Gallbladder

From Wikipedia, the free encyclopedia Gallbladder Gallbladder Gall Bladder Human anatomy The gallbladder is a hollow organ that sits in a concavity of the liver known as the gallbladder fossa. In adults, the gallbladder measures approximately 10 cm in length and 4 cm in diameter when fully distended.[2] It is divided into three sections: fundus, body, and neck. The neck tapers and connects to the biliary tree via the cystic duct, which then joins the common hepatic duct to become the common bile duct. Microscopic anatomy Gall bladder is #5 The different layers of the gallbladder are as follows:[3] • The gallbladder has a simple columnar epithelial lining characterized by recesses called Aschoff’s recesses, which are pouches inside the lining. • Under the epithelium there is a layer of connective tissue (lamina propria). • Beneath the connective tissue is a wall of smooth muscle (muscularis externa) that contracts in response to cholecystokinin, a peptide hormone secreted by the duodenum. • There is essentially no submucosa separating the connective tissue from serosa and adventitia, but there is a thin lining of muscular tissue to prevent infection. Diagram of Stomach Latin Gray’s System Artery Vein Nerve vesica fellea subject #250 1197 Digestive system (GI Tract) Cystic artery Cystic vein Celiac ganglia, vagus[1] Function The gallbladder stores about 50 mL (1.7 US fluid ounces / 1.8 Imperial fluid ounces) of bile, which is released when food containing fat enters the digestive tract, stimulating the secretion of cholecystokinin (CCK). The bile, produced in the liver, emulsifies fats and neutralizes acids in partly digested food. After being stored in the gallbladder the bile becomes more concentrated than when it left the liver, increasing its potency and intensifying its effect on fats. Most digestion occurs in the duodenum. Most vertebrates have gallbladders (exceptions include the horse, cervids, and the Precursor Foregut The gallbladder (or cholecyst, sometimes gall bladder) is a small non-vital organ which aids in the digestive process and concentrates bile produced in the liver. 1 From Wikipedia, the free encyclopedia rat) while invertebrates do not. This is because vertebrates eat in boluses while invertebrates are constantly eating. To digest a large bolus of food requires a large amount of digestive secretions, hence the presence of a gallbladder. The human gallbladder is shaped like a pear, although the organ’s shape and function vary considerably among other mammalian species; in fact, in some species, such as the lamoids, the gallbladder is absent.[4] Gallbladder Thomas M. Nosek, Ph.D.. Gastrointestinal Physiology. Essentials of Human Physiology. Augusta, Georgia, United State: Medical College of Georgia. pp. p. 30. http://www.lib.mcg.edu/edu/eshuphysio/ program/section6/6ch2/6ch2line.htm. Retrieved on 2007-06-29. [2] Jon W. Meilstrup (1994). Imaging Atlas of the Normal Gallbladder and Its Variants. Boca Raton: CRC Press. pp. 4. ISBN 0-8493-4788-2. [3] "Slide 5: Gall Bladder". JayDoc HistoWeb. University of Kansas. http://www.kumc.edu/instruction/ medicine/anatomy/histoweb/epithel/ epith05.htm. Retrieved on 2007-06-29. [4] C. Michael Hogan. 2008. Guanaco: Lama guanicoe, GlobalTwitcher.com, ed. N. Strömberg Abnormal conditions Gallstones may develop in the gallbladder as well as elsewhere in the biliary tract. If gallstones in the gallbladder are symptomatic and cannot be dissolved by medication or broken into small pieces by ultrasonic waves, surgical removal of the gallbladder, known as cholecystectomy, may be indicated. Other indications for this procedure include porcelain gallbladder and gallbladder cancer. External links • Gallbladder – Mama’sHealth.com. • Diagram of Human Stomach and Gallbladder – Human Anatomy Online, MyHealthScore.com. References [1] Ginsburg, Ph.D., J.N. (2005-08-22). "Control of Gastrointestinal Function". in Retrieved from "http://en.wikipedia.org/wiki/Gallbladder" Categories: Abdomen, Digestive system, Hepatology This page was last modified on 21 May 2009, at 00:28 (UTC). All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.) Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a U.S. registered 501(c)(3) taxdeductible nonprofit charity. Privacy policy About Wikipedia Disclaimers 2