Gastrointestinal Tract - National Library of Medicine - Pubmed Health

Gastrointestinal Tract - National Library of Medicine - PubMed Health

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Home > Health A – Z > Gastrointestinal Tract Gastrointestinal Tract (GI Tract)

The large, muscular tube that extends from the mouth to the anus, where the movement of muscles, along with the release of hormones and enzymes, allows for the digestion of food. Also called the alimentary canal or digestive tract. PubMed Health Glossary (Source: NIH - National Institute of Diabetes and Digestive and Kidney Diseases)

Related terms: Alimentary canal, Alimentary tract, Digestive tract, Digestive tract structure, Gastrointestinal tract structure

See also: How the Stomach Works, How the Intestine Works About the GI Tract The large, hollow organs of the GI tract contain a layer of muscle that enables their walls to move. The movement of organ walls—called peristalsis—propels food and liquid through the GI tract and mixes the contents within each organ. Peristalsis looks like an ocean wave traveling through the muscle as it contracts and relaxes. Esophagus. When a person swallows, food pushes into the esophagus, the muscular tube that carries food and liquids from the mouth to the stomach. Once swallowing begins, it becomes involuntary and proceeds under the control of the esophagus and brain. The lower esophageal sphincter, a ringlike muscle at the junction of the esophagus and stomach, controls the passage of food and liquid between the esophagus and stomach. As food approaches the closed sphincter, the muscle relaxes and lets food pass through to the stomach. Stomach. The stomach stores swallowed food and liquid, mixes the food and liquid with digestive juice it produces, and slowly empties its contents, called chyme, into the small intestine. The muscle of the upper part of the stomach relaxes to accept large volumes of swallowed material from the esophagus. The muscle of the lower part of the stomach mixes the food and liquid with digestive juice. Small intestine. The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine and push the Parts of the gastrointestinal tract National Institutes of mixture forward to help with further digestion. The walls of the small Health intestine absorb the digested nutrients into the bloodstream. The blood delivers the nutrients to the rest of the body. Large intestine. The waste products of the digestive process include undigested parts of food and older cells from the GI tract lining. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0022855/[8/24/2017 8:42:47 PM] Gastrointestinal Tract - National Library of Medicine - PubMed Health

Muscles push these waste products into the large intestine. The large intestine absorbs water and any remaining nutrients and changes the waste from liquid into stool. The rectum stores stool until it pushes stool out of the body during a bowel movement... NIH - National Institute of Diabetes and Digestive and Kidney Diseases Parts of the lower gastrointestinal tract National Institutes of Health

Related conditions Celiac Disease Appendicitis Diverticulitis Crohn's Disease Gastroesophageal Reflux Disease Irritable Bowel Syndrome Enlarged Hemorrhoids Ulcerative Colitis Gastritis Colon Cancer Rectal Cancer Colorectal Cancer Lactose Intolerance Microscopic Colitis Bowel Obstruction Dysentery Esophageal Cancer Gastroparesis Peptic Ulcer Gastric Cancer Barrett's Esophagus Esophagitis Gastrointestinal Carcinoid Tumor Zollinger-Ellison Syndrome Hirschsprung Disease Malabsorption Syndromes Proctitis Shigellosis Biliary Atresia Gastroenteritis Diarrhea Dysphagia Cryptosporidiosis Short Bowel Syndrome Constipation Fecal Incontinence Whipple Disease Ménétrier's Disease Gastrointestinal Bleeding Diverticulosis Intestinal Intussusception Colon Diseases Inflammatory Bowel Disease Meckel Diverticulum Gastrointestinal Stromal Tumor https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0022855/[8/24/2017 8:42:47 PM] Gastrointestinal Tract - National Library of Medicine - PubMed Health

Anal Cancer Intestinal Volvulus Dumping Syndrome

Terms to know Anus The opening at the end of the digestive tract where bowel contents leave the body. Colon (Bowel) The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus. Enzymes Protein made by the body that brings about a chemical reaction - for example, the enzymes produced by the gut to aid digestion. Esophagus The muscular tube through which food passes from the throat to the stomach. Hormones A messenger molecule that helps coordinate the actions of various tissues; made in one part of the body and transported, via the bloodstream, to tissues and organs elsewhere in the body. Intestines Also called the gut. See large intestine and small intestine. Large Intestine The part of the intestine that includes the appendix, cecum, colon, and rectum. The large intestine absorbs water from stool and changes it from a liquid to a solid form. The large intestine is 5 feet long. Liver The largest abdominal organ. The liver carries out many important functions, such as making important blood proteins and bile, changing food into energy, and cleaning alcohol and poisons from the blood. Lower Gastrointestinal Tract (Lower GI Tract) The lower part of the gastrointestinal tract that includes the jejunum and ileum of the small intestine and the large intestine. Peristalsis A wavelike movement of muscles in the gastrointestinal (GI) tract. Peristalsis moves food and liquid through the GI tract. Rectum The last several inches of the large intestine closest to the anus. Small Intestine The organ where most digestion occurs. It measures about 20 feet and includes the duodenum, jejunum, and ileum. Stomach An organ that is part of the digestive system. The stomach helps digest food by mixing it with digestive juices and churning it into a thin liquid. Upper Gastrointestinal Tract (Upper GI Tract) The upper part of the gastrointestinal tract that includes the esophagus, stomach, and duodenum.

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Celiac Disease Appendicitis Diverticulitis

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Terms to know

https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0022855/[8/24/2017 8:42:47 PM] Gastrointestinal Tract - National Library of Medicine - PubMed Health

Anus The opening at the end of the digestive tract where bowel contents leave the body....

Colon (Bowel) The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one e...

Enzymes Protein made by the body that brings about a chemical reaction - for example, the enzymes produced by the gut...

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