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All Rights Reserved. International Foundation for Gastrointestinal Disorders. GI Disorders. Upper GI Disorders. Lower GI Disorders. Bowel incontinence Chronic constipation Chronic diarrhea Dyssynergic defecation. Other GI Disorders. Abdominal adhesions Acute Hepatic Porphyria Anal fistulas Celiac disease Clostridium difficile Congenital sucrase-isomaltase deficiency.
Malabsorption Opioid Induced Constipation Radiation therapy injury Scleroderma Short bowel syndrome Superior mesenteric artery syndrome. Vovulus Rare diseases. Motility Disorders. Functional GI Disorders.
The Digestive System. Reality Report from Miranda A. Why is digestion important When we eat such things as bread, meat, and vegetables, they are not in a form that the body can use as nourishment. How is food digested Digestion involves the mixing of food, its movement through the digestive tract, and the chemical breakdown of the large molecules of food into smaller molecules. The third task of the stomach is to empty its contents slowly into the small intestine.
The small intestine has 3 segments: the duodenum, the jejunum, and the ileum. Each part or section performs an important role in nutrient absorption. Production of Digestive Juices The glands that act first are in the mouth — the salivary glands.
Absorption and Transport of Nutrients Digested molecules of food, as well as water and minerals from the diet, are absorbed from the cavity of the upper small intestine. Carbohydrates It is recommended that about 55 to 60 percent of total daily calories be from carbohydrates. Protein Foods such as meat, eggs, and beans consist of giant molecules of protein that must be digested by enzymes before they can be used to build and repair body tissues.
Fats Fat molecules are a rich source of energy for the body. Vitamins Another vital part of our food that is absorbed from the small intestine is the class of chemicals we call vitamins.
How is the digestive process controlled? Hormone Regulators A fascinating feature of the digestive system is that it contains its own regulators. The hormones that control digestion are gastrin, secretin, and cholecystokinin CCK : Gastrin causes the stomach to produce an acid for dissolving and digesting some foods.
It is also necessary for the normal growth of the lining of the stomach, small intestine, and colon. Secretin causes the pancreas to send out a digestive juice that is rich in bicarbonate. It stimulates the stomach to produce pepsin, an enzyme that digests protein, and it also stimulates the liver to produce bile. CCK causes the pancreas to grow and to produce the enzymes of pancreatic juice, and it causes the gallbladder to empty.
Additional hormones in the digestive system regulate appetite: Ghrelin is produced in the stomach and upper intestine in the absence of food in the digestive system and stimulates appetite. Peptide YY is produced in the GI tract in response to a meal in the system and inhibits appetite.
Both of these hormones work on the brain to help regulate the intake of food for energy. Nerve Regulators Two types of nerves help to control the action of the digestive system — extrinsic and intrinsic nerves. Share this page. Share on facebook. Share on twitter. Pancreatitis is inflammation of the pancreas and causes abdominal tenderness and pain. Learn more. What does a gastroenterologist do, and when should you see one?
Here's what you should know before making an appointment. Health Conditions Discover Plan Connect. Understanding Chemical Digestion. Chemical vs. How is chemical digestion different from mechanical digestion?
Where does chemical digestion begin? What path does chemical digestion follow? The bottom line. Read this next. How Is Protein Digested?
How Are Carbohydrates Digested? Jejunum Overview. What's Possible from Microbiome Testing at Home? Food is our fuel, and its nutrients give our bodies' cells the energy and substances they need to work. But before food can do that, it must be digested into small pieces the body can absorb and use. The first step in the digestive process happens before we even taste food. Just by smelling that homemade apple pie or thinking about how delicious that ripe tomato is going to be, you start salivating — and the digestive process begins in preparation for that first bite.
Along the way, food is broken down into tiny molecules so that the body can absorb nutrients it needs:. The digestive system is made up of the alimentary canal also called the digestive tract and other organs, such as the liver and pancreas. The alimentary canal is the long tube of organs — including the esophagus, stomach, and intestines — that runs from the mouth to the anus.
An adult's digestive tract is about 30 feet about 9 meters long. Digestion begins in the mouth, well before food reaches the stomach. When we see, smell, taste, or even imagine a tasty meal, our salivary glands in front of the ear, under the tongue, and near the lower jaw begin making saliva spit. As the teeth tear and chop the food, spit moistens it for easy swallowing.
A digestive enzyme in saliva called amylase AH-meh-lace starts to break down some of the carbohydrates starches and sugars in the food even before it leaves the mouth.
Swallowing, done by muscle movements in the tongue and mouth, moves the food into the throat, or pharynx FAIR-inks. The pharynx is a passageway for food and air. From the small intestine, digested products travel to the liver, one of the body's most versatile organs. Hepatocytes liver cells detoxify filter blood of harmful substances such as alcohol and ammonia. And, hepatocytes store fat-soluble vitamins and excess substances such as glucose sugar for release when the body requires extra energy.
Once food has passed through the small intestine, it is mostly undigestible material and water. It enters the colon large intestine , named for its wide diameter. The large intestine has six parts: the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. The large pouch-shaped cecum marks the beginning of the colon.
Attached near the cecum bottom is the vermiform worm-like appendix. The appendix contains lymphoid tissue and intercepts pathogenic microorganisms that enter the digestive tract. Sometimes, fecal matter may become trapped in the appendix, resulting in appendicitis infection and inflammation.
The other parts of the colon absorb water and minerals from the undigested food and compact the remaining material into feces. Defecation is the digestive process final stage: feces undigested waste products are carried to the rectum through peristalsis and eliminated through the anus. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
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