Hepatic veins ultimately from numerous central veins of the liver lobules. None of the hepatic veins have valves. The hepatic veins are divided into an upper and a lower group. The upper three drain the central veins from the right, middle, and left regions of the liver and are larger than the lower group of veins. The lower group of from six to twenty smaller hepatic veins come from the right lobe and the caudate lobe, are in contact with the hepatic tissue, and are valveless. All the veins empty into the inferior vena cava at the back of the liver. Budd–Chiari
British Institute of Organ Studies British Institute of Organ Studies The British Institute of Organ Studies, more commonly known by its acronym BIOS, is a British organisation and registered charity which aims to promote study and appreciation of all aspects of the pipe organ. Further, it acts as a lobbying body to raise awareness of organ issues with appropriate statutory bodies. Membership is open to all. The aims of BIOS are BIOS publishes a quarterly Reporter newsletter and magazine and a yearly Journal which contains articles on organ history. BIOS is also responsible for the National Pipe Organ Register (NPOR), which aims to catalogue all