Colon (anatomy)
Front of abdomen, showing surface markings for liver, stomach, and great intestine.
Gray's	subject #249 1177
Dorlands/Elsevier	c_47/12249855

In anatomy of the digestive system, the colon (> Greek κῶλον) is the part of the intestine from the caecum to the rectum. Its primary purpose is to extract water from faeces. In mammals, it consists of the ascending colon, transverse colon, the descending colon, the sigmoid colon, and the rectum. The colon from cecum to the mid transverse colon is also known as the right colon. The remainder is known as the left colon. Diagram of the Human Intestine. ... Elseviers logo Elsevier, the worlds largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. ... Diagram of the stomach, colon and rectum from public domain source at http://www. ... Anatomical drawing of the human muscles from the Encyclopédie. ... For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and... The intestine is the portion of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine. ... In anatomy of the digestive system, the cecum or caecum is a pouch connected to the large intestine between the ileum and the colon. ... The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx. ... Impact of a drop of water. ... Rabbit feces are usually 0. ... Orders Multituberculata (extinct) Palaeoryctoides (extinct) Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Cingulata Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Leptictida (extinct) Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata...

Anatomy

The location of the parts of the colon are either in the abdominal cavity or behind it in the retroperitoneum. The colon in those areas is fixed in location.

Ascending colon

The ascending colon is on the right side of the abdomen. It is the part of the colon from the cecum to the hepatic flexure (the turn of the colon by the liver). It is retroperitoneal in most humans. In grazing animals the cecum empties into the spiral colon.

Transverse colon

The transverse colon is the part of the colon from the hepatic flexure (the turn of the colon by the liver) to the splenic flexure (the turn of the colon by the spleen). The transverse colon hangs off the stomach, attached to it by a wide band of tissue called the greater omentum. On the posterior side, the transverse colon is connected to the posterior abdominal wall by a mesentery known as the transverse mesocolon. The liver is the largest internal organ of the human body. ... The spleen is a ductless, vertebrate gland that is closely associated with the circulatory system, where it functions in the destruction of old red blood cells in holding a reservoir of blood. ... The greater omentum (great omentum; gastrocolic omentum) is the largest peritoneal fold. ... The transverse mesocolon is a broad, meso-fold of peritoneum, which connects the transverse colon to the posterior wall of the abdomen. ...

The transverse colon is encased in peritoneum, and is therefore mobile (unlike the parts of the colon immediately before and after it). More cancers form as the large intestine goes along and the contents become more solid (water is removed) in order to form feces. It is primarily supplied by the middle colic artery, a branch of superior mesenteric artery. The middle colic artery is a branch of the superior mesenteric artery that mostly supplies the transverse colon. ... The superior mesenteric artery arises from the anterior surface of the aorta, just inferior to the origin of the celiac trunk, and supplies the intestine from the duodenum and pancreas to the left colic flexure. ...

Descending colon

The descending colon is the part of the colon from the splenic flexure to the beginning of the sigmoid colon. It is retroperitoneal in two-thirds of humans. In the other third, it has a (usually short) mesentery.

Sigmoid colon

Diagram of the Human Intestine.

The sigmoid colon is the part of the large intestine after the descending colon and before the rectum. The name sigmoid means S-shaped (see sigmoid). The walls of the sigmoid colon are muscular, and contract to increase the pressure inside the colon, causing the stool to move into the rectum. Diagram of the Human Intestine. ... Diagram of the Human Intestine. ... In anatomy of the digestive system, the colon is the part of the intestine from the cecum to the rectum. ... The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx. ... Feces, faeces, or fæces (see spelling differences) is waste product from an animals digestive tract expelled through the anus (or cloaca) during defecation. ...

Due to the intermittent high pressure within it, the colon can develop pockets called diverticuli in its walls. The presence of diverticuli, whether harmful or not, is called diverticulosis. An infection of the diverticuli is called diverticulitis. A diverticulum (plural: diverticula) is medical term for an outpouching of a hollow (or a fluid filled) structure in the body. ...

Sigmoidoscopy is a common diagnostic technique used to examine the sigmoid colon. Sigmoidoscopy is the minimally invasive medical examination of the large intestine from the rectum through the last part of the colon. ...

Function

The large intestine comes after the small intestine in the digestive tract and measures approximately 1.5 meters in length. Although there are differences in the large intestine between different organisms, the large intestine is mainly responsible for storing waste, reclaiming water, maintaining the water balance, and absorbing some vitamins, such as vitamin K. In anatomy of the digestive system, the colon is the part of the intestine from the cecum to the rectum. ... Diagram showing the small intestine In biology the small intestine is the part of the gastrointestinal tract between the stomach and the large intestine (colon). ... Vitamin K denotes a group of 2-methilo-naphthoquinone derivatives. ...

