Most digestion occurs when food
reaches the small intestine. As food passes
through the small intestine, it continues
to be broken down by enzymes produced
in the small intestine itself and by those
produced in the liver and passed to the
small intestine. The nutrients broken down
by digestion are absorbed into the body
through the walls of the small intestine.
Blood in tiny blood vessels in the intestinal
walls, called capillaries, picks up the
nutrients from the digested food and takes
them to cells throughout the body where
they can be used. The food is continuously
broken down until the nutrients are in a
form that is usable by the cells of the body