed
from water, undigested food and bacteria. Water is absorbed
back into the body so the waste material becomes more solid
as it travels through the colon. It may take as long as
twenty hours for food to pass completely through the large