Organs Pancreas

R Hepatic Duct

The connection between the left and right hepatic ducts forms the common hepatic duct, whose function is to drain bile from the liver. This duct is an important part of the biliary duct system, which transports waste from the liver and aids in digestion by releasing bile. Bile is a greenish-brown fluid that helps digest fats. When measured in adults, the common hepatic duct is approximately six to eight centimeters in length. It is approximately six millimeters in diameter in adults. It is connected to the gallbladder through the cystic duct. Together, they form the common bile duct, which helps transport secretions from the liver and gallbladder down to the intestines. These secretions include proteins, hormones, nutrients, enzymes, and coagulation factors, which are all important in various physiologic functions. Source

Cystic Duct

The cystic duct connects the top of the gallbladder’s neck to the common hepatic duct. It then joins the common bile duct, which meets pancreatic duct before it empties into the duodenum. In the average adult, the cystic duct measures four centimeters in length. The gallbladder stores bile produced in the liver. In order to enter into the duodenum, bile must travel out of the gallbladder, through the cystic duct’s spiral valve, and into the common bile duct. Along with fluid from the pancreas, the bile enters the duodenum through the ampulla of vater. Source

Gallbladder

Your gallbladder is a four-inch, pear-shaped organ. It’s positioned under your liver in the upper-right section of your abdomen. The gallbladder stores bile, a combination of fluids, fat, and cholesterol. Bile helps break down fat from food in your intestine. The gallbladder delivers bile into the small intestine. This allows fat-soluble vitamins and nutrients to be more easily absorbed into the bloodstream. Source

Duodenum

The duodenum is the first and shortest segment of the small intestine. It receives partially digested food (known as chyme) from the stomach and plays a vital role in the chemical digestion of chyme in preparation for absorption in the small intestine. Many chemical secretions from the pancreas, liver and gallbladder mix with the chyme in the duodenum to facilitate chemical digestion. Located inferior to the stomach, the duodenum is a 10-12 inch (25-30 cm) long C-shaped, hollow tube. The duodenum is a part of the gastrointestinal (GI) tract, attached to the pyloric sphincter of the stomach on its superior end and to the jejunum of the small intestine on its inferior end. The innermost layer, the mucosa, lines the inner surface of the duodenum and is in contact with chyme passing through the intestinal lumen. It is made of simple columnar epithelial tissue with microvilli on its surface to increase its surface area and improve the absorption of nutrients. Plentiful mucous glands secrete mucus into the lumen to lubricate the intestinal wall and protect it from friction and acidic chyme. Surrounding the mucosa layer is the submucosa, a layer of connective tissue that supports the other tissue layers. Many blood vessels and nerves pass through the submucosa, while protein fibers give strength and elasticity to the duodenum. Surrounding the submucosa is the muscularis layer that contains the smooth muscle tissue of the duodenum. Contractions of the muscularis mix chyme and propel it through the duodenum toward the rest of the small intestine. Lastly, the serosa is the outermost layer of the duodenum that acts as the outer skin of the intestine. Serous membrane made of simple squamous epithelium provides a smooth, slick surface to prevent friction between the duodenum and the surrounding organs. The serosa also secretes serous fluid to further reduce friction and keep the duodenum’s surface moist. Source

Pylorus of Stomach

The pyloric sphincter is a band of smooth muscle at the junction between the pylorus of the stomach and the duodenum of the small intestine. It plays an important role in digestion, where it acts as a valve to controls the flow of partially digested food from the stomach to the small intestine. The pyloric sphincter plays important roles in controlling the rate of digestion and the direction of chyme movement in the gastrointestinal tract. Food in the stomach is mixed with gastric juice produced by the stomach to form a thick, acidic liquid called chyme. Following a meal, the stomach stores chyme both to begin its digestion and to allow the rest of the digestive system enough time to digest the food thoroughly. The pyloric sphincter remains closed during eating and while the stomach mixes food with gastric juice to form chyme. After the stomach has completed its digestive role, the pyloric sphincter begins to convulse in waves of peristalsis to push chyme toward the pylorus. As each peristaltic wave reaches the pylorus, the pyloric sphincter briefly opens to permit a small mass of chyme to pass into the duodenum. Wave after wave of peristalsis slowly empty the stomach over a period of about 30 minutes to an hour. The pyloric sphincter prevents the regurgitation of chyme from the duodenum into the stomach. It also controls the flow of chyme into the intestine, which provides the intestines with a manageable volume of chyme from which to absorb nutrients. Source

