ASGE Recognized Industry Associate (ARIA) Training Program for Regeneron and Sanofi | June 2023-GI Tract in Health_Small_Large

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The gastrointestinal tract is composed of various digestive organs including the pancreas, esophagus, stomach, gallbladder, liver, small intestine, and large intestine. The small intestine is around 20-25 feet long and plays important roles in digestion, absorption of nutrients, absorption of water, and moving food along the tract. It is divided into three sections: the duodenum, jejunum, and ileum. The duodenum is the first section and shortest segment, where bile ducts and the pancreas empty into for the breakdown of food. The jejunum is the mid-portion responsible for the absorption of nutrients such as carbohydrates, fats, proteins, minerals, and some vitamins. It contains structures called villi, which increase the surface area for absorption. The ileum is the final 8-15 feet of the small intestine and continues the absorption of nutrients, including bile salts and fat-soluble vitamins. The large intestine, or colon, is about 4-5 feet long and functions in the absorption of water and electrolytes, as well as the elimination of solid wastes. Motility in the gastrointestinal tract relies on peristalsis, which is the coordinated contraction and relaxation of smooth muscle to mix and propel food downstream. The rectum retains stool until it is appropriate to be released through the anus. Defecation involves the relaxation of pelvic floor muscles and the voluntary control of the external anal sphincter.

Asset Subtitle

Olufemi Kassim, MD

Keywords

gastrointestinal tract

pancreas

small intestine

large intestine

absorption

villi

bile salts

colon

peristalsis

defecation