An Overview of the Digestive System

The major function of the digestive system is to break down food so that the nutrients can be absorbed into the bloodstream. 

The digestive system begins at the mouth, where food is chopped and chewed by the teeth into small pieces. Saliva moistens the food to make swallowing easier. As the food is swallowed, it then passes down the esophagus and into the stomach.

The stomach muscles churn and mix the food with acids and enzymes, breaking it into smaller pieces, until it eventually becomes a thick liquid. It is then moved into the small intestine. In the small intestine some of the nutrients (and also water) are able to pass through the intestinal wall into the bloodstream to be distributed throughout the body.

The remaining food and water continues to be moved into the large intestine. By this stage, most of the absorption of nutrients has taken place already. The primary function of the large intestine is to absorb the remaining water.

The remaining matter (now called feces) are then moved into the rectum and stored there. Feces exit the body through the anus.

Accessory digestive organs
Other organs that help with digestion include:

The liver secretes a digestive juice called bile into the small intestine, or into the gallbladder to be stored. Bile helps to digest lipids in the small intestine.

The gall bladder stores bile and then supplies it to the small intestine when required.

The pancreas secretes digestive juices and digestive enzymes into the small intestine.