GALLBLADDERThe gallbladder (or cholecyst or gall bladder) is a small non-vital organ that aids in the digestive process and stores bile produced in the liver.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 8 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.( Author1, http://www.wikipedia/wiki/gallbladder)The gallbladder is a small pear-shaped organ that stores and concentrates bile. The gallbladder is connected to the liver by the hepatic duct. It is approximately 3 to 4 inches (7.6 to 10.2 cm) long and about 1 inch (2.5 cm) wide.The gallbladder is also called a 'gall bladder'. The function of the gallbladder is to store bile and concentrate. Bile is a digestive liquid continually secreted by the liver. The bile emulsifies fats and neutralizes acids in partly digested food. A muscular valve in the common bile duct opens, and the bile flows from the gallbladder into the cystic duct, along the common bile duct, and into the duodenum (part of the small intestine).Sometimes the substances contained in bile crystallize in the gallbladder, forming gallstones. These small, hard concretions are more common in persons over 40, especially in women and the obese. They can cause inflammation of the gallbladder, a disorder that produces symptoms similar to those of indigestion, especially after a fatty meal is consumed. If a stone becomes lodged in the bile duct, it produces severe pain. Gallstones may pass out of the body spontaneously; however, serious blockage is treated by removing the gallbladder surgically.In some cases, the gallbladder must be removed. The surgery to remove the gallbladder is called a cholecystectomy (pronounced co-lee-sist-eck-toe-mee). In a cholecystectomy, the gallbladder is removed through a 5- to 8-inch long cut in your abdomen. Once the gallbladder is removed, bile is delivered directly from the liver ducts to the upper part of the intestine.(Author3,http:www//Complications are rare. When complications occur, they may be in the form of: bleeding, infection and injury to the duct (tube) that carries bile from your gallbladder to your stomach.Some patients also experience diarrhea. The cause of diarrhea after gallbladder removal isn't clear.Bile has various components, some of which are produced by hepatocytes in the liver. The main components include: Water Cholesterol Bile pigments Bile acids (glycocholic and taurocholic acid) Phospholipids (mainly lecithin) Bicarbonate and other ionsThe bile acids are typically conjugated with salt or glycine and are produced by the liver from cholesterol. They are secreted in bile by hepatocytes along the bile canaliculi, which then join the bile duct, and hence into the gall bladder. Ordinarily the concentration of bile salts in bile is 0.8%, however the gall bladder removes water from the bile, concentrating it between meals. It concentrates it up to 5 times (increasing concentration to 4%), before contracting the walls and releasing it into the duodenum once chyme has entered the small intestine from the stomachBile salts are composed of a hydrophilic side, and a hydrophobic side. This means that they are more likely to aggregate to form micelles, with the hydrophobic sides towards the centre and hydrophilic towards the outside. In the centre of these micelles are triglycerides, which are separated from a larger globule of lipid.Pancreatic lipase is able to get to the molecules of triglyceride through gaps between the bile salts, providing a largely increased surface area for digestion. Ordinarily, the micelles in the duodenum have a diameter of around 14-33m. However, it is possible for these to be much smaller, as small as 160nm when using artificial means. Should bile not be present in the duodenum, not all of the lipid is able to be digested during digestion, and a lot of it is passed out in feces. As a result the time taken for the lipid to be broken down would be greatly increased if there was no bile present in the duodenum. This is how the body is able to efficiently digest and absorb lipids for metabolism.Bile acts to some extent as a surfactant, helping to emulsify fats (increasing surface area to help enzyme action), and thus aids in their absorption in the small intestine. The most important compounds are the salts of taurocholic acid and deoxycholic acid. Bile salts combine with phospholipids to break down fat globules in the process of emulsification by associating its hydrophobic side with lipids and the hydrophilic side with water. The phospholipids have a charged "head" which prevents two fat droplets from recombining. Emulsified droplets then are organized into many micelles which increases absorption. Pancreatic lipase acts on the triglyceride material of the fat in the small intestine and breaks them down into two fatty acids and a monoglyceride, which are absorbed by the villi, rebuilt into triglycerides, arranged into chylomicrons, and enter the lacteals inside the intestinal villus. Since bile increases the absorption of fats, it is an important part of the absorption of the fat-soluble vitamins D, E, K and A. Besides its digestive function, bile serves as the route of excretion for the hemoglobin breakdown product (bilirubin) created by breakdown of erythrocytes, which are conjugated by glucuronidation in the liver; it also neutralises any excess stomach acid before it enters the ileum, the final section of the small intestine. Bile salts are also bacteriocidal to the invading microbes that enter with food.( author2,http://www.wikipedia/wiki/Bile).