how does a digestive system break down foods?

Digestion is the breaking down of foods into a form that our body can use. This is the process of food through the digestive system or gastrointestinal tract, and undergoes three processes as a summary of the process of food: absorption, elimination, and digestion.

Even before you take your first bite of food, your stomach is getting ready to digest your food, and will be digesting it for the next couple of hours or days, depending on what you ate. This process of digestion is how your body allows you to absorb the nutrients and energy from the food you eat.

When you first smell a food, or maybe even think about it, your mouth produces saliva, which helps to break down chemicals in the food. When you are done chewing, your tongue pushes the food down the throat into the stomach.The stomach has three jobs which is to store the food that has been eaten, break down the food into a liquid, and to slowly empty the liquid into the small intestine. To keep the stomach from digesting itself, it is lined with a thin membrane called mucousa, and that secretes a protective, slimy covering of mucus. The muscles of the stomach mix all the food together with gastric juices, which help to kill any bacteria that might have been in the food. This thick liquid is called chyme.

The small intestine, which is actually the most important step of digestion (not the stomach!), is about one to two inches around, and is right below the stomach. If you stretched out an adult's intestine, it would be over twenty-two feet long. The small intestine serves to break down food even further, so that your body can absorb all the proteins, carbs, fats, etc. that it needs. The pancreas, gallbladder, and liver also help in this. The pancreas produces juices that help to digest fats and proteins. Bile from the liver absorbs fats into the bloodstream, and the gallbladder stores the bile, until it is needed by the liver.

All the nutrients then travel to the liver, while everything else that has not been digested goes to the large intestine.

Next is the large intestine, where all the food that cannot be digested goes. Since it cannot be digested, it must leave the body; but before it goes, it passes through a part of the large intestine called the colon, which is where the body gets its last chance to absorb some of the nutrients from it that are left. Once it is done, it becomes a solid, and exits the body.