Ed Golson Outdoor Education

Digestive system

The purpose of this system is just as it sounds, to digest. The things we normally eat and drink are not ready to be directly used by the body.  The digestive system breaks down the food and drink that we take in our bodies into its basic components so that we may use it for nourishment and energy. The total process from eating food to excreting wastes takes about 24 hours to complete.  There are many organs that are used in this process.

The mouth is where digestion begins. When you eat something, your teeth grind and tear up the food to make it easier to swallow and digest. Saliva, which contains many types of digestive enzymes, is also excreted onto your food while in your mouth.  Once you swallow the food, it enters a mucus lined tube called the esophagus.

From the esophagus, the food empties into the stomach.  Here three major tasks take place.  First the stomach must release digestive juices, including enzymes and acids, to help break down the food.  Second the stomach must use its muscle action to mix everything up.  Third the stomach must slowly push food into the small intestine. 

In the small intestine, more digestive juices and enzymes are released from the pancreas and the glands from the wall of the small intestine and used to break the food down even farther. Also the nutrients that have been broken down enough are secreted through the walls of the small intestine and enter the bloodstream. After the food travels through the many feet of small intestine it enters in the large intestine.  Here more juices are added, this time it is bile from the gall bladder.  The liver produces this green liquid and empties it into the gall bladder where it is stored until digestion.  Also in the large intestine the rest of the nutrients are absorbed into the bloodstream. The large intestine also removes excess water from what is left of the food to use in the rest of the body. Finally the undigested food, usually fiber, is pushed to the colon which holds it until we have a bowel movement where the food is released through the anus. 

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