By the time the chyme has reached this tube, almost all nutrients and 90% of the water have been absorbed by the body. At this point some electrolytes like sodium, magnesium, and chloride are left as well as indigestible carbohydrates known as dietary fiber. As the chyme moves through the large intestine, most of the remaining water is removed, while the chyme is mixed with mucus and bacteria known as gut flora, and becomes feces. The bacteria break down some of the fiber for their own nourishment and create acetate, propionate, and butyrate as waste products, which in turn are used by the cell lining of the colon for nourishment. This is an example of a symbiotic relationship and provides about 100 Calories a day to the body. The large intestine produces no digestive enzymes — chemical digestion is completed in the small intestine before the chyme reaches the large intestine. The pH in the colon varies between 5.5 and 7 (slightly acidic to neutral). Chyme is the liquid substance found in the stomach before passing the pyloric valve and entering the duodenum. ... An electrolyte is a substance that dissociates into free ions when dissolved (or molten), to produce an electrically conductive medium. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ... Dietary fibers are the indigestible portion of plant foods that move food through the digestive system and absorb water. ... Impact of a drop of water. ... Subgroups Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are microscopic, unicellular organisms. ... Gut flora, or intestinal bacteria, are the bacteria that normally live in the digestive tract and perform a number of useful functions involving digestion for their hosts. ... Acetate, or ethanoate, is the anion of a salt or ester of acetic acid. ... The propionate (also propanoate) ion is C2H5COO− (propionic acid minus one hydrogen ion). ... The butyrate (also butanoate) ion is C3H7COO- (butyric acid minus one hydrogen ion). ... Common Clownfish (Amphiprion ocellaris) in their magnificent sea anemone (Heteractis magnifica) home. ... A calorie refers to a unit of energy. ... pH is a measure of the acidity of a solution in terms of activity of hydrogen ions (H+). For dilute solutions, however, it is convenient to substitute the activity of the hydrogen ions with the molarity (mol/L) of the hydrogen ions (however, this is not necessarily accurate at higher...

Pathology

An appendectomy in progress.

There are a number of diseases or disorders of the colon: Image File history File linksMetadata Download high resolution version (2048x1360, 786 KB) Summary Licensing File links The following pages link to this file: Appendicectomy Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File linksMetadata Download high resolution version (2048x1360, 786 KB) Summary Licensing File links The following pages link to this file: Appendicectomy Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... An appendicectomy (or appendectomy) is the surgical removal of the vermiform appendix. ...

• Angiodysplasia of the colon
• Chronic functional abdominal pain
• Colitis
• Colon cancer
• Constipation
• Crohn's disease
• Diarrhea
• Diverticulitis
• Diverticulosis
• Hirschsprung's disease (aganglionosis)
• Irritable bowel syndrome
• Polyposis (see also Polyp)
• Pseudomembranous colitis
• Ulcerative colitis and toxic megacolon

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant. An angiodysplasia in the colon being treated with argon plasma coagulation administered via probe through the colonoscope. ... Chronic functional abdominal pain (CFAP) is the ongoing presence of abdominal pain for which there is no physical explanation. ... Colitis is a digestive disease characterized by inflammation of the colon. ... Diagram of the stomach, colon, and rectum Colorectal cancer includes cancerous growths in the colon, rectum and appendix. ... Constipation or irregularity, is a condition of the digestive system where a person (or animal) experiences hard feces that are difficult to eliminate; it may be extremely painful, and in severe cases (fecal impaction) lead to symptoms of bowel obstruction. ... H&E section of non-caseating granuloma seen in the colon of a patient with Crohns disease. ... Diarrhea or diarrhoea (see spelling differences) is a condition in which the sufferer has frequent watery, loose bowel movements (from the ancient Greek word διαρροή = leakage; literally meaning to run through). Acute infectious diarrhea is a common cause of death in developing countries (particularly among infants), accounting for 5 to 8... Diverticulitis is a common disease of the bowel, in particular the large intestine. ... Diverticulosis, otherwise known as diverticular disease, is the condition of having diverticula in the large colon which are outpocketings of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. ... Hirschsprungs disease, or congenital aganglionic megacolon, involves an enlargement of the colon, caused by bowel obstruction resulting from an aganglionic section of bowel (the normal enteric nerves are absent) that starts at the anus and progresses upwards. ... Familial adenomatous polyposis (FAP) is an inherited condition in which numerous polyps to form in the epithelium of the large intestine. ... Polyp of sigmoid colon as revealed by colonoscopy. ... Pseudomembranous colitis is a infection of the colon caused by the bacterium Clostridium difficile. ... Toxic megacolon (megacolon toxicum) is a life-threatening complication of other intestinal conditions. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...

External links

• Overview and diagrams at seer.cancer.gov
• Merck Home 09-118h
• Photo at mgccc.cc.ms.us
• MeSH Large+Intestine
• Virtual Slidebox at Univ. Iowa Slide 393