The following illustration shows a simple illustration of a normal gastrointestinal tract.
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Esophagus |
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2. |
Abdomen |
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Stomach |
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4. |
Pylorus |
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5. |
Duodenum |
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6. |
Jejunum |
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7. |
Ileum |
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8. |
Large intestine |
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In order to understand how bariatric surgery results in weight loss, it is necessary to understand how food is digested. After swallowing, food enters the stomach, which holds the food. The stomach then allows small amounts of the food to pass further into the digestive tract. The volume of the stomach is usually between 600 and 1000 cc, or 20 to 30 ounces.
In the first part of the small intestine, or duodenum, food comes into contact with bile which is secreted by the liver, as well as enzymes from the pancreas. These secretions help in the digestion and absorption of food. Most of the iron and calcium in the foods we eat are absorbed in the duodenum.
The jejunum and ileum, the remaining two segments of the nearly 20 feet of small intestine, complete the absorption of almost all calories and nutrients. Food particles that cannot be digested in the small intestine are stored in the large intestine until eliminated.
Sources:
www.yoursurgery.com
www.niddk.nih.gov
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| Photo used with permission from Ethicon Endo-Surgery, Inc. |
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