The anatomy of the stomach may be modified, or the stomach may be bypassed entirely. Surgical removal of the stomach is called a gastrectomy, and removal of the cardia area is a called a cardiectomy. "Cardiectomy" is a term that is also used to describe the removal of the heart. A gastrectomy may be carried out because of gastric cancer or severe perforation of the stomach wall. Fundoplication is stomach surgery in which the fundus is wrapped around the lower esophagus and stitched into place. It is used to treat gastroesophageal reflux disease (GERD). History
There were previously conflicting statements in the academic anatomy community over whether the cardia is part of the stomach, part of the oesophagus or a distinct entity. Modern surgical and medical textbooks have agreed that "the gastric cardia is now clearly considered to be part of the stomach." Etymology
The word stomach is derived from the Latin stomachus which has roots from the Greek word stomachos (στόμαχος), ultimately from stoma (στόμα), "mouth". Gastro- and gastric (meaning "related to the stomach") are both derived from the Greek word gaster (γαστήρ, meaning "belly"). Other animals
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 intestine.
Bismuthides are intermetallic compounds between bismuth and other metals.In 2014 researchers discovered that sodium bismuthide can exist as a form of matter called a “three-dimensional topological Dirac semi-metal” (3DTDS) that possess 3D Dirac fermions in bulk. It is a natural, three-dimensional counterpart to graphene with similar electron mobility and velocity. Graphene and topological insulators (such as those in 3DTDS) are both crystalline materials that are electrically insulating inside but conducting on the surface, allowing them to function as transistors and other electronic devices. While sodium bismuthide (Na3Bi) is too unstable to be used in devices without packaging, it can demonstrate potential applications of 3DTDS systems, which offer distinct efficiency and fabrication advantages over planar graphene in semiconductor and spintronics applications. Halides
The halides of bismuth in low oxidation states have been shown to adopt unusual structures. What was originally thought to be bismuth(I) chloride, BiCl, turns out to be a complex compound consisting of Bi5+9 cations and BiCl2−5 and Bi2Cl2−8 anions. The Bi5+9 cation has a distorted tricapped trigonal prismatic molecular geometry and is also found in Bi10Hf3Cl18, which is prepared by reducing a mixture of hafnium(IV) chloride and bismuth chloride with elemental bismuth, having the structure [Bi+] [Bi5+9] [HfCl2−6]3.: 50  Other polyatomic bismuth cations are also known, such as Bi2+8, found in Bi8(AlCl4)2. Bismuth also forms a low-valence bromide with the same structure as "BiCl". There is a true monoiodide, BiI, which contains chains of Bi4I4 units. BiI decomposes upon heating to the triiodide, BiI3, and elemental bismuth. A monobromide of the same structure also exists.