LIVER
The liver is a large organ weighing between 1.4 - 1.6 kg. It has a wide variety of functions including energy storage, protein production, metabolism of fats and toxins, and production of biochemicals necessary for digestion. The liver produces bile, which aids in the digestion of fats by emulsifying them in the small intestine. Common conditions that can affect the liver include non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, autoimmune liver disease, viral hepatitis and primary and secondary cancers of the liver.
PANCREAS
The pancreas is a secretory organ that produces both digestive enzymes and important hormones such as insulin. Pancreatic fluid containing digestive enzymes is released into the small intestine in response to eating. These enzymes further break down proteins, carbohydrates, fats and other nutrients before they are absorbed. Common conditions that can affect the pancreas include gallstone pancreatitis, pancreatic insufficiency and cancers of the pancreas.
GALLBLADDER
The gallbladder is a small pouch-like organ that stores and concentrates bile produced by the liver. In response to a meal containing fat, the gallbladder contracts and releases bile into the duodenum. Common conditions that can affect the gallbladder include gallstones and infection (cholecystitis).
STOMACH
The stomach is a muscular bag made up of three parts, the fundus, the body and the antrum. The stomach produces acid, which aids digestion and acts as a defence against harmful microbes. The stomach also acts as a reservoir following a meal, releasing the partially digested meal in a slow and steady fashion into the small intestine. Common conditions that affect the stomach include gastritis, Helicobacter pylori infection, peptic ulcer disease and cancers of the stomach.
APPENDIX
The appendix is a small blind ended tube arising from the first part of the colon (the caecum). Its function is unclear, some believe it is a redundant remnant from our primate ancestors, while others believe it is a repository for useful bacteria and has an immunomodulatory role. Common diseases of the appendix include appendicitis and carcinoid tumours.
SMALL INTESTINE
The small intestine is the long thin muscular tube extending from the stomach to the colon (large intestine). It comprises three parts, the duodenum, jejunum and ileum and ranges in length from 4.5m to 9.5m. Most of the digestion and absorption of food takes place in this part of the gastrointestinal tract. Common conditions that affect the small intestine include peptic ulcer disease (duodenum), coeliac disease, Crohn's disease and some infections. Cancers of the small intestine are relatively rare.
COLON
The colon (large bowel) is the final part of the gastrointestinal tract. Its main function is to remove water and salt from the waste matter of digestion before excretion. There is a vast number of bacteria (100 trillion) that reside in the colon. These bacteria help to ferment and extract nutrients that could not otherwise be harvested. Common conditions that can affect the colon include colonic polyps, diverticular disease, ulcerative colitis, Crohn's disease and colorectal cancers.
