Stomach "mouth". The words "gastro-" and "gastric" (meaning related to the stomach) are both derived from the Greek word "gaster" (, meaning "belly"). Although the precise shape and size of the stomach varies widely among different vertebrates, the relative positions of the oesophageal and duodenal openings remain relatively constant. As a result, the organ always curves somewhat to the left before curving back to meet the pyloric sphincter. However, lampreys, hagfishes, chimaeras, lungfishes, and some teleost fish have no stomach at all, with the oesophagus opening directly into the anus. These animals all consume diets that either require little storage of
Feeding tube placed into the duodenum, the first part of the small intestine. These types of tubes are used for individuals who are unable to tolerate feeding into the stomach, due to dysfunction of the stomach, impaired gastric motility, severe reflux or vomiting. These types of tubes must be placed in a hospital setting. A gastric feeding tube (G-tube or "button") is a tube inserted through a small incision in the abdomen into the stomach and is used for long-term enteral nutrition. One type is the percutaneous endoscopic gastrostomy (PEG) tube which is placed endoscopically. The position of the endoscope can be