Accessory Pancreatic Duct Papilla

The pancreatic duct is a duct joining the pancreas to the common bile duct to supply pancreatic juice provided from the exocrine pancreas which aids in digestion. The pancreatic duct joins the common bile duct just prior to the ampulla of Vater, after which both ducts perforate the medial side of the second portion of the duodenum at the major duodenal papilla. Most people have just one pancreatic duct. However, some have an additional accessory pancreatic duct, called the Duct of Santorini. An accessory pancreatic duct can be functional or non-functional and may open separately into the second part of the duodenum which is dorsal and usually (in 70%) drains into the duodenum via the minor duodenal papilla. In the other 30% it drains into the main pancreatic duct, which drains into the duodenum via the major duodenal papilla. The main pancreatic duct and the accessory duct both eventually – either directly or indirectly – connect to the second part of the duodenum.

Ampulla of Vater

This is formed by the union of the pancreatic duct and the common bile duct. The ampulla is specifically located at the major duodenal papilla. The ampulla of Vater is an important landmark halfway along the second part of the duodenum that marks the anatomical transition from foregut to midgut, and hence the point where the celiac trunk stops supplying the gut and the superior mesenteric artery takes over. Various smooth muscle sphincters regulate the flow of bile and pancreatic juice through the ampulla: the sphincter of the pancreatic duct, the sphincter of the bile duct, and the sphincter of Oddi. The sphincter of Oddi controls the introduction of bile and pancreatic secretions into the duodenum, as well as preventing the entry of duodenal contents into the ampulla.

Duodenal Papilla

This is an opening of the Common bile duct and Pancreatic duct into the duodenum. The major duodenal papilla is, in most people, the primary mechanism for the secretion of bile and other enzymes that facilitate digestion.

Common Hepatic Duct

L Hepatic Duct

The left hepatic duct and the right hepatic duct transfer bile from the liver. These ducts are formed by the intrahepatic ducts and are a part of a ductal system that leads to the gallbladder. These ducts exit the liver in a common sheath, alongside the branches of the hepatic artery and portal vein. The bile that flows through the right and left hepatic ducts drains into the common hepatic duct. The size of the left hepatic duct depends on the quadrate lobe’s width. It is located behind the portal vein’s left branch. The left hepatic duct enters the upper end of the liver’s umbilical fissure — a groove in the liver that separates the right and left lobes — where it is joined by other duct tributaries that extend to segments II, III, and IV of the liver. Sixty percent of the time, the left hepatic duct unites with the right hepatic duct outside of the liver. The other forty percent of the time, the right posterior and anterior ducts enter the left hepatic duct separately. Source

Common Bile Duct

The common bile duct is a small, tube-like structure formed where the common hepatic duct and the cystic duct join. Its physiological role is to carry bile from the gallbladder and empty it into the upper part of the small intestine (the duodenum). The common bile duct is part of the biliary system. Bile is a greenish-brown fluid that helps digest fats from our food intake. It is produced by the liver and stored and concentrated in the gallbladder until it is needed to help digest foods. When food enters the small intestine, bile travels through the common bile duct to reach the duodenum. Gallstones are hard deposits that form inside the gallbladder when there is too much bilirubin or cholesterol in the bile. Although a person may have gallstones for many years without feeling any symptoms, gallstones can sometimes pass through the common bile duct, causing inflammation and severe pain. If a gallstone blocks the common bile duct, it can cause choledocholithiasis. Symptoms of choledocholithiasis include pain in the right side of the abdomen (biliary colic), jaundice, and fever. Choledocholithiasis can be life-threatening if not diagnosed and treated immediately. Source

Pancreatic Duct

This is a duct joining the pancreas to the common bile duct to supply pancreatic juice provided from the exocrine pancreas which aids in digestion. The pancreatic duct joins the common bile duct just prior to the ampulla of Vater, after which both ducts perforate the medial side of the second portion of the duodenum at the major duodenal papilla. There are many anatomical variants reported but these are quite rare. Most people have just one pancreatic duct. However, some have an additional accessory pancreatic duct, called the Duct of Santorini. An accessory pancreatic duct can be functional or non-functional and may open separately into the second part of the duodenum which is dorsal and usually (in 70%) drains into the duodenum via the minor duodenal papilla. In the other 30% it drains into the main pancreatic duct, which drains into the duodenum via the major duodenal papilla.