∗ Series of hollow organs joined in a long twisting tubefrom the mouth to the anus. Other organs areinvolved that help the body break down and absorbfood.∗ Made up of: mouth, esophagus, stomach, smallintestine, large intestine(also called the colon)rectum, and anus.Made up of the digestive tract
• Begins in the mouth where food enters and is partiallybroken down by chewing and by the salivaryenzymes.• After chewed and swallowed, the food enters theesophagus. The esophagus is a long tube that runsfrom the mouth to the stomach. In order for the foodto get from the mouth to the stomach, the esophagususes rhythmic, wave-like muscle movements (calledperistalsis).Process
∗ Once it reaches the stomach, the food is churned andbathed in gastric acid. Food in the stomach that ispartly digested and mixed with stomach acids is calledchyme.∗ When the food is finished breaking down in thestomach, it then enters the duodenum, which is thefirst part of the small intestine.
∗ It then enters the jejunum and then the ileum (thefinal part of the small intestine). In the small intestine,bile (produced in the liver and stored in the gallbladder), pancreatic enzymes, and other digestiveenzymes produced by the inner wall of the smallintestine help in the breakdown of food.
∗ Food then passes into the large intestine.∗ Some of the water and electrolytes (chemicals like sodium) areremoved from the food there.∗ Bacteria like Bacteroides, Lactobacillus acidophilus, Escherichiacoli, and Klebsiella in the large intestine help in the digestionprocess.∗ The first part of the large intestine is called the cecum, which theappendix is connected to.∗ Food then travels upward in the ascending colon. The foodtravels across the abdomen in the transverse colon, goes backdown the other side of the body in the descending colon, andthen through the sigmoid colon.
∗ Finally, solid waste is then stored in the rectum until itis excreted via the anus.
∗ Crohn’s Disease: It is a type of inflammatory bowel disease thatcan affect any part of the gastrointestinal tract from the mouthto the anus. It has a wide variety of symptoms, including:abdominal pain, diarrhea, or weight loss. Also outside thegastrointestinal tract it can cause skin rashes, arthritis,inflammation of the eye, tiredness, and lack of concentration.∗ Caused by interactions between environmental, immunologicaland bacterial factors in genetically susceptible individuals.∗ Results in a chronic inflammatory disorder, where the bodysimmune system attacks the gastrointestinal tract possiblydirected at microbial antigens.Diseases in the Digestive System
∗ Gastroesophageal reflux disease (GERD): Chronicsymptom of mucosal damage caused by stomach acidcoming up from the stomach into the esophagus.∗ Caused by changes in the barrier between thestomach and the esophagus, which normally holdsthe top of the stomach closed. It can also be causedby an impaired expulsion of gastric reflux from theesophagus, or a hiatal hernia. These changes caneither be temporary or permanent.