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
Built for the Kill the name of the episode. Built For The Kill uses a graphical approach to catch the audiences attention, often showing inner workings of the predatory animals (e.g. showing a snake's "Jacobson Organ" inside its mouth) by using diagrams. Some effects seen are used to show the audience what they can't really see, but is there (such as the electricity coming from an Electric Ray or the sound waves used in Echo Location). This graphical approach to nature is meant to make the documentary more interesting to watch. "Built for the Kill"s classic opening was a montage of creatures featured in