The latter correspond with three infoldings called transverse rectal folds. The rectum has a characteristic S-shape marked by several bends or turns sacral, anorectal and lateral flexures. The roles of the rectum include temporary storage of fecal matter and defecation. The typical characteristics of the large intestine (taenia coli, haustra, epiploic appendages) change or even terminate at the rectum. The rectum stretches between the rectosigmoid junction and the anal canal. It is connected to the pelvic wall by the sigmoid mesocolon. This part of the colon is intraperitoneal. The S-shaped sigmoid colon travels from the left iliac fossa until the third sacral vertebra ( rectosigmoid junction). Toldt’s fascia fixes the descending colon to the posterior abdominal wall. This part of the colon is retroperitoneal. The left paracolic gutter is located between the descending colon and the lateral abdominal wall. It travels through the left hypochondriac region, left flank and left iliac fossa. The descending colon extends between the left colic flexure and sigmoid colon. The appendix has a role in the maintenance of gut flora and mucosal immunity.Īre you curious to find out more about the cecum and appendix, and how they can be located inferior to the liver? Details are provided below: These two parts of the large intestine are connected by the meso-appendix. The vermiform appendix is a blind lymphoid pouch located in the right iliac fossa which arises from the cecum. The functions of the cecum involve temporary storage of chyme, and fluid and electrolyte reabsorption. An ileocecal valve regulates the passage of intestinal contents from the small into the large intestine. The folds fuse together around the orifice, forming the frenula of the ileal orifice, which prevents reflux of cecal contents into the ileum. The ileocecal orifice is marked by the ileal papilla, which consists of two folds called ileocecal lips (superior, inferior). The terminal ileum joins the cecum at the ileocolic junction. The cecum is intraperitoneal with various folds and pockets ( retrocecal peritoneal recesses) surrounding it. The cecum is the first part of the large intestine, lying in the right iliac fossa of the abdomen. The middle four sections (ascending to sigmoid parts) form the colon.Īn overview is provided in the following study unit: The large intestine consists of eight parts the cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anal canal. The mnemonic ' Eva Has Ten Socks' stands for: There is a very simple way to remember these features specific to the large intestine. They are created by semilunar folds on the internal surface of the large intestine.
Haustra are sacculations that occur along the large intestine, providing it with its characteristic ‘baggy’ aspect. Their contractions facilitate the peristaltic action of the large intestine, propelling the fecal matter and forming the haustra. Teniae coli are three longitudinal bands of smooth muscle located underneath the peritoneum that extend along certain sections of the large intestine. Omental or epiploic appendages are fat filled pouches of peritoneum that are attached externally to the walls of the large intestine. The large intestine has several distinct anatomical characteristics the omental appendices, teniae coli and haustra. In this article we’ll explore the anatomy, blood supply and innervation of the large intestine.
Sympathetic & parasympathetic: aortic, celiac, superior mesenteric, inferior mesenteric, hypogastric nervous plexuses To add some perspective, the microscopic gut microbiome weighs 1-2 kg, similar to your entire brain or to a pack of rice.Ĭecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canalĪbsorption of electrolytes and water, propulsion of intestinal contents, formation and temporary storage of feces, and defecationĮnteric nervous system: submucosal (Meissner) and myenteric (Auerbach) plexuses In addition to its role in the formation, storage and subsequently defecated of feces, the large intestine also houses an extensive microflora that is essential for our survival. The large intestine is the place where feces are formed by the absorption of water from the passing intestinal contents. Spanning the abdominal and pelvic cavities, it has a length of approximately 1.5 meters, almost equal to the height of a fully grown adult! The large intestine, also known as the large bowel, represents the last part of the gastrointestinal tract.
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