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 of pneumonia. There is moderate quality evidence suggesting that the risk of aspiration pneumonia may be reduced by inserting the feeding tube into the duodenum or the jejunum (post-pyloric feeding), when compared to inserting the feeding tube into the stomach. People with dementia may attempt to remove the PEG, which causes complications. A G-tube may instead be used for gastric drainage as a longer term solution to the condition where blockage in the proximal small intestine causes bile and acid to accumulate in the stomach, typically leading to periodic vomiting, or if the vagus nerve is damaged. Where such conditions