What Happens to Food After It Leaves the Stomach?

The mixture of partially digested food drenched in acidic stomach juice is slowly sent into the small intestine. This portion of our digestive tract is the location of the majority of digestive enzyme activity and the absorption of nutrients. The wall of the small intestine presents a very sophisticated pattern of folds and projections. This design allows the small intestine to have an absorptive surface approximating the size of a tennis court. This allows for very efficient absorption.
 

When the food mixture is spurted into the small intestine from the stomach, it hardly resembles what we ate. Yet most of the nutrients still need further digestion to reach their absorbable state. First, bicarbonate produced by the pancreas enters the small intestine and neutralizes the acidic food mixture draining from our stomach. Then digestive enzymes that are also produced by our pancreas and bile from the gallbladder and liver make their way to the small intestine as well. These factors, along with digestive enzymes produced by the cells that line the small intestine, will complete digestion.