SAGES Magazine

THE SOUTH AFRICAN GASTROENTEROLOGY REVIEW 2022 | VOLUME 20 | ISSUE 3 | 31 ERCP | A GUIDE FOR NURSES AND ASSISTANTS | Re-printed with permission ANAT OMY AND F UN C T I ON O F T H E B I L E DU C T S The adult liver makes approximately 750ml of bile per 24 hours, usually overnight. The purpose of bile is to help with digestion of fats (it looks, feels and works a lot like washing up liquid) but also to excrete certain waste products (eg surplus cholesterol and blood pigments) into the bowel. Please look at the labels on the picture above. The bile ducts form inside the liver (the right and left hepatic ducts ), come together to form the common hepatic duct which leaves the liver to join the cystic duct (from the gall bladder ) and form the common bile duct, or CBD . The CBD then passes through the head of the pancreas where it joins up with the pancreatic duct (or PD) a few millimetres before they open up into the duodenum . This opening is called the Ampulla of Vater , but everyone just calls it the ampulla. The pancreas makes secretions (or ‘juices’) which help digest protein (lipases). As we are mostly made out of protein, these are very toxic to us and so we are very careful with the pancreas as it is very fragile as well. Pancreatic juices are stored in the pancreas until they are needed (ie there is food in the duodenum), but the liver makes bile constantly so this needs to be stored. At the opening of the ampulla is a small muscle, or sphincter, (called the Sphincter of Oddi) which usually remains shut, but opens when food is sensed in the duodenum. As bile is produced, the pressure builds up against the closed sphincter and the excess bile flows up the cystic duct and into the gall bladder. When food (particularly fatty food) is sensed in the duodenum, a hormone is released which causes the sphincter to open, and the gall bladder 5